CEMENTED TOTAL HIP ARTHROPLASTY AND IMPACTION BONE GRAFTING IN YOUNG PATIENTS - - PATIENTS YOUNG IN GRAFTING BONE IMPACTION AND ARTHROPLASTY TOTALHIP CEMENTED MARLOES W.J.L. SCHMITZ 2017 SCHMITZ W.J.L. MARLOES

CEMENTED TOTAL HIP ARTHROPLASTY AND IMPACTION BONE GRAFTING IN YOUNG PATIENTS

MARLOES W.J.L. SCHMITZ CEMENTED TOTAL HIP ARTHROPLASTY AND IMPACTION BONE GRAFTING IN YOUNG PATIENTS

Marloes W.J.L. Schmitz The publication of this thesis was kindly supported by:

Radboud Universiteit Nijmegen Nederlandse Orthopaedische Vereniging Stichting OrthoResearch Össur Link & Lima Nederland Annafonds│NOREF BISLIFE Foundation Interactive Studios Livit Orthopedie ChipSoft

Colofon Author: Marloes W.J.L. Schmitz Cover design en lay-out: Miranda Dood, Mirakels Ontwerp Printing: Gildeprint - The Netherlands ISBN: 978-90-9030232-4

© Marloes W.J.L. Schmitz, 2017 All rights reserved. No part of this publication may be reproduced or transmitted in any form by any means, without permission of the author. CEMENTED TOTAL HIP ARTHROPLASTY AND IMPACTION BONE GRAFTING IN YOUNG PATIENTS

Proefschrift

Ter verkrijging van de graad van doctor aan de Radboud Universiteit Nijmegen op gezag van de rector magnificus prof. dr. J.H.J.M. van Krieken, volgens besluit van het college van decanen in het openbaar te verdedigen op woensdag 27 september 2017 om 14:30 uur precies

door

Marloes Wilhelmina Johanna Louisa Schmitz

geboren op 31 augustus 1985, te Blerick Promotor Prof. dr. R.P.H. Veth

Copromotoren Dr. B.W. Schreurs Dr. J.W.M. Gardeniers

Manuscriptcommissie Prof. dr. W.B. van den Berg Prof. dr. S.J. Bergé Prof. dr. B.J. van Royen (VUmc)

TABLE OF CONTENTS

Chapter 1 Introduction, general background and thesis outline p.08

Chapter 2 Hip resurfacing in patients under 55 years of age p.30 Nederlands Tijdschrift voor Geneeskunde 2011;155:A3186

Chapter 3 Long-term results of cemented total hip arthroplasty in p.48 patients younger than 30 years and the outcome of subsequent revisions BMC Musculoskeletal Disorders 2013; Jan 22;14:37

Chapter 4 Results of the cemented Exeter femoral component in p.68 patients under 40 years of age. An update at 10 to 20 years follow-up Bone and Joint Journal 2017 feb;99-B(2):192-198

Chapter 5 Acetabular reconstructions with impaction bone-grafting p.88 and a cemented cup in patients younger than fifty years old. A concise follow-up, at twenty-seven to thirty-five years, of a previous report Accepted for publication in the Journal of Bone and Joint Surgery

Chapter 6 Clinical and radiological outcome of the cemented p.104 Contemporary acetabular component in patients < 50 years of age Bone and Joint Journal 2013;95-B:1617–25.

6 Chapter 7 Systematic review: lack of evidence for the success of revision p.126 arthroplasty outcome in younger patients Submitted to Hip International

Chapter 8 A new approach to improve cemented cup survival in p.144 primary total hip arthroplasty in young patients: acetabular impaction bone grafting A preliminary report with a minimum follow-up of two years

Chapter 9 Summary and general discussion p.160

Chapter 10 Nederlandse samenvatting en algemene discussie p.178

Dankwoord p.196 List of publications, presentations and posters p.202 Curriculum Vitae p.207

7

Introduction, general background and thesis outline

CHAPTER 1 Cemented total hip arthroplasty and impaction bone grafting in young patients

INTRODUCTION 1 Total hip arthroplasty (THA) is one of the most successful and cost effective operations in medicine. It has even been called the operation of the 20th century.1 Throughout the world large numbers of THA are performed annually. In the UK and the USA together over 500.000 THA procedures are performed every year.2 In the Netherlands, according to the Dutch Arthroplasty Registry (LROI), around 28.000 THA were implanted in 2015.3 Approximately 93% of operations are performed for severe osteoarthritis with intractable pain and functional limitations.4 For those patients not responding to conservative measurements, THA is an effective treatment. The survival outcomes in patients over 65 years can be considered excellent.5-7 Patients regain their mobility and their health status improves as result of a decrease in pain and increase in quality of life4, 8, 9. The improvements made in THA over the years have led to high expectations by patients and strict survival criteria as described for example in the criteria of the National institute for Health and Care Excellence (NICE) and the Orthopaedic Data Evaluation Panel (ODEP) ratings.10, 11 Nowadays the long term survival rate of the prosthesis in older patients is expected to be 95% or more after ten years of follow-up. Due to the success of THA in older patients over the past few years, THA are currently offered to younger patients in increasing numbers. These younger patients can suffer from primary end-stage osteoarthritis, however, end- stage secondary osteoarthritis is a more common diagnosis. In the Netherlands, common causes of end-stage secondary osteoarthritis in patients receiving a THA at an age of under 50 are for example developmental dysplasia of the hip (DDH), osteonecrosis of the femoral head, rheumatoid arthritis and post-Perthes’ disease.3 Literature shows comparable early results of THA in patients younger than 50 compared to older patients. This is in contrast to the long-term results which still are inferior in young patients.3, 5-7, 12-20 This less successful survival and the fact that many young patients will outlive their primary total hip implant due to their longer life expectancy both contribute to inevitably higher numbers of revision procedures in these younger patients21.Therefore these young patients must be treated with specific attention. We must focus on techniques and materials that can guarantee durable solutions in order to facilitate inevitable future revisions. It is imperative that patients need to be informed on their long-term expected survival, their chances on facing future revisions and the expected outcome of these revisions.22-26

10 CHAPTER 1

Introduction, general background and thesis outline

This thesis focuses on THA in this specific category of patients who are younger than 50 years at the moment of their primary THA implantation. It is aimed at investigating 1 the long-term results of the cemented THA, the importance and technique of subsequent revisions in young patients and improving the survival and possibilities to revise by using a biological approach during the primary THA.

THE HISTORY OF CEMENTED THA

Sir John Charnley introduced the concept of a cemented THA as early as 1959 and used polymethylmethacrylate bone cement to fill the gaps between the implant and bone in order to create stability of the prosthesis.27 This was a few decades after the introduction of the total hip arthroplasty in 1923, when Smith-Petersen performed his first trial of a hip replacement using a glass cup between the femoral head and the acetabulum.28 The concept of cemented fixation in orthopedic implants came from Haoush who used dental cement for prosthetic fixation.29, 30 Unfortunately, the results were not successful. In retrospect, his unsuccessful results were known to be caused by the designs of his used implants. Charnley introduced a new design and replaced the polytetrafluorethylene initially used for the acetabular cup by polyethylene in 1963, because of a high wear rate of the polytetrafluorethylene. This concept is still the base for many new cemented designs that have been developed throughout the last decades.

Cementing technique The developments in the technique of cementing have been well described by Breusch and Malchau.31 The first generation cementing techniques already emphasized the importance of pressurizing the cement into the bone in an attempt to create an adequate cement pressure. This was done by means of ‘thumbing’ down the cement from proximal to distal in the femur, the so called ‘finger-packing’ technique. The cement mixing technique consisted of hand mixing the two components in an open bowl. The cement was stuffed into the femoral canal and in the prepared acetabulum by hand. The second generation cementing technique included the use of a distal intramedullary cement restrictor, which allowed for cement containment and better pressurization. The cement gun added the possibility to fill the femoral canal in a retrograde manner, to create higher

11 Cemented total hip arthroplasty and impaction bone grafting in young patients

cement pressure distally than proximally. By introducing pressurization a method was 1 found to overcome blood pressure and consequently blood entrapment into the cement- bone interface was prevented which improved the results of cemented THA.32 Bone lavage prior to cementation was introduced after the observation that it aided the cement penetration into the bone. New concepts were pulsatile lavage, stem centralizing devices and vacuum mixing of the cement, which have shown to reduce the long-term revision risk. The procedure that includes all these steps is called the third generation cementing technique (Table I). Figure 1 illustrates some differences between the first and third cementing technique that can be seen on a anteroposterior radiograph of the hip. Long- term result studies reporting on the outcome in younger patients often include the first and second generation cementing techniques.33, 34 This demands for careful evaluation of long-term results when comparing different types of fixation techniques, as the results of the cemented prosthesis have greatly improved with the abovementioned developments.

TABLE I. Description of the different generation cementing techniques Evolution of cementing techniques First Generation Second Generation Third Generation Bone-bed preparation (bulb syringe Pulsatile lavage for thorough bone- Limited bone-bed preparation irrigation/drying) bed preparation Unplugged femur Distal femur cement restrictor Improved distal cement restrictor Stiff cement and ‘finger packing Retrograde cement application with Retrograde cement application via technique’ cement gun cement gun Femoral and acetabular cement Femoral pressurizer and acetabular Digital pressurization pressurization pressurizer Open atmosphere cement mixing Vacuum mixing, stem centralizer, Hand mixing of cement by hand cement spacers

Prosthesis Unfortunately, when surgeons started using cemented THA in patients under the age of 50, the results were less favourable compared to older patients. Furthermore, a critical paper of Hungerford et al. caused suspicion regarding the use of cemented THA in 1988.35, 36 Problems such as loosening of the prosthesis and osteolysis were thought to be caused by the use of cement. In retrospect, these problems were not caused by the cement but by the polyethylene particles generated by wear of the cup which indirectly caused loss of bone around the prosthesis and finally to failure of the prosthesis. Professor

12 CHAPTER 1

Introduction, general background and thesis outline

William Harris introduced the term ‘particle disease’ to stress the importance of particles generated by a prosthesis for induction of host response. 1

A B

FIGURE 1. Cementing techniques in total hip arthroplasty 1a: example of a well cemented THA, third generation cementing technique. 1b: example of an insufficient cementing technique.

This process starts with very small (micrometers and less in size) polyethylene particles accumulating in the joint cavity due to friction of the metal head against the polyethylene during movement.37,38 These particles stimulate periprosthetic cells to express pro- inflammatory and pro-osteoclastic cytokines leading to increased activity and survival of osteoclasts and inhibiting the osteogenic activity of osteoblasts. As a result, osteoresorption predominates over osteogenesis, eventually leading to macroscopic bone defects around the implant. This periprosthetic osteolysis often precedes aseptic loosening and unfortunately is asymptomatic for a long time. Later, the same problems were also seen in noncemented THA, as the problems caused by wear for both fixations were comparable. However, correctly or not, the thesis that cement was responsible for these problems was the start

13 Cemented total hip arthroplasty and impaction bone grafting in young patients

of a shift towards the increased use of noncemented designs and the use of alternate 1 bearings, initially in younger patients.37 As mentioned before, noncemented fixation techniques show osteolysis as well, indicating that it was not the cement that caused the described problems but especially the polyethylene wear.39 Now the polyethylene was seen as the cause of osteolysis, and new types of polyethylene such as highly cross-linked and Vitamin E polyethylene were introduced.40-42 In addition, other bearing types were introduced, for example the ceramics-on-ceramics and the metal-on-metal bearings. However, the outcomes in young patients remained less favorable compared to older patients. In 1996, as an auspicious solution the resurfacing prosthesis was introduced for these younger patients.43, 44 This type of prosthesis was not a completely new concept since several different types of resurfacing hip prostheses had already been developed and introduced on the market in the 1970’s. But the materials used back in those days were very sensitive to wear, especially because a large metal head and a large early type of polyethylene cup were used. This resulted in polyethylene debris, which caused extensive osteolysis. At that time the osteolysis was not recognized as the cause of failure and problems were for example attributed to avascular necrosis of the underlying bone of the femoral head. The newly designed resurfacing implants were based on a large metal head and a large metal cup; this resulted in a metal-on-metal articulation. Initially these new implants were successful, and they were immediately produced by many different manufacturers and implanted by many orthopedic surgeons all over the world. However, large differences in the 5-year survival rates between all these different implants were shown in literature and questions were subsequently raised on the safety of these type of implants.45 At the same time more knowledge was gained on the metal-on-metal articulations in THA.46,47 Especially the articulations using a large metal head, used widely in young patients, showed the same problems and complications as the older types of resurfacing prosthesis e.g. neck fractures and osteolysis. In addition another new problem was seen, even in well functioning prostheses: high metal serum concentrations, which could even reach toxic levels and were a sign of high wear of the prosthesis, leading to revisions in some cases. Intra-operative pseudo tumors could be found, which were formed by soft tissue reacting to the metal ions. In addition, the trend to use large metal heads on a standardized femoral component, an articulation comparable to the resurfacing THA and very attractive to prevent dislocations, led to a new problem again: coupling of the

14 CHAPTER 1

Introduction, general background and thesis outline large metal head on the small taper of the stem resulted in a second source of metal debris (truniosis).48 In the mean time the survival of cemented THA in young patients, using 1 modern cementation techniques, improved.49, 50 These good results and the unexpected problems seen in metal-on-metal articulations led to the question how young patients with end-stage osteoarthritis should be treated. This yielded to an interesting discussion once again. Regarding the femoral stems, currently almost no difference in survival is seen between cemented and noncemented components. However the acetabular component is still the weakest link in the THA in younger patients.17, 19, 51-56 So far no consensus exists on the use of either a cemented or a noncemented prosthesis in younger patients. Therefore the aim of the research described in this thesis is to investigate if a cemented THA is a reliable long-term solution in younger patients with end-stage osteoarthritis

BONE STOCK DEFICIENCY

Another very important issue in THA is loss of bone stock and how to address it. In both primary and revision hip surgery this can be a technical challenge. Especially in younger patients who often suffer from secondary osteoarthritis as a result of underlying diseases, e.g. developmental dysplasia of the hip, osteonecrosis, trauma or juvenile rheumatoid arthritis, an associated loss of the acetabular bone stock is often seen. Bone loss on the acetabular side will harm the outcome of the acetabular component, both in cemented and noncemented cups. In young patients it is important to not simply use more metal to augment or compensate for the bone loss, but to use a biological solution. Young patients will often outlive their THA due to a longer life expectancy and they will need good bone stock in case of (re)-revision. Loosening of an implant, primary or revision, will definitely lead to bone stock loss and any technique to prevent bone stock loss at the primary or revision surgery seems to be the most attractive solution. When performing THA surgery, initial stable socket fixation, restoring the center of rotation and optimizing contact between host bone and cement and also the implant are the important factors to create a long-term stable fixation. This can be achieved by reconstructing any bone stock loss in a biological way at the time of primary THA.57 It is important to study the anteroposterior pelvic and cross table lateral radiographs of the hip to determine any amount and the location of existing osteolysis. CT scans can

15 Cemented total hip arthroplasty and impaction bone grafting in young patients

be performed in order to determine the exact amount and location of bone loss even 1 more accurately, especially on the acetabular side. Defects can be classified according to the system of the American Academy of Orthopaedic Surgeons Committee of the Hip (AAOS) as can be seen in table II and figure 2.58

TABLE II. The classifications system of acetabular bone defects according to the American Academy of Orthopaedic Surgeons.

Type I Segmental defect

Type II Cavitary defect

Type III Combined defect

Type IV Pelvic discontinuity

Type V Arthrodesis

FIGURE 2. This image shows different types of acetabular bone defects, illustrating the difference between a segmental and a cavitary defect.

There are many options to address bone stock loss in revision surgery, but they do not always include reconstruction of the bone stock itself. Jumbocups or large hemispherical

16 CHAPTER 1

Introduction, general background and thesis outline cups are commonly used in order to fill these defects, without actually restoring bone stock.59 This results in an even more technically difficult situation when facing further 1 revisions of these prostheses as bone stock is initially not restored and defects often become even more extensive. Acceptable survival results have been published but knowledge lacks on the revisability of these cups when they fail.60-62 Bilobed implants, eccentric or oblong acetabular implants have been designed to achieve an increased prosthesis-bone contact in case of acetabular defects and restore the anatomical hip centre of rotation but results are not all that favorable and again bone stock is not restored.63-65 The use of antiprotrusio cages has been diminished over the last years as more contemporary technologies have become available, however often the outcome was very acceptable.66, 67 More recently custom made implants were introduced to treat extremely large defects.68 No long-term results of these implants are known yet. Techniques that have emphasized reconstructing bone loss are impaction bone grafting (IBG) using autograft, allograft or mixes and of course structural allografts. Structural allografts have shown acceptable long-term results in AAOS type III defects.69 Trabecular metal acetabular implants have a potential to provide a better environment for biologic fixation when limited host bone is available. Multiple sizes and shapes of these acetabular augments can be used for various sizes of acetabular defects. The use of such a modular system allows biological fixation rather than mechanical fixation and can avoid the use of structural allografts. In case of a massive uncontained or contained defect, a trabecular metal cup-cage construct can be used. Short-term clinical and radiographic results are promising, but long-term durability is not yet known.70 Other potential complications include the potential for debris generation, fatigue failure and no restoration of bone stock for future revisions. IBG for the acetabulum was developed by Slooff in our institution in 1979 and was based on the concept of Hastings and Parker who reconstructed contained acetabular defects in hips with protrusio acetabuli with the use of noncompacted small particle bone grafts.71 McCollum et al adapted this technique using wafers of bone.72 Slooff became inspired by these techniques that used non-compressed chips or wafers of bone. The disadvantage of these techniques however was the limited contact between the cement and the bone grafts due to gelfoam strips which were placed around the periphery of the graft to prevent interposition of cement between it and the articular surface. Slooff recognized that due to this gelsheet between the graft and the cement no penetration of the cement

17 Cemented total hip arthroplasty and impaction bone grafting in young patients

into the graft could occur. To improve stability Slooff decided to apply impaction of the 1 bone grafts with a trial socket prosthesis. At time of the initial surgeries a metal mesh was placed on top of the impacted bone graft to prevent extensive cement-graft penetration, as it was thought that the cement could be harmful for the incorporation of the bone graft. In case of a segmental bone defect of the medial wall, a medial wall mesh was used to close this bone defect. The bone graft was impacted on top of this mesh and a second mesh was placed on top of the graft. The bone graft was impacted with an acetabular trial prostheses and the final cup was chosen one size smaller than the last trial cup used for impaction to allow for a 2 mm cement layer all around the new cup. Histological studies in a goat model showed that the bone grafts did incorporate well, despite the fact that they were in contact with the cement.73 To prove the concept, biopsies were taken at any revision surgery in patients in whom a primary or revision cemented THA with impaction grafting had been performed earlier. The results in the first published series showed completely incorporated grafts at 28 months.74 In a follow-up study of 24 biopsies, in 21 hips good results and incorporation was shown up to 15 years postoperatively.75 The process of incorporation of these bone grafts was also studied by Heekin et al. 76 Post- mortem analysis showed revascularised and gradually incorporated grafts. Some principles of the IBG technique have proven to be essential in order to achieve success. Smaller chips (2-4mm) are not recommended for the acetabular revisions, large bone chips (8-12 mm) produce better cup stability.77 In addition, impaction should not be performed by compressing the bone grafts with the reversed reamer technique as this leads to inferior cup stability.78 The use of a metal mallet is highly recommended. The success of this technique has also been described in younger patients.79 IBG has proven to be a successful technique in primary and revision surgery in the presence of an acetabular bone stock defect.79-82 This led to the introduction in primary THA in young patients of a cemented THA in combination with IBG in absence of a bone stock defect as it can improve bone cement interdigitation and thereby improve the cup survival. This new development will be addressed in this thesis.

18 CHAPTER 1

Introduction, general background and thesis outline

1

FIGURE 3. Acetabular impaction bone grafting in hips without acetabular bone defects a) no acetabular bone defects are seen and no mesh is used. b) The femoral head was morselized with a rongeur to provide cancellous bone chips with a diameter of 0.7-1.0 centimeters. In case the femoral head was affected and sclerotic, a femoral head allograft from the bone bank was obtained. c) With a metal impacter, the bone chips are compressed tightly. d) Bone cement is introduced in a relatively viscous state and is pressurized to force bone cement into the graft before placement of the cup.

OUTLINE OF THIS THESIS

At Radboudumc patients have always received a cemented THA. In case of a bone stock deficiency IBG was added. Therefore the primary objective of this thesis is to evaluate the longterm results of cemented THA. For this purpose the clinical and radiographic results of cemented THA with or without IBG will be investigated. Furthermore, the objective is to investigate if IBG may improve the results of cemented THA in young patients in absence of an acetabular bonestock defect. Finally it will be investigated what amount of reliable information is available regarding long-term arthroplasty survival of primary

19 Cemented total hip arthroplasty and impaction bone grafting in young patients

THA that includes the outcome of subsequent revision arthroplasty as well. 1 At the start of this thesis the resurfacing hip prosthesis is being used in increasing numbers in young patients. Although these types of prosthesis have never been used at Radboudumc, this thesis will start with presenting a state-of-the-art of this frequently used type of prosthesis in young patients.

Questions addressed in this thesis: 1. Resurfacing hip arthroplasty in younger patients: what is the state-of-the-art and what should we advise patients under 55 years of age? 2. What is the long-term outcome of a cemented total hip arthroplasty in patients under 30 years, and what is the outcome of subsequent revisions in this group of patients? 3. Can the cemented highly polished Exeter stem be used as a long-term solution in patients under 40 years old? 4. What are the 30-year radiographic and clinical outcomes of primary and revision acetabular reconstructions with impaction bone grafting in patients less than 50 years old? 5. What is the clinical and radiographical outcome of the Contemporary acetabular component in patients under 50 years old, with and without IBG? 6. What is known of both the survival data of primary THA and the survival of the subsequent revisions within the same cohorts of patients under 50 years of age? 7. Can we safely use impaction bone grafting in patients without an acetabular defect in order to improve future long-term outcome?

Chapter 2 presents the state of the art of THA in young patients at the time of publication in 2011 to inform patients and colleagues of other specialties such as general practitioners on the developments, survival and complications of resurfacing arthroplasty. It includes a literature review on the long-term survival results of the resurfacing prosthesis and, in addition, it summarizes the knowledge on complications and drawback alerts which received a lot of media attention at that time. In the very young patients under 30 years of age, literature on long-term results of THA is scarce. The long-term results of a cemented THA in patients under 30 are presented in Chapter 3. Additionally the survival outcome of the subsequent revisions in

20 CHAPTER 1

Introduction, general background and thesis outline the same cohort of patients is investigated and described. In Chapter 4 the focus is specifically on the stem survival. From 1998 onwards only 1 the Exeter stem (Stryker-Howmedica, Newbury, UK) has been used in our institute. No long-term evidence for the use of the Exeter stem in young patients under 40 years is known and we aimed to investigate whether the long-term results can support our consistent use of this cemented femoral component in younger patients. The clinical and radiographic outcome at minimum ten year follow-up are described. Special attention has been given to radiographic analysis to check for alarming signs as the early indication of aseptic loosening and subsequently as proof for safe use of this femoral component in this age group. In Chapter 5 we evaluate the 30-year radiographic and survival results of primary and revision acetabular reconstructions with the use of IBG as developed by Slooff in the Radboudumc in patients under 50. Chapter 6 describes the clinical and radiographical outcome of the Contemporary acetabular component in patients under 50, both with and without IBG. A next step in research regarding THA and revision arthroplasty would be to combine the results of primary and revision arthroplasties in a cohort of young patients, because the revisability is very important for young patients. In Chapter 7 a systemic literature is performed in order to describe what is known on the combined outcome of both the survival data of primary THA as well as the survival of subsequent revisions in the same cohorts of young patients under 50. In Chapter 8 the next step, ‘Can IBG safely be used in patients without any bone stock defects’ in younger patients using a cemented THA and IBG is described. Can this new technique safely be used in patients without any bone stock defects in order to be one step ahead and improve the bone-cement interdigitation without any early complications? This is the first step to evaluate if this concept might improve bone stock at time of revisions as well, as the aim is to improve the long-term results of revision arthroplasty in younger patients as well.

21 Cemented total hip arthroplasty and impaction bone grafting in young patients

REFERENCES 1 1. Learmonth ID, Young C, Rorabeck C. The operation of the century: total hip replacement. Lancet. 2007;370(9597):1508-19. 2. Kurtz SM, Ong KL, Lau E, Bozic KJ. Impact of the economic downturn on total joint replacement demand in the United States: updated projections to 2021. J Bone Joint Surg Am. 2014;96(8):624-30. 3. LROI Report 2014. Arthroplasty in the Picture. Annual Report of the Dutch Arthroplasty Register 2014. 4. Shan L, Shan B, Graham D, Saxena A. Total hip replacement: a systematic review and meta- analysis on mid-term quality of life. Osteoarthritis and cartilage / OARS, Osteoarthritis Research Society. 2014;22(3):389-406. 5. Australian Orthopaedic Association National Joint Replacement Registry. Annual Report. Adelaide: AOA;2015. 6. 12th Annual Report 2015 National Joint Registry for England, Wales, Northern Ireland and the Isle of Man. 7. Swedish Hip Arthroplasty Register Annual Report 2013. 8. Smith GH, Johnson S, Ballantyne JA, Dunstan E, Brenkel IJ. Predictors of excellent early outcome after total hip arthroplasty. Journal of orthopaedic surgery and research. 2012;7:13. 9. Rubin LE, Blood TD, Defillo-Draiby JC. Total Hip and Knee Arthroplasty in Patients Older Than Age 80 Years. The Journal of the American Academy of Orthopaedic Surgeons. 2016;24(10):683-90. 10. NICE National Institute for HEalth and Care Excellence. Total hip replacement and resurfacing arthroplasty for end-stage arthritis of the hip. Technology appraisal guidance [TA304] [Last accessed 25th of september 2016]. Published Date: 26 February 2014:[Available from: https:// www.nice.org.uk/guidance/ta304. 11. ODEP Orthopaedic Data Evaluation Panel. ODEP Criteria [updated Version November 2015last accessed 25th September 2016]. Available from: http://www.odep.org.uk/ ODEPRatings/ODEPCriteria.aspx. 12. Busch V, Klarenbeek R, Slooff T, Schreurs BW, Gardeniers J. Cemented hip designs are a reasonable option in young patients. Clinical orthopaedics and related research. 2010;468(12):3214-20.

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13. de Kam DC, Gardeniers JW, Hendriks JC, Veth RP, Schreurs BW. Cemented polyethylene cups in patients younger than 40 years. Clinical orthopaedics and related research. 2009;467(7):1753- 1 64. 14. de Kam DC, Gardeniers JW, Veth RP, Schreurs BW. Good results with cemented total hip arthroplasty in patients between 40 and 50 years of age. Acta orthopaedica. 2010;81(2):165-70. 15. Girard J, Glorion C, Bonnomet F, Fron D, Migaud H. Risk factors for revision of hip arthroplasties in patients younger than 30 years. Clinical orthopaedics and related research. 2011;469(4):1141-7. 16. Hailer NP, Garellick G, Karrholm J. Uncemented and cemented primary total hip arthroplasty in the Swedish Hip Arthroplasty Register. Acta orthopaedica. 2010;81(1):34-41. 17. Hwang KT, Kim YH, Kim YS, Choi IY. Cementless total hip arthroplasty with a metal-on- metal bearing in patients younger than 50 years. The Journal of arthroplasty. 2011;26(8):1481- 7. 18. Innmann MM, Gotterbarm T, Kretzer JP, Merle C, Ewerbeck V, Weiss S, et al. Minimum ten-year results of a 28-mm metal-on-metal bearing in cementless total hip arthroplasty in patients fifty years of age and younger. International orthopaedics. 2014;38(5):929-34. 19. Kim YH, Kim JS, Park JW, Joo JH. Comparison of total hip replacement with and without cement in patients younger than 50 years of age: the results at 18 years. The Journal of bone and joint surgery British volume. 2011;93(4):449-55. 20. Kim YH, Park JW, Kim JS, Kim IW. Twenty-Five- to Twenty-Seven-Year Results of a Cemented vs a Cementless Stem in the Same Patients Younger Than 50 Years of Age.The Journal of arthroplasty. 2015. 21. Kurtz SM, Lau E, Ong K, Zhao K, Kelly M, Bozic KJ. Future young patient demand for primary and revision joint replacement: national projections from 2010 to 2030. Clinical orthopaedics and related research. 2009;467(10):2606-12. 22. Comba F, Buttaro M, Pusso R, Piccaluga F. Acetabular revision surgery with impacted bone allografts and cemented cups in patients younger than 55 years. International orthopaedics. 2009;33(3):611-6. 23. Raut VV, Siney PD, Wroblewski BM. Revision of the acetabular component of a total hip arthroplasty with cement in young patients without rheumatoid arthritis. J Bone Joint Surg Am. 1996;78(12):1853-6. 24. Streit MR, Weiss S, Andreas F, Bruckner T, Walker T, Kretzer JP, et al. 10-year results of the uncemented Allofit press-fit cup in young patients. Acta orthopaedica. 2014;85(4):368-74.

23 Cemented total hip arthroplasty and impaction bone grafting in young patients

25. Te Stroet MA, Rijnen WH, Gardeniers JW, van Kampen A, Schreurs BW. Satisfying Outcomes 1 Scores and Survivorship Achieved With Impaction Grafting for Revision THA in Young Patients. Clinical orthopaedics and related research. 2015;473(12):3867-75. 26. Malcolm TL, Szubski CR, Nowacki AS, Klika AK, Iannotti JP, Barsoum WK. Activity levels and functional outcomes of young patients undergoing total hip arthroplasty. Orthopedics. 2014;37(11):e983-92. 27. Charnley J. Arthroplasty of the hip. A new operation. Lancet. 1961;1(7187):1129-32. 28. Smith-Petersen MN. Evolution of mould arthroplasty of the hip joint. The Journal of bone and joint surgery British volume. 1948;30B(1):59-75. 29. J. Anderson FN, J v. Pickstone. Surgeons, Manufactureres and Patients. A Transatlantic History of Total Hip Replacement: Palgrave Macmillan Ltd; 2007. 236 p. 30. B.M. Wroblewski PAF, P.D. Siney. Charnley Low-Frictional Torque Arthroplasty of the Hip: Springer; 2016. 31. S.J. Breusch HM. The Well-Cemented Total Hip Arthroplasty: Springer; 2005. 32. Slooff TJ. A cement syringe. Acta orthopaedica Belgica. 1969;35(6):1012-4. 33. Garcia-Cimbrelo E, Cruz-Pardos A, Cordero J, Sanchez-Sotelo J. Low-friction arthroplasty in patients younger than 40 years old: 20- to 25-year results. The Journal of arthroplasty. 2000;15(7):825-32. 34. Lampropoulou-Adamidou K, Georgiades G, Vlamis J, Hartofilakidis G. Charnley low-friction arthroplasty in patients 35 years of age or younger. Results at a minimum of 23 years. The bone & joint journal. 2013;95-B(8):1052-6. 35. Hungerford DS, Jones LC. The rationale of cementless revision of cemented arthroplasty failures. Clinical orthopaedics and related research. 1988(235):12-24. 36. Jones LC, Hungerford DS. Cement disease. Clinical orthopaedics and related research. 1987(225):192-206. 37. Harris WH. Osteolysis and particle disease in hip replacement. A review. Acta orthopaedica Scandinavica. 1994;65(1):113-23. 38. Gallo J, Goodman SB, Konttinen YT, Raska M. Particle disease: biologic mechanisms of periprosthetic osteolysis in total hip arthroplasty. Innate immunity. 2013;19(2):213-24. 39. Goetz DD, Smith EJ, Harris WH. The prevalence of femoral osteolysis associated with components inserted with or without cement in total hip replacements. A retrospective matched-pair series. J Bone Joint Surg Am. 1994;76(8):1121-9.

24 CHAPTER 1

Introduction, general background and thesis outline

40. Beksac B, Salas A, Gonzalez Della Valle A, Salvati EA. Wear is reduced in THA performed with highly cross-linked polyethylene. Clinical orthopaedics and related research. 2009;467(7):1765- 1 72. 41. Wolf C, Krivec T, Blassnig J, Lederer K, Schneider W. Examination of the suitability of alpha- tocopherol as a stabilizer for ultra-high molecular weight polyethylene used for articulating surfaces in joint endoprostheses. Journal of materials science Materials in medicine. 2002;13(2):185-9. 42. Wolf C, Lederer K, Bergmeister H, Losert U, Bock P. Animal experiments with ultra-high molecular weight polyethylene (UHMW-PE) stabilised with alpha-tocopherol used for articulating surfaces in joint endoprostheses. Journal of materials science Materials in medicine. 2006;17(12):1341-7. 43. McMinn D, Treacy R, Lin K, Pynsent P. Metal on metal surface replacement of the hip. Experience of the McMinn prothesis. Clinical orthopaedics and related research. 1996(329 Suppl):S89-98. 44. Wagner M, Wagner H. Preliminary results of uncemented metal on metal stemmed and resurfacing hip replacement arthroplasty. Clinical orthopaedics and related research. 1996(329 Suppl):S78-88. 45. McMinn DJ, Daniel J, Ziaee H, Pradhan C. Indications and results of hip resurfacing. International orthopaedics. 2011;35(2):231-7. 46. Girard J, Bocquet D, Autissier G, Fouilleron N, Fron D, Migaud H. Metal-on-metal hip arthroplasty in patients thirty years of age or younger. J Bone Joint Surg Am.92(14):2419-26. 47. Zywiel MG, Sayeed SA, Johnson AJ, Schmalzried TP, Mont MA. Survival of hard-on-hard bearings in total hip arthroplasty: a systematic review. Clinical orthopaedics and related research. 2011;469(6):1536-46. 48. Bishop N, Witt F, Pourzal R, Fischer A, Rutschi M, Michel M, et al. Wear patterns of taper connections in retrieved large diameter metal-on-metal bearings. Journal of orthopaedic research: official publication of the Orthopaedic Research Society. 2013;31(7):1116-22. 49. De Kam DC, Busch VJ, Veth RP, Schreurs BW. Total hip arthroplasties in young patients under 50 years: limited evidence for current trends. A descriptive literature review. Hip international: the journal of clinical and experimental research on hip pathology and therapy. 2011;21(5):518-25. 50. Morshed S, Bozic KJ, Ries MD, Malchau H, Colford JM, Jr. Comparison of cemented and uncemented fixation in total hip replacement: a meta-analysis. Acta orthopaedica. 2007;78(3):315-26.

25 Cemented total hip arthroplasty and impaction bone grafting in young patients

51. Keener JD, Callaghan JJ, Goetz DD, Pederson DR, Sullivan PM, Johnston RC. Twenty-five- 1 year results after Charnley total hip arthroplasty in patients less than fifty years old: a concise follow-up of a previous report. J Bone Joint Surg Am. 2003;85-A(6):1066-72. 52. McCullough CJ, Remedios D, Tytherleigh-Strong G, Hua J, Walker PS. The use of hydroxyapatite-coated CAD-CAM femoral components in adolescents and young adults with inflammatory polyarthropathy: ten-year results. The Journal of bone and joint surgery British volume. 2006;88(7):860-4. 53. Sochart DH, Porter ML. The long-term results of Charnley low-friction arthroplasty in young patients who have congenital dislocation, degenerative osteoarthrosis, or rheumatoid arthritis. J Bone Joint Surg Am. 1997;79(11):1599-617. 54. Sochart DH, Porter ML. Long-term results of cemented Charnley low-friction arthroplasty in patients aged less than 30 years. The Journal of arthroplasty. 1998;13(2):123-31. 55. Sullivan PM, MacKenzie JR, Callaghan JJ, Johnston RC. Total hip arthroplasty with cement in patients who are less than fifty years old. A sixteen to twenty-two-year follow-up study. J Bone Joint Surg Am. 1994;76(6):863-9. 56. Wroblewski BM, Siney PD, Fleming PA. Charnley low-frictional torque arthroplasty in young rheumatoid and juvenile rheumatoid arthritis: 292 hips followed for an average of 15 years. Acta orthopaedica. 2007;78(2):206-10. 57. Noordin S, Masri BA, Duncan CP, Garbuz DS. Acetabular bone loss in revision total hip arthroplasty: principles and techniques. Instructional course lectures. 2010;59:27-36. 58. D’Antonio JA, Capello WN, Borden LS, Bargar WL, Bierbaum BF, Boettcher WG, et al. Classification and management of acetabular abnormalities in total hip arthroplasty. Clinical orthopaedics and related research. 1989(243):126-37. 59. Dearborn JT, Harris WH. Acetabular revision arthroplasty using so-called jumbo cementless components: an average 7-year follow-up study. The Journal of arthroplasty. 2000;15(1):8-15. 60. Lachiewicz PF, Soileau ES. Fixation, survival, and dislocation of jumbo acetabular components in revision hip arthroplasty. J Bone Joint Surg Am. 2013;95(6):543-8. 61. Lian YY, Yoo MC, Pei FX, Kim KI, Chun SW, Cheng JQ. Cementless hemispheric acetabular component for acetabular revision arthroplasty: a 5- to 19-year follow-up study. The Journal of arthroplasty. 2008;23(3):376-82. 62. Hendricks KJ, Harris WH. Revision of failed acetabular components with use of so-called jumbo noncemented components. A concise follow-up of a previous report. J Bone Joint Surg Am. 2006;88(3):559-63.

26 CHAPTER 1

Introduction, general background and thesis outline

63. Moskal JT, Higgins ME, Shen J. Type III acetabular defect revision with bilobed components: five-year results. Clinical orthopaedics and related research. 2008;466(3):691-5. 1 64. Berry DJ, Sutherland CJ, Trousdale RT, Colwell CW, Jr., Chandler HP, Ayres D, et al. Bilobed oblong porous coated acetabular components in revision total hip arthroplasty. Clinical orthopaedics and related research. 2000(371):154-60. 65. Abeyta PN, Namba RS, Janku GV, Murray WR, Kim HT. Reconstruction of major segmental acetabular defects with an oblong-shaped cementless prosthesis: a long-term outcomes study. The Journal of arthroplasty. 2008;23(2):247-53. 66. Berry DJ. Antiprotrusio cages for acetabular revision. Clinical orthopaedics and related research. 2004(420):106-12. 67. Sembrano JN, Cheng EY. Acetabular cage survival and analysis of factors related to failure. Clinical orthopaedics and related research. 2008;466(7):1657-65. 68. Baauw M, van Hellemondt GG, Spruit M. A Custom-made Acetabular Implant for Paprosky Type 3 Defects. Orthopedics. 2016:1-4. 69. Shinar AA, Harris WH. Bulk structural autogenous grafts and allografts for reconstruction of the acetabulum in total hip arthroplasty. Sixteen-year-average follow-up. J Bone Joint Surg Am. 1997;79(2):159-68. 70. Siegmeth A, Duncan CP, Masri BA, Kim WY, Garbuz DS. Modular tantalum augments for acetabular defects in revision hip arthroplasty. Clinical orthopaedics and related research. 2009;467(1):199-205. 71. Hastings DE, Parker SM. Protrusio acetabuli in rheumatoid arthritis. Clinical orthopaedics and related research. 1975(108):76-83. 72. McCollum DE, Nunley JA, Harrelson JM. Bone-grafting in total hip replacement for acetabular protrusion. J Bone Joint Surg Am. 1980;62(7):1065-73. 73. Schimmel JW, Buma P, Versleyen D, Huiskes R, Slooff TJ. Acetabular reconstruction with impacted morselized cancellous allografts in cemented hip arthroplasty: a histological and biomechanical study on the goat. The Journal of arthroplasty. 1998;13(4):438-48. 74. Buma P, Lamerigts N, Schreurs BW, Gardeniers J, Versleyen D, Slooff TJ. Impacted graft incorporation after cemented acetabular revision. Histological evaluation in 8 patients. Acta orthopaedica Scandinavica. 1996;67(6):536-40. 75. van der Donk S, Buma P, Slooff TJ, Gardeniers JW, Schreurs BW. Incorporation of morselized bone grafts: a study of 24 acetabular biopsy specimens. Clinical orthopaedics and related research. 2002(396):131-41.

27 Cemented total hip arthroplasty and impaction bone grafting in young patients

76. Heekin RD, Engh CA, Vinh T. Morselized allograft in acetabular reconstruction. A 1 postmortem retrieval analysis. Clinical orthopaedics and related research. 1995(319):184-90. 77. Ullmark G. Bigger size and defatting of bone chips will increase cup stability. Archives of orthopaedic and trauma surgery. 2000;120(7-8):445-7. 78. Bolder SB, Schreurs BW, Verdonschot N, van Unen JM, Gardeniers JW, Slooff TJ. Particle size of bone graft and method of impaction affect initial stability of cemented cups: human cadaveric and synthetic pelvic specimen studies. Acta orthopaedica Scandinavica. 2003;74(6):652-7. 79. Busch VJ, Gardeniers JW, Verdonschot N, Slooff TJ, Schreurs BW. Acetabular reconstruction with impaction bone-grafting and a cemented cup in patients younger than fifty years old: a concise follow-up, at twenty to twenty-eight years, of a previous report. J Bone Joint Surg Am. 2011;93(4):367-71. 80. Schreurs BW, Busch VJ, Welten ML, Verdonschot N, Slooff TJ, Gardeniers JW. Acetabular reconstruction with impaction bone-grafting and a cemented cup in patients younger than fifty years old. J Bone Joint Surg Am. 2004;86-A(11):2385-92. 81. Schreurs BW, Gardeniers JW, Slooff TJ. Acetabular reconstruction with bone impaction grafting: 20 years of experience. Instructional course lectures. 2001;50:221-8. 82. Slooff TJ, Huiskes R, van Horn J, Lemmens AJ. Bone grafting in total hip replacement for acetabular protrusion. Acta orthopaedica Scandinavica. 1984;55(6):593-6.

28 CHAPTER 1

Introduction, general background and thesis outline

1

29

Hip resurfacing in patients under 55 years of age

Marloes W.J.L. Schmitz, René P.H. Veth,

B. Willem Schreurs

Nederlands Tijdschrift voor Geneeskunde 2011;155:A3186

CHAPTER 2 Cemented total hip arthroplasty and impaction bone grafting in young patients

ABSTRACT

Hip resurfacing arthroplasty was introduced as an alternative to the conventional 2 total hip arthroplasty which had shown suboptimal results in younger patients. Application of the resurfacing technique in younger patients has increased over the last few years. To date, no randomized controlled trials with a minimum follow- up span of 10 years comparing hip resurfacing to conventional hip replacement have been conducted in patients under 55 years of age. Australian and English hip registries demonstrate high revision rates after 5 years for some brands of resurfacing implants. In addition to these disappointing revision rates, the complication of aseptic lymphocytic vasculitis caused by metal particles evoking a local tissue reaction has been increasingly reported. The resurfacing procedure recently received some negative media attention in the Netherlands, leading to confusion among patients. In order to ease patient doubts, it is important to correctly inform them as to the type of implant used, for example, by means of the website or an information card.

32 CHAPTER 2

Hip resurfacing in patients under 55 years of age

In 2007 gaven wij in dit tijdschrift een overzicht van de beschikbare opties voor een heupprothese bij een jonge patiënt.1 Bij patiënten onder de 50 jaar werden destijds naast de gecementeerde en ongecementeerde conventionele totaleheupprothesen (THP), in toenemende mate ‘resurfacing’ prothesen gebruikt. Dit zijn heupprothesen die de kraakbeenoppervlakken vervangen, maar het oorspronkelijke bot zoveel mogelijk intact 2 laten (figuur 1). Ter vergelijking zijn in figuur 2 de onderdelen van een conventionele totaleheupprothese weergegeven.

FIGUUR 1. (a) Afbeelding van een ‘resurfacing’ prothese met een grote kopdiameter; (b) röntgenopname na plaatsing van deze resurfacing prothese (eerder gepubliceerde figuur).1

De resultaten op de korte termijn waren gunstig. Bij grote belasting ontstaan echter metaalpartikels ten gevolge van slijtage van deze metaal-op-metaalprothesen. Het was onduidelijk wat de langetermijngevolgen hiervan zouden zijn.2 Recent deed het Amerikaanse bedrijf DePuy Orthopaedics een officiële recall waarbij de resurfacing prothesen van deze firma van de markt werden gehaald wegens slechte resultaten. Ook heeft deze firma standaardheupprothesen die gebruik maakten van een metalen kop met grote diameter op een metalen kom (‘large head metal-on-metal’) van de markt genomen.

33 Cemented total hip arthroplasty and impaction bone grafting in young patients

2

FIGUUR 2. Schematische weergave van de onderdelen waaruit een totaleheupprothese (‘total hip’) bestaat

Deze berichtgeving leidt tot veel onduidelijkheid binnen zowel de medische wereld als onze jonge patiëntengroep, aangezien deze prothese ook in Nederland is toegepast. In dit artikel bespreken we daarom de huidige stand van zaken rond de resurfacing prothese bij jonge patiënten.

HET POTENTIËLE VOORDEEL VAN DE RESURFACING PROTHESE

Jonge patiënten gebruiken hun prothese intensiever dan ouderen, waardoor een grotere belasting van de prothese ontstaat, met als gevolg een snellere slijtage. Fixatie van de prothese is bij de jonge patiënt veelal lastiger, doordat zij vaak een onderliggende heupafwijking hebben waardoor de anatomie veranderd is. Gezien de levensverwachting van de jonge patiënten zal een groot deel van deze groep minstens eenmaal gedurende

34 CHAPTER 2

Hip resurfacing in patients under 55 years of age hun leven een revisie-operatie moeten ondergaan. Het is voor deze groep dus van extra belang een prothese te kiezen die gemakkelijk te reviseren is.

De resurfacing prothese werd geïntroduceerd als de prothese die makkelijker te reviseren zou zijn vanwege het botsparende effect. Bij de resurfacing prothese wordt over de 2 femurkop een metalen kap geplaatst, waardoor er minder femoraal bot hoeft te worden verwijderd. Bij een conventionele heupprothese wordt het collum met de heupkop gereseceerd. De huidige resurfacing prothese maakt gebruik van metaal-op-metaal- articulatie en heeft een ongecementeerde fixatie van het acetabulum en meestal een gecementeerde fixatie in het femur. De kop van deze systemen heeft een grote diameter, wat ertoe bijdraagt dat de kans op het uit de kom schieten van de resurfacing prothesen lager is dan bij een conventionele gecementeerde of ongecementeerde heupprothese. Bovendien werden na de operatie alle sporten toegestaan en zou de bewegingsuitslag groter zijn. Deze prothese werd populair onder de naam ‘sportheup’. In vergelijkende studies echter werd een grotere bewegingsuitslag niet bevestigd.3,4

RESULTATEN RESURFACING PROTHESE

Patiënten jonger dan 55 jaar Om de stand van zaken in beeld te brengen, hebben we gezocht naar studies gepubliceerd in de periode tot en met 31 december 2010, die de overleving van de resurfacing prothesen na minimaal 10 jaar of na gemiddeld 10 jaar beschreven. Daarbij was ons criterium dat de leeftijd van alle patiënten ten tijde van de operatie lager dan 55 jaar moest zijn. Net als in 2007 gebruikten wij als definitie voor een ‘goed resultaat’ dat 10 jaar na plaatsing meer dan 90% van de implantaten nog in situ was, conform de definitie van de NICE-2003- studiegroep.5 Voor het doorzoeken van Pubmed gebruikten wij de volgende zoekvraag: ((((((((resurfacing arthroplasty)) OR (metal-on-metal))) AND (hip OR hips))) AND (young OR adult* OR child* OR middle-age OR middle-aged OR adolescent*))) AND ((((cohort study)) OR (cohort analysis)) OR (follow-up study OR follow-up studies OR followup study OR followup studies)). Daarnaast hebben we de elektronische cochranedatabase en Web of Science doorzocht; hierbij maakten we gebruik van dezelfde zoektermen. De resultaten zijn weergegeven in figuur 3.

35 Cemented total hip arthroplasty and impaction bone grafting in young patients

602 artikelen gevonden Pubmed 367 Cochrane 23 Web of Science 212

2 geëxcludeerd: 11 studies in andere taal dan Engels, Frans, Duits of Nederlands 119 dubbele resultaten

472 artikelen gescreend op titel

geëxcludeerd: 225 studies waarin niet de overleving van resurfacing heupprothesen was bestudeerd

247 artikelen gescreend op abstract

geëxcludeerd: 207 studies 4 casusbeschrijvingen 1 commentaar op onderzoek 5 voldeden niet aan inclusiecriterium ‘leeftijd patiënt’ 103 voldeden niet aan inclusiecriterium ’10 jaar follow-up’ 94 betroffen niet het juiste onderwerp (bijvoorbeeld ander soort prothese, onjuist eindpunt)

40 artikelen volledig doorgenomen

geëxcludeerd: 40 studies die onjuiste eindpunten van de follow-up hadden of niet voldeden aan het leeftijdscriterium

0 artikelen geïncludeerd

FIGUUR 3. Schematische weergave van de resultaten van de zoekstrategie

Er waren geen studies met 10 jaar follow-up waarin alleen patiënten jonger dan 55 jaar waren geïncludeerd. Als aanvulling gebruikten we daarom de Australische en Engelse heupregisters. Deze bevatten weliswaar evenmin data met 10 jaar follow-up, maar hierin worden wel systematisch de resultaten voor de resurfacing prothese gedurende meerdere jaren vastgelegd. Uit die data blijkt dat met name vrouwen onder de 55 jaar een verhoogd

36 CHAPTER 2

Hip resurfacing in patients under 55 years of age risico op revisie hebben als zij een resurfacing prothese hebben gekregen (tabellen I en II).6,7 In het Australische heupregister waren nog geen gegevens bekend van 9 jaar follow- up na het plaatsen van de gecementeerde prothese bij patiënten jonger dan 55 jaar. Ook de uitkomsten van een RCT die de langetermijnresultaten bij jonge patiënten in beeld zal brengen, zijn nog niet beschikbaar.8 2 Tot slot hebben we gezocht naar Nederlandse cohortstudies over de resurfacing prothese bij patiënten jonger dan 55 jaar. Daarvan was er slechts 1 beschikbaar, met een follow-upduur van gemiddeld 9 jaar (uitersten: 1-16), waarin 114 resurfacing prothesen waren geïncludeerd. De resultaten lieten een 10-jaarsoverleving van de prothese tot aan revisie zien van 47% (95%-BI: 37-57).9 Dit betrof echter geen metaal-op-metaal- articulatie.

TABEL I. Cumulatieve percentages revisie-operaties na plaatsing van een heupprothese bij patiënten jonger dan 55 jaar (gegevens afkomstig uit het Australisch Heupregister) Type prothese Percentage revisie-operaties* (95% BI)

1 jaar na 3 jaar na 5 jaar na 7 jaar na 9 jaar na plaatsing plaatsing plaatsing plaatsing plaatsing Gecementeerde THP 1.1 (0.5-2.3) 2.3 (1.3- 4.0) 3.8 (2.4-6.0) 4.8 (3.1-7.4) Nog niet bekend

Ongecementeerde THP 1.4 (1.2-1.7) 3.1 (2.8-3.5) 3.9 (3.5-4.3) 4.7 (4.2-5.3) 5.7 (4.7-6.9)

Hybride THP 1.1 (0.7-1.6) 1.9 (1.4-2.6) 2.9 (2.1-3.8) 4.9 (3.7-6.4) 5.6 (4.2-7.3)

Resurfacing 1.5 (1.2-1.9) 2.7 (2.3-3.2) 4.1 (3.5-4.7) 5.6 (4.8-6.5) 7.1 (5.6-9.1)

THP = totale heupprothese *Revisiepercentage voor patiënten die ten tijde van de operatie < 55 jaar oud waren zoals weergegeven in het Australische heupregister. Het begrip ‘revisie’ omvat in dit register revisies van de femurcomponent (die bestaat uit een kop en een steel), de acetabulumcomponent, wissel van de kop en ‘insert’, revisie van beide componenten en revisie van alleen de kop.

37 Cemented total hip arthroplasty and impaction bone grafting in young patients

TABEL II. Cumulatieve percentages revisie-operaties na 3 en 5 jaar na plaatsing van een heupprothese bij mannelijke en vrouwelijke patiënten jonger dan 55 jaar (gegevens afkomstig uit het Engelse heupregister) Type prothese Aantal patiënten Percentage revisie-operaties* (95%-BI) 2 3 jaar na plaatsing 5 jaar na plaatsing Mannen

Gecementeerde THP 1.669 2.7 (1.9-3.8) 4.4 (3.2-6.0)

Ongecementeerde THP 3.858 2.9 (2.3-3.6) 4.0 (3.1-6.0)

Hybride THP 1.498 1.8 (1.2-2.7) 2.6 (1.7-3.8)

Resurfacing 4.215 3.6 (3.0-4.3) 5.6 (4.5-6.9)

LHMoM THP 1.564 4.5 (3.3-6.1) 6.4 (4.5-8.9)

Vrouwen

Gecementeerde THP 2174 2.5 (1.8-3.4) 3.6 (2.7-4.8)

Ongecementeerde THP 5082 2.7 (2.2-3.3) 4.3 (3.4-5.5)

Hybride THP 1840 2.2 (1.5-3.1) 4.0 (2.8-5.8)

Resurfacing 2647 5.4 (4.5-6.5) 8.3 (6.8-10.0)

LHMoM THP 1037 6.3 (4.6-8.6) 9.2 (5.9-14.1)

*Revisiepercentage voor patiënten die ten tijde van de operatie < 55 jaar oud waren zoals weergegeven in het Engelse heupregister. Het begrip ‘revisie’ omvat in dit register een re-operatie waarbij één of meer componenten van de prothese werd vervangen. Percentages zijn berekend met behulp van de overlevingsanalyse volgens Kaplan en Meier.

Patiënten van alle leeftijden Wanneer we nogmaals de heupregisters bekijken, maar dan voor alle leeftijden, blijkt uit het Australische heupregister dat de resurfacing prothese in het algemeen een hogere revisiegraad na 9 jaar heeft dan de THP, namelijk 7,2% versus 5,2%, bij de indicatie ‘a r t r o s e’. 6 Vrouwen boven de 65 jaar die een metaal-op-metaal resurfacing prothese ontvingen, hebben na 3 jaar al een 3-7 maal hogere kans op revisie dan vrouwen van dezelfde leeftijd die een conventionele THP ontvingen.6,10 Voor mannen onder de 55 jaar daarentegen is het revisiepercentage voor de resurfacing prothese vrijwel gelijk aan dat van een conventionele THP.6,10 Dit verschil is mogelijk ook gerelateerd aan de grootte van de kop, aangezien een kleinere kop, die vaak bij vrouwen geplaatst wordt, leidt tot een hoger risico op revisie. Voor patiënten van alle leeftijden laat het Engelse heupregister het laagste revisiepercentage na 5 jaar zien bij patiënten die een gecementeerde THP hadden

38 CHAPTER 2

Hip resurfacing in patients under 55 years of age gekregen, namelijk 2,0 % (95%-BI: 1,8-2,1).7 Voor een ongecementeerde THP was dit 2,7% (95%-BI: 2,4-3,0), voor een hybride prothese 3,4% (95%-BI: 3,2-3,7) en voor een resurfacing prothese 6,3% (95%-BI: 5,7-7,0).7 Het hoogste faalpercentage werd gezien na plaatsing van een metaal-op-metaal THP met een grote kop (‘large head metal-on-metal’ (LHMoM)), namelijk 7,8% (95%-BI: 6,6-9,3).7 Er zijn overigens grote verschillen in de 2 revisiepercentages tussen de verschillende merken resurfacing prothesen (tabel III).

TABEL III. Cumulatieve revisiepercentages 5 jaar na plaatsing van een resurfacing prothese, weergegeven per merk heupprothese Merk resurfacing prothese* Cumulatief revisiepercentage (95% BI)

ASR (DePuy Orthopaedics, Warsaw, VS) 10.9 (8.7-13.6)

BHR (Smith&Nephew, Warwick, VK) 3.5 (3.1-4.0)

Cormet (Corin, Cirencester, VK) 6.0 (3.5-10.2)

Durom (Zimmer, Warsaw, VS) 7.6 (5.7-10.0) *Alleen implantaten waarvan er jaarlijks meer dan 100 worden geplaatst en waarvan het cumulatieve percentage revisies na 5 jaar bekend was, zijn weergegeven. Gegevens zijn afkomstig uit het Australisch heupregister.6

REDENEN VOOR TEGENVALLENDE RESULTATEN

Allereerst blijkt de operatietechniek van de resurfacing prothese lastiger, omdat bij plaatsing van deze heupprothese collum en heupkop intact moeten blijven. De rol van de chirurg is hierbij belangrijk en de leercurve is vaak lang.11,12 Over het daadwerkelijke activiteitenniveau van de patiënt als factor die het resultaat bepaalt komen verschillende cijfers naar voren. Patiënten met een THP krijgen vaak het advies om niet overdreven actief te zijn, wat het beeld van de resultaten kan vertekenen.13 Uit een recente RCT bleek overigens dat het activiteitenniveau na plaatsing van een resurfacing prothese niet overduidelijk hoger was dan bij patiënten die een THP hadden gekregen.14

Complicaties Ook bij een resurfacing prothese kunnen luxaties optreden, al is de incidentie laag (0-1,8%).10 Naast de reeds bekende vroege complicaties van een resurfacing prothese,

39 Cemented total hip arthroplasty and impaction bone grafting in young patients

zoals de collumfractuur (incidentie: 0,4-6,0%),10 verschijnt een toenemend aantal artikelen die wijzen op het ontstaan van een andere complicatie. Het gaat hierbij om een wekedelenreactie op metaalionen die in de literatuur onder verschillende namen wordt beschreven, zoals ‘adverse reactions to metal debris’ (ARMD) en ‘pseudotumor’. 2 De histologische term is aseptische lymfocytaire vasculitis (ALVAL). De oorzaak van deze complicatie is waarschijnlijk in de meerderheid van de gevallen een stijging van de concentratie metaalionen tot een toxisch niveau. Deze hoge concentraties ontstaan door toegenomen slijtage, veelal bij malpositie.10,15 Een andere mogelijke hypothese stelt dat er langzaam metaalionen afgegeven worden door de prothesedragende oppervlakken als een soort bijproduct naast de normale slijtage. De slijtageproducten van metalen prothesen zijn aantoonbaar in de naastgelegen periprosthetische weke delen en op verder weg gelegen plekken zoals lymfeklieren, lever en milt. Deze slijtagepartikels vormen samen met lokale eiwitten haptenen, die een contactallergische reactie van het vertraagde type (type IV) opwekken in het lokale weefsel. De lokaal destructieve reactie kan lijden tot pijn, wekedelennecrose, osteolyse en loslating van de prothesecomponenten, waardoor revisie noodzakelijk is.15,16 De geschatte incidentie varieert van 1 tot 6,5%, maar verwacht wordt dat deze in de loop van de tijd toeneemt met een hoger aantal revisies als gevolg.15,17,18 Verder hebben veel patiënten een stijgende metaalspiegel in het serum waarvan de klinische relevantie nog niet duidelijk is.19 De revisie van een resurfacing prothese naar een conventionele THP wegens loslating van de femurcomponent of een collumfractuur is technisch goed uitvoerbaar en het resultaat komt overeen met dat van een primaire plaatsing van een conventionele THP. Wel worden bij deze patiënten veel luxaties gezien. Revisies wegens pseudotumoren zijn echter lastiger dan in eerste instantie werd gedacht en gaan gepaard met een hoog aantal re-revisies.20

TECHNISCHE ONTWIKKELINGEN EN HUIDIGE SITUATIE

In de jaren 60 en 70 van de vorige eeuw werden de eerste ontwerpen van metaal-op- polyethyleen en metaal-op-metaal resurfacing prothesen ontwikkeld. Deze vroege prothesen leden onder een inconsistente productie met wisselende resultaten. Het

40 CHAPTER 2

Hip resurfacing in patients under 55 years of age principe van metaal-op-metaal werd verdrongen door de steeds beter ontwikkelde gecementeerde THP. De metaal-op-polyethyleen resurfacing prothesen werden in de jaren 70 nog wel verder ontwikkeld, maar de gebruikte materialen waren te gevoelig voor slijtage. Het polyethyleen debris dat bij deze prothesen vrijkwam leidde tot osteolyse achter de kom. 2 Destijds werd osteolyse nog niet als dusdanig herkend en werden de waargenomen complicaties toegeschreven aan andere factoren, waaronder avasculaire necrose. Daarbij kwamen bij dit type prothese regelmatig collumfracturen voor.21 De tweede, huidige generatie resurfacing prothesen werd geïntroduceerd in 1996.22,23 Vanaf dat jaar ontstonden de resurfacing prothesen zoals ze tegenwoordig door verschillende fabrikanten worden geproduceerd. Deze resurfacing prothesen vertonen, zoals gezegd, onderling grote verschillen in overleving (zie tabel 3).6 De BHR (Smith & Nephew, Warwick, VK), ontwikkeld in 1996, heeft vanaf zijn introductie goede overlevingscijfers laten zien en vindt nog steeds toepassing in een geselecteerde patiëntengroep.24 Bij het recentelijk van de markt gehaalde ASR-systeem (DePuy Orthopaedics, Warsaw, VS) was het revisiepercentage na slechts 5 jaar follow-up 10,9% (95%-BI: 8,7-13,6). Om een beter inzicht te krijgen in de resultaten is de Nederlandse Orthopaedische Vereniging (NOV) per 1 april 2008 gestart met het landelijk implantaatregister ‘Landelijke Registratie Orthopedische Implantaten’ (LROI). Recent werd duidelijk dat vergelijkbare problemen als bij de metaal-op-metaal resurfacing prothesen ook spelen bij conventionele heupprothesen die gebruik maken van een metaal-op-metaal-articulatie met een grote kop (doorsnede ≥36 mm). Dit probleem lijkt zich echter niet voor te doen bij een kop met een doorsnede van 28 of 32 mm.25 Juist de metaal-op-metaal-articulatie met een grote kop werd echter de laatste jaren steeds populairder bij jonge patiënten. Er is nog veel onduidelijk, maar de taper van de steel van de conventionele heupprothese met metaal-op-metaal-articulatie met grote kop lijkt veel metaaldeeltjes te genereren. De productiewijze, vorm en positie van het implantaat bepalen in belangrijke mate de overleving van de heupprothese.26 Ook bij goed functionerende implantaten zijn echter problemen met metaalconcentraties gesignaleerd. Bij sommige patiënten waren te hoge metaalconcentraties op zich al de reden voor een revisie.

41 Cemented total hip arthroplasty and impaction bone grafting in young patients

Onzekerheid onder patiënten Het terugroepen van de ASR-prothese door de fabrikant heeft ook in ons land voor onrust gezorgd. De problemen met de resurfacing prothese zijn in de lekenpers breed uitgemeten en daarnaast weten patiënten vaak niet exact welk type prothese ze hebben. De NOV 2 ziet geen reden voor het terugroepen van de resurfacing prothese in het algemeen en de meer conventionele THP met grote metalen kop, maar adviseert patiënten wel zich op de hoogte te stellen van de huidige stand van zaken. Hierbij kan aan de patiënten worden uitgelegd dat met de huidige kennis een afwachtende houding gerechtvaardigd is als de patiënt geen pijn of andere klachten heeft. Een mogelijkheid tot gerichte controle dient echter wel te worden aangeboden. Door alleen patiënten aan te schrijven die een metaal-op-metaal THP hebben gehad, zijn er naar onze mening veel patiënten in Nederland in onzekerheid blijven rondlopen. Via websites van ziekenhuizen zou men bekend kunnen maken waar en in welke periode de metaal-op-metaal prothesen geplaatst zijn, om deze onrust weg te nemen. Ook de LROI kan daar aan bijdragen. Een preventieve maatregel om patiënten beter te informeren is het meegeven van kaartjes na een operatie met daarop het type prothese dat de patiënt gekregen heeft.

CONCLUSIE

Uit de voorgaande uiteenzetting blijkt dat de resurfacing prothese op een aantal punten niet aan de verwachtingen van een aantal jaar geleden voldoet. Het activiteitenniveau van de jonge patiënt die een resurfacing prothese heeft gekregen blijkt niet overduidelijk hoger te liggen dan na plaatsing van een THP. Wanneer we daarbij het aantal revisies en de complicaties door metaaldeeltjes in acht nemen wordt duidelijk dat de resurfacing prothese niet de oplossing is voor alle patiënten. Wel zijn er grote verschillen in uitkomst per merk. Bij de huidige stand van zaken blijkt de resurfacing prothese mogelijk wel geschikt voor met name jonge, actieve mannen. Daarnaast blijft de conventionele THP bestaan als optie voor de jonge patiënt; dit type prothese zorgt in het algemeen voor een grote toename in kwaliteit van leven. Onzekerheid bij patiënten over welk type prothese bij hen geplaatst is dient zo snel mogelijk te worden weggenomen. Dit geldt voor zowel de resurfacing prothese als de metaal-op-metaal THP met grote kop.

42 CHAPTER 2

Hip resurfacing in patients under 55 years of age

LEERPUNTEN

• De ‘resurfacing’ prothese is een veelgebruikte heupprothese bij patiënten jonger dan 55 jaar. • De voordelen van de resurfacing prothese zouden zijn dat deze botsparend is, een 2 hoog activiteitenniveau toe staat en makkelijk is te reviseren. • Op de korte termijn zijn de resultaten goed, maar er zijn grote verschillen tussen de diverse merken resurfacing prothesen in revisiepercentages op de middellangetermijn. • Een frequente complicatie is de ontstekingsreactie van weke delen door vrijgekomen metaaldeeltjes, resulterend in pijn, weefselverlies en osteolyse. • Recentelijk heeft de Amerikaanse firma DePuy Orthopaedics zijn resurfacing heupprothese teruggeroepen; de aandacht hiervoor in de lekenpers heeft tot veel onrust bij patiënten geleid.

43 Cemented total hip arthroplasty and impaction bone grafting in young patients

REFERENTIES

1. Schreurs BW, Busch VJ, Veth RP. Keuze voor een heupprothese voor patiënten jonger dan 50. Ned Tijdschr Geneeskd. 2007;151:1918-22 Medline.NTvG 2 2. MacDonald SJ. Metal-on-metal total hip arthroplasty: the concerns. Clin Orthop Relat Res. 2004;(429):86-93 Medline. doi:10.1097/01.blo.0000150309.48474.8b 3. Kluess D, Zietz C, Lindner T, Mittelmeier W, Schmitz K, Bader R. Limited range of motion of hip resurfacing arthroplasty due to unfavorable ratio of prosthetic head size and femoral neck diameter. Acta Orthop. 2008;79:748-54 Medline. doi:10.1080/17453670810016803 4. Incavo SJ, Thompson MT, Gold JE, Patel RV, Icenogle KD, Noble PC. Which procedure better restores intact hip range of motion; total hip arthroplasty or resurfacing? A combined cadaveric and computer simulation study. J Arthroplasty. 2011;26:391-7.Medline 5. National Institute for Clinical Excellence (NICE). Guidance on the selection of prostheses for primary total hip replacement. Londen: NICE; 2003. 6. Australian Orthopaedic Association National Joint Replacement Registry. Annual Report 2010. Adelaide:AOA; 2010. www.dmac.adelaide.edu.au/aoanjrr/documents/aoanjrrreport_2010. pdf. 7. National Joint Registry for England and Wales. Annual report 2010. NJR; 2010. www.njrcentre. org.uk/NjrCentre/LinkClick.aspx?fileticket=QkPI7kk6B2E%3d&tabid=86&mid=523 8. Achten J, Parsons NR, Edlin RP, Griffin DR, Costa ML. A randomised controlled trial of total hip arthroplasty versus resurfacing arthroplasty in the treatment of young patients with arthritis of the hip joint. BMC Musculoskelet Disord. 2010;11:8 Medline. doi:10.1186/1471- 2474-11-8 9. Duijsens A-WHB, Keizer S, Vliet-Vlieland T, Nelissen RGHH. Resurfacing hip prosthesis revisited. Failure analysis during a 16-year follow-up. Int Orthop. 2005;29:224-8 Medline. doi:10.1007/s00264-005-0652-8 10. Macpherson GJ, Breusch SJ. metal-on-metal hip resurfacing: a critical review. Arch Orthop Trauma Surg. 2011;131:101-10 Medline. doi:10.1007/s00402-010-1153-9 11. Witjes S, Smolders JM, Beaule PE, Pasker P, van Susante JL. Learning from the learning curve in total hip resurfacing: a radiographic analysis. Arch Orthop Trauma Surg. 2009;129:1293-9 Medline. doi:10.1007/s00402-009-0875-z

44 CHAPTER 2

Hip resurfacing in patients under 55 years of age

12. Kim PR, Beaule PE, Laflamme GY, Dunbar M. Causes of early failure in a multicenter clinical trial of hip resurfacing. J Arthroplasty. 2008;23(Suppl 1):44-9 Medline. doi:10.1016/j. arth.2008.05.022 13. van Gerwen M, Shaerf DA, Veen RM. Hip resurfacing arthroplasty. Acta Orthop. 2010;81:680- 3 Medline. doi:10.3109/17453674.2010.501742 2 14. Lavigne M, Therrien M, Nantel J, Roy A, Prince F, Vendittoli PA. The John Charnley Award: The functional outcome of hip resurfacing and large-head THA is the same: a randomized, double-blind study. Clin Orthop Relat Res. 2010;468:326-36 Medline. doi:10.1007/s11999- 009-0938-z 15. Pandit H, Glyn-Jones S, McLardy-Smith P, et al. Pseudotumours associated with metal-on- metal hip resurfacings. J Bone Joint Surg Br. 2008;90:847-51 Medline. doi:10.1302/0301- 620X.90B7.20213 16. Watters TS, Cardona DM, Menon KS, Vinson EN, Bolognesi MP, Dodd LG. Aseptic lymphocyte-dominated vasculitis-associated lesion: a clinicopathologic review of an underrecognized cause of prosthetic failure. Am J Clin Pathol. 2010;134:886-93 Medline. doi:10.1309/AJCPLTNEUAH8XI4W 17. Kwon YM, Ostlere SJ, McLardy-Smith P, Athanasou NA, Gill HS, Murray DW. “Asymptomatic” pseudotumors after metal-on-metal hip resurfacing arthroplasty prevalence and metal ion study. J Arthroplasty. 2011;26:511-8 Medline. 18. Glyn-Jones S, Pandit H, Kwon YM, Doll H, Gill HS, Murray DW. Risk factors for inflammatory pseudotumour formation following hip resurfacing. J Bone Joint Surg Br. 2009;91:1566-74 Medline. doi:10.1302/0301-620X.91B12.22287 19. deSouza RM, Parsons NR, Oni T, Dalton P, Costa M, Krikler S. Metal ion levels following resurfacing arthroplasty of the hip: serial results over a ten-year period. J Bone Joint Surg Br. 2010;92:1642-7 Medline. doi:10.1302/0301-620X.92B12.24654 20. Grammatopolous G, Pandit H, Kwon YM, et al. Hip resurfacings revised for inflammatory pseudotumour have a poor outcome. J Bone Joint Surg Br. 2009;91:1019-24 Medline. doi:10.1302/0301-620X.91B8.22562 21. Hodge WF, Fitts SM. Hip resurfacing. A fair and balanced review. Sem Arthroplasty. 2006;17:35-41. doi:10.1053/j.sart.2006.05.003 22. McMinn D, Treacy R, Lin K, Pynsent P. Metal on metal surface replacement of the hip. Experience of the McMinn prothesis. Clin Orthop Relat Res. 1996;(329 Suppl):S89-98 Medline. doi:10.1097/00003086-199608001-00009

45 Cemented total hip arthroplasty and impaction bone grafting in young patients

23. Wagner M, Wagner H. Preliminary results of uncemented metal on metal stemmed and resurfacing hip replacement arthroplasty. Clin Orthop Relat Res. 1996;(329 Suppl):S78-88 Medline. doi:10.1097/00003086-199608001-00008 24. McMinn DJ, Daniel J, Ziaee H, Pradhan C. Indications and results of hip resurfacing. Int 2 Orthop. 2011;35:231-7 Medline. doi:10.1007/s00264-010-1148-8 25. Girard J, Bocquet D, Autissier G, Fouilleron N, Fron D, Migaud H. Metal-on-metal hip arthroplasty in patients thirty years of age or younger. J Bone Joint Surg Am. 2010;92:2419-26 Medline. doi:10.2106/JBJS.I.01644 26. Zywiel MG, Sayeed SA, Johnson AJ, Schmalzried TP, Mont MA. Survival of hard-on-hard bearings in total hip arthroplasty: a systematic review. Clin Orthop Relat Res. 2011;469:1536- 46 Medline. doi:10.1007/s11999-010-1658-0

46 CHAPTER 2

Hip resurfacing in patients under 55 years of age

2

47

Long-term results of cemented total hip arthroplasty in patients younger than 30 years and the outcome of subsequent revisions

Marloes W.J.L. Schmitz, Vincent J.J.F. Busch,

Jean W.M. Gardeniers, Jan C.M. Hendriks,

René P.H. Veth, B. Willem Schreurs

BMC Musculoskeletal Disorders 2013 Jan 22;14:37

CHAPTER 3 Cemented total hip arthroplasty and impaction bone grafting in young patients

ABSTRACT

Background: The number of total hip arthroplasties in patients under 30 years is increasing over the years. Almost all of them will face at least one or more future revisions in their life. Therefore, the implant used should have a high survival rate, and needs to be easily revisable resulting in a low re-revision rate. Several studies 3 have evaluated the outcome of total hip arthroplasties in patients under 30 years. However, only a few reported on the follow-up outcome of 10 years or more. In addition, none of these reports published data of the subsequent revisions of these implants within their original report.

Methods: We studied historically prospective collected data of 48 consecutive patients (69 hips) younger than 30 years, treated with a cemented primary total hip prosthesis between 1988 and 2004. Since the last evaluation of this cohort, two patients were lost to follow-up. For all hip revisions in this cohort, again cemented implants were used, mostly in combination with bone impaction grafting. Kaplan- Meier survival curves at 10- and 15 years for the primary total hip arthroplasties and revisions were determined.

Results: The mean age at time of primary surgery was 25 years (range, 16 to 29 years). Mean follow-up of the primary hips was 11.5 years (range, 7 to 23 years). During follow-up 13 revisions were performed; in 3 cases a two-stage total revision was performed for septic loosening and 9 cups were revised for aseptic loosening. There were no aseptic stem revisions. The 10 and 15-year survival rates with endpoint revision for aseptic loosening of the primary total hip were 90% (95% confidence interval (CI): 79-96) and 82% (95% CI: 65-92) respectively. None of our 13 subsequent revisions needed a re-revision within 10 years after re-implantation.

Conclusions: Cemented total hip implants in patients under 30 years have an encouraging outcome at 10 and 15 years after surgery in these young patients. The 13 revised hips, treated with bone grafting and the third generation cement technique, were performing well with no re-revisions within ten years after surgery.

50 CHAPTER 3

Long-term results of cemented total hip arthroplasty in patients younger than 30 years and the outcome of subsequent revisions

BACKGROUND

The number of total hip arthroplasties in very young patients is rising. Different solutions to treat these young patients with secondary osteoarthritis have been used over the last decade. Non-cemented, cemented, hybrids, metal-on-metal total hip arthroplasties and resurfacing prostheses all have been used in young patients, with different success rates.1-22 Obviously, in these very young patients it is important to use total hip implants with a proven long-term outcome.23 Additionally, we have to keep in mind that these 3 young people will inevitably face one or more revisions in their life, due to their longer life expectancy. As a result, the implant used should have an acceptable and reliable long- term clinical outcome as it needs to be easy revisable without creating a bone stock defect. Both survival of the primary THA and subsequent revision THA are important outcome measurements in these young patients. So far, only a few reports present long-term results of total hip arthroplasties in patients under 30 years and none present the outcomes of the first revision THA’s in the same cohort (table I).

TABLE I. Characteristics and survivorship of THA in patients 30 years or younger at time of operation with a mean follow-up of more than ten years in literature up to March 2011 Study No hips No patients Mean age Mean Survivorship/revised in years follow-up hips for all reasons (range) in years (range) Cemented

Cage et al. 4 29 17* 18.4 (15-21) 10.6 (8-15) 1 revision at 11 yrs

Chmel et al. 7 66 39 19.9 (11-29) 15.1 (11-22) 70% at 15 yrs (acetabular revision) Sochart and 83 55 24.9 (17-29) 20 (5-30) 89% at 10 yrs ; 65% at Porter 8 25 yrs

Torchia et al. 6 63 50 17 (11-19) 12.6 (1.6-18.6) 27 revisions#

Witt et al. 3 96 54 16.7 (11-27) 11.5 (5-18) 24 (25%) at average 9.5 years follow-up

Wroblewski et 39 28 17.9 (12-19) 12.6 (2.3 – 29.0) for 16 revisions at mean 19.1 al. 18 non-revision yrs (8-34)

(current study) 69 48 24.6 (16-29) 11.3 (2-23.4) 86% at 10 yrs ; 75% at 15 yrs

Uncemented

Wangen et al. 16 49 44 25 (15-30) 13 (10-16) 24 revisions of acetabular component#

*mixed group of patients with total hip and total knee prosthesis #at mean follow-up

51 Cemented total hip arthroplasty and impaction bone grafting in young patients

Although cemented total hip implants are not commonly used in young patients, we have always used cemented total hip implants in all ages, including patients younger than thirty years. Furthermore, we have one essential addition in young patients: in case of substantial acetabular bone stock deficiencies, we have reconstructed this bone stock loss using impaction bone grafting (IBG). In these young patients, secondary osteoarthritis resulting from underlying diseases is often seen in combination with associated loss of the acetabular bone stock (e.g. in developmental dysplasia of the hips and juvenile 3 rheumatoid arthritis). This hampers an optimal insertion and fixation of the cup. We believe that IBG for the reconstruction of acetabular bone stock deficiencies in young patients is a biologically attractive approach, which restores bone stock already before the inevitable future revision.17 In all revisions we applied the same philosophy of using IBG on the acetabular side with a cemented cup. In case of femoral bone stock loss, femoral grafting was performed as well in order to achieve a durable reconstruction.24 The purpose of the current study is to present the clinical and radiographical results of 69 consecutive cemented total hip arthroplasties in 48 patients less than 30 years old after a mean follow up of more than 10 years, reporting the survival data with endpoint revision for any reason, aseptic loosing and radiological failure. In addition to the results of the primary total hip arthroplasties, the current state of our revisions and re-revisions within this group after the primary total hip arthroplasty will be assessed. Results will be compared to results of similar or other techniques found in the literature.

METHODS

In 2011, at a minimum follow-up of 7 years (7 to 23 years), we performed a historical prospective study on 48 consecutive patients (69 hips) younger than 30 years, who received a primary cemented total hip arthroplasty between April 1988 and May 2004. All indications except reconstructions for tumors were included. There was no selection bias as we used cemented total hips in all cases. The group consisted of 32 female (46 hips) and 16 male patients (23 hips). The mean age at surgery was 25 years (range, 16 to 29). Four patients (6 hips) died during follow-up of causes not related to their hip surgery. The mean age during surgery of these 4 patients was 24 years (range, 20 to 26). Their mean

52 CHAPTER 3

Long-term results of cemented total hip arthroplasty in patients younger than 30 years and the outcome of subsequent revisions follow-up until death was 9 years (range, 1 to 18). None of them was revised before death and all of them were followed up to their death on a regular base. Therefore, we included all their data. Two patients (3 hips) were lost to follow-up since our first evaluation of this cohort, including one patient with 2 THA’s after 3.5 years of follow-up of both hips and one patient with one THA after 11 years.17 Their data were included in the study up to their latest clinical and radiographic control. Table II lists the indications for the THA in all patients. 3 TABLE II. Indication for total hip arthroplasty (n=69) Indication Number of hips

Juvenile rheumatoid arthritis 18

Osteonecrosis of femoral head 21

Systemic lupus erythematosus 7

Acute lymphatic leukemia 3

Crohn’s disease 3

Nephropathy, kidney transplantation 2

Hypothalamic disorder 1

Aplastic anemia 1

Wegener’s disease 1

Unknown origin 3

Developmental dysplasia of the hip 7

Multiple epiphyseal dysplasia 2

Legg-Calvé-Perthes disease 6

Ankylosing spondylitis 5

Morquio’s disease 2

Ankylosis of unknown origin 2

Polycystic disease of the femoral head of unknown origin 2

Arthritis and osteomyelitits 2

Posttraumatic osteoarthritis 1

Psoriatic arthritis 1

In all cases, a posterolateral approach without a trochanteric osteotomy was used. Although we used different implants over the years, all of them were fully cemented (Table III). All cups were made of conventional polyethylene and only cobalt-chrome femoral heads of

53 Cemented total hip arthroplasty and impaction bone grafting in young patients

22 mm (9 hips), 28 mm (49 hips) and 32 mm (11 hips) were used. Up to 1990, all femoral components were inserted using a second-generation cementing technique, while from 1990 onwards the third cementing technique was used. Palacos cement was used until 1989 (Merck, Darmstadt, Germany); from 1989 on we used Surgical Simplex (Stryker- Howmedica, Newburry, UK). Antibiotics (cefazolin) were given during a maximum of 24 hours postoperatively to prevent infections.

3 TABLE III. Types of implant Type of acetabular implant Number of hips Type of femoral implant Number of hips

Müller®/Allopro® cup 14 M.E. Müller® straight stem 11

EliteTM Plus LPW 26 Charnley Elite (Plus) stemTM 13

Exeter/ContemporaryTM 29 Exeter StemTM 45

In case of bone stock deficiency during the primary procedure, we used the IBG technique to reconstruct acetabular defects (29 hips) (Figure 1 and 2). This technique has been described in the literature in detail before.17,25 Acetabular defects were classified according to the classification system of the American Academy of Orthopaedic Surgeons (AAOS) Committee on the Hip.26 In 5 hips a Type I defect was present. A Type II defect was seen in 16 hips and a Type III defect in 8 hips. In 23 hips, femoral head autografts were used, whereas fresh-frozen nonirradiated femoral head allografts were used as a source for bone chips in 3 hips with a Type III defect. In another 3 hips, both autografts and a fresh frozen allograft femoral head were used. Postoperatively, patients were treated with subcutaneous low-molecular-weight heparin for 6 weeks. Before 1999, oral anticoagulants were prescribed for 3 months according to our previous postoperative protocol. Indomethacin was administered for 7 days to prevent heterotopic ossification. Alternatively, one dose (7Gy) of radiotherapy was given, when indomethacin was contraindicated. Patients without a defect or a simple minor cavitary defect were mobilized under the supervision of a physiotherapist two days after surgery. In case of extended reconstructions, 10% touch weight bearing with crutches was allowed for 6 weeks, followed by 50% touch weight bearing for another 6 weeks, before full weight bearing was allowed. In case of very extensive acetabular reconstructions, e.g. severe pelvic dislocation and high dislocation, patients initially had a six-week period of bed rest to achieve full graft incorporation before starting mobilization.

54 CHAPTER 3

Long-term results of cemented total hip arthroplasty in patients younger than 30 years and the outcome of subsequent revisions

69 consecutive THA’s performed

pre-operative bone stock deficiency (n=29) no pre-operative bone stock deficiency (n=40) - Type I AAOS defect (n=5) - Type II AAOS defect (n=16) - Type III AAOS defect (n=8) 3

cemented THA and IBG (n=29) cemented THA without IBG (n=40)

FIGURE 1. In 29 of the 69 cases, a pre-operative bone stock deficiency on the acetabular side was present, which was classified according to the AAOS classification and treated with a cemented THA and IBG.

FIGURE 2. Acetabular reconstruction in a 27-year-old woman with secondary osteoarthritis due to congenital hip dysplasia. Preoperative (A), immediately postoperative (B), and 12 years postoperative (C).

The anteroposterior pelvic and lateral hip radiographs of all hips were analysed on a consensus basis by two of the authors (MWJLS and BWS). Follow-up radiographs were complete for all hips, except for the two patients lost to follow-up. Graft incorporation was determined as the manifestation of a regular radiodensity and trabecular bone structure throughout the graft and host bone with a continuous trabecular pattern according to Conn et al.27 Radiolucent lines were described if they were more than 2 mm wide and

55 Cemented total hip arthroplasty and impaction bone grafting in young patients

were defined as stable or as progressive lines in time. The criteria of DeLee and Charnley were used to identify acetabular zones.28 Radiographic failure was defined as radiolucent lines in all three zones and/or migration of 5 mm or more in any direction on the AP- pelvic view relative to the interteardrop line. The classification of Brooker et al. was used to describe heterotopic ossification29 . Polyethylene wear was calculated using the method of Dorr and Wan.30 On the femoral side, the Gruen classification was used to determine radiolucent zones.31 Femoral prosthetic subsidence was considered if it was more than 2 3 mm32 while definite loosening of the stem was defined as the appearance of a radiolucent line in all Gruen zones that did not exist on the immediate postoperative radiographs, or as a crack in the cement or fracture of the stem.33 The Harris Hip Score and Oxford Hip Score were determined at each follow-up visit to evaluate clinical results, as were the VAS scores (on a scale of 1 to 100) for pain during rest and activity as well as the VAS score for satisfaction about the hip function (on a scale of 1 to 100). Cemented total hip arthroplasties with acetabular IBG were used in al revision procedures. In case of femoral bone deficiency, we performed femoral IBG.34 For this study, no ethical approval was required by the local ethical committee.

Statistical analysis Kaplan-Meier survival analysis were used to determine the survivorship of the primary hip implant for the endpoints revision of one or both components for 1) any reason, 2) aseptic loosening and 3) radiographic failure. In addition to analysis for the total group, hips with and without acetabular IBG were also analysed separately. The HHS and OHQS were evaluated in 3 categories: 1) after 2 to 5 years follow-up, 2) after 5 to 10 years follow- up and 3) after more than 10 years follow-up. A ‘last observation carried forward analysis’ was done to determine the mean HHS and OHQS scores for the total group of surviving hips. VAS scores regarding pain in rest, pain during activity and overall satisfaction were determined. In addition to the results of our primary total hip arthroplasties, a Kaplan- Meier survival analysis was performed for the revisions in our group. HHS and OHQS, as well as VAS-scores were also calculated for the revised total hip arthroplasties. All calculations were made with SPSS 18.0.2 and SAS for Windows 9.2.

56 CHAPTER 3

Long-term results of cemented total hip arthroplasty in patients younger than 30 years and the outcome of subsequent revisions

RESULTS

Clinical results Mean duration of follow-up of all 69 primary total hips was 11.5 years (range, 7 to 23 years). During follow-up, 5 patients died (7 hips), two patients were lost to follow-up (3 hips) and 13 hips were revised for several reasons. The average pre-operative HHS score was 47.0 (range 15 to 81) (n=30), and the average pre-operative OHQS was 43.2 (range 34 to 52) (n=9). At review the mean HHS of the 49 surviving hips was 88.3 (n=48) (range 3 55 to 100) and the mean OHQS was 17.5 (range, 12 to 34) (n=49) after a mean follow-up of 11.6 (range 3.0 to 22.0). The mean VAS score for pain in rest and during activity on a scale from 0-100 after a mean follow-up of twelve years were 5.5 and 16.0, respectively. VAS score for overall satisfaction was 88.8.

Revisions and complications Three total revisions for septic loosening were performed at 4.8, 5.7 and 6.1 years after the index surgery. All were treated with a two stage treatment protocol and all components were exchanged. One patient, originally planned for a one-stage cup revision after 13 years for aseptic loosening had positive cultures at revision, suggesting septic loosening. This patient was treated during 3 months with antibiotics and despite partial revision, no relapse occurred. Nine cups had been revised because of aseptic loosening at 2.3, 3.0, 4.1, 4.9, 7.6, 8.6, 13.6, 14.3 and 23.6 years. Except for the three stems revised for septic loosening, no additional stems had failed. One highly polished stem had to be exchanged for a same size stem using the cement in cement technique during a cup revision due to damage to the taper caused during that cup revision. This case was scored as a re- operation but this stem exchange is not considered as a stem failure. In addition to these revisions mentioned, one early re-operation after a primary THA was necessary due to a suspected infection. The patient recovered after débridement and antibiotic therapy without implant revision. Two early dislocations were seen. In one case an open reduction was needed. One partial femoral nerve deficit was seen, and despite surgical release, recovery was incomplete. One periprosthetic fracture, type Vancouver B1 occurred, fifteen years after the primary surgery for which open reduction and internal fixation was necessary without exchange of the implant. Other complications and their outcomes are listed in Table IV.

57 Cemented total hip arthroplasty and impaction bone grafting in young patients

TABLE IV. Complications of the 69 primary total hip arthroplasties, excluding the 13 revisions. Complications N Outcome

Early reoperation due to suspicion of deep infection 1 Fully recovered

Dislocation 2 One successful closed reduction, however one disloca- tion in a multi trauma patient needed surgical reduction

Neurological deficit 1 Femoral nerve exploration; incomplete recovery

Periprosthetic Fracture Vancouver B1 1 Plate osteosynthesis with cable grip plate system. No 3 revision of the implant

Radiographic results Radiolucent lines around the cup were observed in 18 of the 56 surviving hips, which were progressive in 6 hips. Osteolysis was seen in different zones on the acetabular side as well as on the femoral side. The complete detailed radiographic characteristics found in the 56 non-revised total hip arthroplasties are shown in Table V.

Survivorship analysis Regarding the endpoint revision for any reason of both cup and stem, the 10-year survival rate for the primary total group was 86% (95% CI: 74 - 92) and the 15-year survival rate was 75% (95% CI: 59 - 86) (Table VI). For endpoint revision for aseptic loosening, the 10- and 15-year survival rates for the total group were 90% (95% CI: 79 - 96) and 82% (95% CI: 65 - 92), respectively (Table VI and Figure 3). Of the 9 revisions for aseptic loosening, 7 were primary cemented hips without IBG while there were only 2 revisions in the IBG group. The 15-year survival rate for the primary cemented hips was 80% (95% CI: 60 - 91) for endpoint aseptic loosening, whereas this was 86% (95% CI: 48 - 97) for the total hips that were combined with IBG group. This was not statistically different (p = 0.30). Survival curves for each type of implant separately did not show any significant differences.

58 CHAPTER 3

Long-term results of cemented total hip arthroplasty in patients younger than 30 years and the outcome of subsequent revisions

TABLE V. Radiographic characteristics of 56 primary total hip arthroplasty patients that were not revised at last follow-up Radiographic characteristics

Acetabular radiolucent lines 18 Progressive 6

Stable 12 Osteolysis 9

Zone I 3 3

Zone II 3

Zone III 2

Zone I+II 1

Socket migration -

Progressive tilting of the cup -

PAO’s 13

Brooker class II 9

Brooker class III 4

Polyethylene wear > 2 mm 3

Femoral radiolucent lines 3

Zone 7 1

Zone 3 and 5 1

6 out of 7 zones 1

Rounding off of the calcar 8

Cortical atrophy 2

Zone 4 1

Zone 7 1

Cortical hypertrophy 5

Zone 3 1

Zone 4 3

Zone 5 1

Osteolysis of femoral component 7

Zone 1 1

Zone 4 1

Zone 5 1

Zone 7 1

Zone 1 and 7 4

Note: multiple radiographic characteristics per patient are possible

59 Cemented total hip arthroplasty and impaction bone grafting in young patients

TABLE VI. The 10-year and 15-years survivorship with the 95% confidence intervals (CI) for the three endpoints (revision for any reason, revision for aseptic loosening, radiographic failure) of the 69 hips including 29 total hip arthroplasties with impaction bone grafting (IBG) and 40 primary cemented total hip arthroplasties Category of patients Proportion revision Proportion revisions Proportion free of free for any reason free for aseptic radiographic failure loosening

10-year 15-year 10-year 15-year 10-year 15-year (95% CI) (95% CI) (95% CI) (95% CI) (95% CI) (95% CI) 3 All hips (n=69) 86% 75% 90% 82% 90% 82% (74 to 92) (59 to 86) (79 to 96) (65 to 92) (80 to 96) (65 to 92)

Primary cemented hips (n=40) 81% 71% 86% 80% 86% 80% (64 to 91) (50 to 84) (70 to 94) (60 to 91) (70 to 94) (60 to 91)

Acetabular IBG (n=29) 93% 83% 96% 86% 96% 86% (74 to 98) (49 to 95) (77 to 99) (48 to 97) (77 to 99) (48 to 97)

FIGURE 3. Kaplan Meier estimated survival of the total of sixty-nine hips regarding endpoint revision for aseptic loosening.

Outcome of the thirteen revisions All 13 failed primary hips were revised in our institution and the reasons for revision have been explained previously. In all 3 septic loosenings, acetabular bone impaction grafting and a cemented implant was used in the second stage. Additionally, in 2 of the stem

60 CHAPTER 3

Long-term results of cemented total hip arthroplasty in patients younger than 30 years and the outcome of subsequent revisions revisions femoral bone impaction grafting was used. No relapse of infection occurred. In the 9 isolated cup revisions, acetabular bone impaction was used in combination with a cemented cup. In one case the new cup was simply re-cemented. The 12 defects seen on the acetabular side were five segmental defects (AAOS type I), two cavitary defects (AAOS type II) and five combined defects (AAOS type III). All of the segmental defects were reconstructed using a wire mesh. Of the cavitary defects, one did not need any mesh while the other was reconstructed with a medial and a rim mesh. Of the combined defects, 2 received only a rim mesh and three received both a rim and a medial mesh. 3 The mean follow-up of the 13 revisions after the surgery was seven years (range, 1 to 15 years). Remarkably, the only re-revision in this study was performed 13 years after cup revision without acetabular bone impaction grafting. One patient had a partial lesion of the femoral nerve after a cup revision, which recovered partially without any invasive treatment. Of the twelve non re-revised cups, we collected the postoperative HHS and OHQS after a mean follow-up of 7 years (range, 0.5 to fifteen years), which were 82.7 (range 49 to 100) and 22.3 (range 12 to 52), respectively. Further analysis of these scores revealed that two patients had strikingly disappointing HHS and OHQS scores. One of the patients has a history of sclerodermia, M. Crohn, and recently received a stoma. The second patient post-operatively experienced problems of the femoral nerve which influences his activity and pain scores. This explains the differences of the HHS and OHQS scores between the primary and revision total hip arthroplasties. VAS scores of the twelve patients after revision for pain during rest and activity were 11.7 (range, 0-80) and 36.7 (range, 0 to 100), respectively. The mean VAS satisfaction score was 68.3 (0 to 100). The Kaplan Meier survival curve of our revisions with endpoint revision for any reason showed a 100% survival at 10 years.

DISCUSSION

Very young patients with osteoarthritis of the hip are still a challenge for orthopaedic surgeons. Frequently, due to the underlying pathology, an acetabular bone stock deficiency in this group is seen. Often large sized cups are used in order to cover this defect, without restoring the bone stock. However, in these younger THA patients, future

61 Cemented total hip arthroplasty and impaction bone grafting in young patients

revisions will be inevitable. It is therefore of extreme importance to create an optimal bone stock situation in order to prepare future (re)-revisions. We have described both the technique and outcome of the reconstruction of acetabular defects with IBG in young patients up to the age of 50 before.25, 35, 36 Although it is not very common in young patients, we have always used cemented total hip arthroplasties and cemented revisions in this young population. Furthermore, we used bone grafts in all cases with bone stock loss, thereby facilitating a biological 3 reconstruction. Our 10 year Kaplan Meier estimated survival for endpoint aseptic loosening of 90% (95% CI: 79 to 96) is within the NICE criteria.37 Our 15 year estimated survival of 82% is still acceptable in these very young patients but needs to be monitored closely over the next years. At review of the literature in March 2011, there was only limited literature available regarding the survival and complications of a total hip arthroplasty after a mean follow-up of 10 years or more in patients under 30 years. None of the reports included the outcome of their revisions in the same report as well. It should be noted that for young patients both outcome of the primary and revision THA, are equally important. Moreover, we assume that the outcome of the revision THA can be influenced by the primary THA procedure. Our results are at least comparable to the cohorts treated with a cemented THA, mentioned in table 1. Compared to the studies reporting on cohorts of the same size there seems to be a trend that the survival rates we obtain by using the biological IBG technique are more favourable, as can be seen in table 1. For the non-cemented total hip arthroplasty, only Wangen et al.16 reported the survival rates in patients less than 30 years old after a mean follow-up of more than 10 years. They reported 24 acetabular revisions in 49 hips at a mean follow-up of 13 years. McCullough et al. reported the survival rates in patients with a mean age of 24 years (range, 11 to 35) and showed a survival rate for the THA of 71% at 13 years.13 Both these studies do not equal our satisfying long-term survival rates. Over time, other techniques like the resurfacing prosthesis and large head metal-on-metal THA, have been introduced to treat young people with osteoarthritis. Unfortunately, the resurfacing prosthesis has shown its limitations, even before a large number of long-term follow-up studies were finished.38 A higher revision risk for younger female patients is observed, possibly related to their lower neck-head ratio, restricting the indications to younger males.39 Furthermore, the formation of pseudotumors and elevated ion levels which have been described for large head Metal-on-Metal THA as well, cause limitations to the application of these types of arthroplasties.40

62 CHAPTER 3

Long-term results of cemented total hip arthroplasty in patients younger than 30 years and the outcome of subsequent revisions

The study of Girard et al. shows a very acceptable 10-year survival rate of 94.5% (95% CI: 80 - 98.6) for the non-cemented total hip arthroplasty with metal-on-metal bearings in patients younger than 30 years at time of surgery, but includes only 28 mm heads.22 In our study we observed 13 revisions. Reasons for failure, in addition to the 4 septic revisions (3 complete revisions and one cup revision), are speculative and probably multifactorial. Two of our aseptic failures experienced a fall that could have caused accelerated loosening. One cup that was part of a total hip arthroplasty revision for septic loosening performed 3 thirteen years earlier was re-revised. All other twelve revised hips were reconstructed on the acetabular side with IBG. All of them are still in situ and none of them show radiographic loosening. No femoral revisions for aseptic loosening were performed, emphasizing the good results of the cemented femoral component in this specific young population. The 100% survival of our revisions at ten-year follow-up is a promising result for young people. The outcome of the primary prosthesis and the subsequent revision outcome are equally important to determine the best solution in young patients. IBG was associated with attractive survival results both in primary THA and revisions. Of the 9 primary total hip arthroplasties that needed a revision for aseptic loosening, only 2 had received IBG. The results as shown in table 5 clearly outpoint a trend that IBG shows better results compared to non-IBG. Even after 15 years of follow-up, the survival rate for endpoint revision for any reason is still 83% (95% CI: 49 - 95) and for aseptic loosening even 86% (CI: 48 - 97). The number of hips in this study is acceptable regarding the longterm follow-up. In addition, the outcome of all revisions is known. In all patients, the same philosophy was used. As a referral centre we have included all indications except oncologic cases, which makes this an unique cohort. However, this study has some limitations. First, two patients were lost to follow-up. Often patients lost to follow-up are presented as censored cases. But as described by Murray, this might underestimate the revision rate.41 Secondly, several different implants are used in our relatively small group of patients, however, all were cemented and all patients were treated in the same way according to our protocol. Survival curves for each type of implant separately showed no significant differences, and two of the components are still widely used (Exeter and Müller, Table 2).42 Furthermore, when reporting on surgery performed over a period of time, the use of different implants is almost inevitable. One can argue that 26 of our patients were

63 Cemented total hip arthroplasty and impaction bone grafting in young patients

treated for rheumatic diseases and therefore may be low-demand patients. However, most series on hip arthroplasty outcome in very young patients include a significant number of patients with rheumatic disease. Lastly, it would be interesting to have more information about the activity level of all patients in addition to the collected HHS, OHS and VAS scores, as these scores might not completely satisfactorily describe level and duration for sport activity etc. In addition, as this study is performed in a consecutive series of 69 THA’s performed in the period 1988-2004 it is not possible to retrospectively collect more 3 information about the difference in pre- and postoperative activity level.

CONCLUSIONS

The 10- and 15 year survival rates for endpoint aseptic loosening of cemented total hip arthroplasty in patients younger than 30 years are promising and indicate that this is a satisfying option for young people suffering of degenerative cartilage disease. IBG can be used to reconstruct the acetabular bone deficiency in primary as well as revision total hip arthroplasty. In our cohort none of the subsequent revisions was revised within 10 years. Particularly for young patients, reporting the survival of primary total hip arthroplasties and reporting the survival results of the revisions of the same cohort are equally important.

64 CHAPTER 3

Long-term results of cemented total hip arthroplasty in patients younger than 30 years and the outcome of subsequent revisions

REFERENCES

1. Halley DK, Charnley J. Results of low friction arthroplasty in patients thirty years of age or younger. Clin Orthop Relat Res. 1975 112:180-91. 2. Chandler HP, Reineck FT, Wixson RL, McCarthy JC. Total hip replacement in patients younger than thirty years old. A five-year follow-up study. J Bone Joint Surg Am. 1981 63(9):1426-34. 3. Witt JD, Swann M, Ansell BM. Total hip replacement for juvenile chronic arthritis. J Bone Joint Surg Br. 1991 73(5):770-3. 3 4. Cage DJ, Granberry WM, Tullos HS. Long-term results of total arthroplasty in adolescents with debilitating polyarthropathy. Clin Orthop Relat Res. 1992 283:156-62. 5. Maric Z, Haynes RJ. Total hip arthroplasty in juvenile rheumatoid arthritis. Clin Orthop Relat Res. 1993 290:197-9. 6. Torchia ME, Klassen RA, Bianco AJ. Total hip arthroplasty with cement in patients less than twenty years old. Long-term results. J Bone Joint Surg Am. 1996 78(7):995-1003. 7. Chmell MJ, Scott RD, Thomas WH, Sledge CB. Total hip arthroplasty with cement for juvenile rheumatoid arthritis. Results at a minimum of ten years in patients less than thirty years old. J Bone Joint Surg Am. 1997 79(1):44-52. 8. Sochart DH, Porter ML. Long-term results of cemented Charnley low-friction arthroplasty in patients aged less than 30 years. J Arthroplasty. 1998 13(2):123-31. 9. Kumar MN, Swann M. Uncemented total hip arthroplasty in young patients with juvenile chronic arthritis. Ann R Coll Surg Engl. 1998 80(3):203-9. 10. Haber D, Goodman SB. Total hip arthroplasty in juvenile chronic arthritis: a consecutive series. J Arthroplasty. 1998 13(3):259-65. 11. Lebel E, Itzchaki M, Hadas-Halpern I, Zimran A, Elstein D. Outcome of total hip arthroplasty in patients with Gaucher disease. J Arthroplasty. 2001 16(1):7-12. 12. Odent T, Journeau P, Prieur AM, Touzet P, Pouliquen JC, Glorion C. Cementless hip arthroplasty in juvenile idiopathic arthritis. J Pediatr Orthop. 2005 25(4):465-70. 13. McCullough CJ, Remedios D, Tytherleigh-Strong G, Hua J, Walker PS. The use of hydroxyapatite-coated CAD-CAM femoral components in adolescents and young adults with inflammatory polyarthropathy: ten-year results. J Bone Joint Surg Br. 2006 88(7):860-4. 14. Kitsoulis PB, Stafilas KS, Siamopoulou A, Soucacos PN, Xenakis TA. Total hip arthroplasty in children with juvenile chronic arthritis: long-term results. J Pediatr Orthop. 2006 26(1):8-12. 15. Nizard R, Pourreyron D, Raould A, Hannouche D, Sedel L. Alumina-on-alumina hip arthroplasty in patients younger than 30 years old. Clin Orthop Relat Res. 2008 466(2):317-23.

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16. Wangen H, Lereim P, Holm I, Gunderson R, Reikeras O. Hip arthroplasty in patients younger than 30 years: excellent ten to 16-year follow-up results with a HA-coated stem. Int Orthop. 2008 32(2):203-8. 17. Busch V, Klarenbeek R, Slooff T, Schreurs BW, Gardeniers J. Cemented hip designs are a reasonable option in young patients. Clin Orthop Relat Res. 2010 468(12):3214-20. 18. Wroblewski BM, Purbach B, Siney PD, Fleming PA. Charnley low-friction arthroplasty in teenage patients: the ultimate challenge. J Bone Joint Surg Br. 2010 92(4):486-8. 3 19. Clohisy JC, Oryhon JM, Seyler TM, Wells CW, Liu SS, Callaghan JJ, et al. Function and fixation of total hip arthroplasty in patients 25 years of age or younger. Clin Orthop Relat Res. 2010 468(12):3207-13. 20. Raphael BS, Dines JS, Akerman M, Root L. Long-term followup of total hip arthroplasty in patients with cerebral palsy. Clin Orthop Relat Res. 2010 468(7):1845-54. 21. Simon JP, Maes M, Robbens E, Bellemans J. Total hip arthroplasty in inflammatory arthritis in patients under 35 years. A 7 to 19 year follow-up. Hip Int. 2010 20(2):163-70. 22. Girard J, Bocquet D, Autissier G, Fouilleron N, Fron D, Migaud H. Metal-on-metal hip arthroplasty in patients thirty years of age or younger. J Bone Joint Surg Am. 2010 92(14):2419- 26. 23. McAuley JP, Szuszczewicz ES, Young A, Engh CA, Sr. Total hip arthroplasty in patients 50 years and younger. Clin Orthop Relat Res. 2004 418:119-25. 24. Gie GA, Linder L, Ling RSM, Slooff TJJH, Timperley AJ. Impacted cancellous allografts and cement for revision total hip arthroplasty. J Bone soint Surg 1993 75-B:14-21 25. Schreurs BW, Slooff TJ, Gardeniers JW, Buma P. Acetabular reconstruction with bone impaction grafting and a cemented cup: 20 years’ experience. Clin Orthop Relat Res. 2001 393:202-15. 26. D’Antonio JA, Capello WN, Borden LS, Bargar WL, Bierbaum BF, Boettcher WG, et al. Classification and management of acetabular abnormalities in total hip arthroplasty. Clin Orthop Relat Res. 1989 243:126-37. 27. Conn RA PL, Stuaffer RN, Ilstrup D. Management of acetabular deficiency; long-term results of bone-grafting the acetabulum in total hip arthroplasty. Orthop Trans. 1985. 28. DeLee JG, Charnley J. Radiological demarcation of cemented sockets in total hip replacement. Clin Orthop Relat Res. 1976 121:20-32. 29. Brooker AF, Bowerman JW, Robinson RA, Riley LH, Jr. Ectopic ossification following total hip replacement. Incidence and a method of classification. J Bone Joint Surg Am. 1973 55(8):1629- 32.

66 CHAPTER 3

Long-term results of cemented total hip arthroplasty in patients younger than 30 years and the outcome of subsequent revisions

30. Dorr LD, Wan Z. Comparative results of a distal modular sleeve, circumferential coating, and stiffness relief using the Anatomic Porous Replacement II. J Arthroplasty. 1996 11(4):419-28. 31. Gruen TA, McNeice GM, Amstutz HC. “Modes of failure” of cemented stem-type femoral components: a radiographic analysis of loosening. Clin Orthop Relat Res. 1979 141:17-27. 32. Loudon JR, Older MW. Subsidence of the femoral component related to long-term outcome of hip replacement. J Bone Joint Surg Br. 1989 71(4):624-8. 33. Harris WH, McCarthy JC, Jr., O’Neill DA. Femoral component loosening using contemporary techniques of femoral cement fixation. J Bone Joint Surg Am. 1982 64(7):1063-7. 3 34. Schreurs BW, Arts JJ, Verdonschot N, Buma P, Slooff TJ, Gardeniers JW. Femoral component revision with use of impaction bone-grafting and a cemented polished stem. Surgical technique. J Bone Joint Surg Am. 2006 88 Suppl 1 Pt 2:259-74. 35. Busch VJ, Gardeniers JW, Verdonschot N, Slooff TJ, Schreurs BW. Acetabular reconstruction with impaction bone-grafting and a cemented cup in patients younger than fifty years old: a concise follow-up, at twenty to twenty-eight years, of a previous report. The Journal of bone and joint surgery. [Research Support, Non-U.S. Gov’t]. 2011 16;93(4):367-71. 36. de Kam DC, Gardeniers JW, Hendriks JC, Veth RP, Schreurs BW. Cemented polyethylene cups in patients younger than 40 years. Clinical orthopaedics and related research. 2009 467(7):1753-64. 37. National Institute for Clinical Excellence (NICE). Guidance on the selection of prostheses for primary total hip replacement. Londen: NICE; 2003. 38. Macpherson GJ, Breusch SJ. Metal-on-metal hip resurfacing: a critical review. Arch Orthop Trauma Surg. 2011 131(1):101-10. 39. Australian Orthopaedic Association, National Joint Replacement Registry, Annual Report 2011 available at http://www.dmac.adelaide.edu.au/aoanjrr/documents/AnnualReports2011/ AnnualReport_2011_WebVersion.pdf (accessed December 2012) 40. Smith AJ, Dieppe P, Howard PW, Blom AW, National Joint Registry for England and Wales. Failure rates of metal-on-metal hip resurfacings: analysis of data from the National Joint Registry for England and Wales. Lancet. 2012 17;380(9855)v:1759-66. 41. Murray DW, Britton AR, Bulstrode CJ. Loss to follow-up matters. J Bone Joint Surg Br. 1997 79(2):254-7. 42. Swedish Hip Arthroplasty Register, Annual Report 2009. Available at http://www.shpr.se/ Libraries/Documents/AnnualReport-2009-EN.sflb.ashx, Accessed February 1, 2012.

67

Results of the cemented Exeter femoral component in patients under 40 years of age An update at 10 to 20 years follow-up

Marloes W.J.L. Schmitz, Eelco Bronsema,

Daniël C.J. de Kam, Jean W.M. Gardeniers,

René P.H. Veth, B. Willem Schreurs

Bone and Joint Journal 2017 feb;99-B(2):192-198

CHAPTER 4 Cemented total hip arthroplasty and impaction bone grafting in young patients

ABSTRACT

Aims: This study was performed to update the long term results of the cemented Exeter stem in patients under 40 years at a mean follow-up of 13.6 years (10 – 20 years).

Methods: We included our original cohort of 104 cemented Exeter stems in 78 consecutive patients with a mean age of 31 years (16 to 39). One patient was radiographically lost to follow-up. 4 Results: Six patients (eight hips) had died, none were related to their surgery. In addition to our earlier results, one traumatic periprosthetic fracture after a fall occurred and one stem broke. No revisions for aseptic loosening were performed during the whole study period, but 11 stems showed progressive radiolucent lines in one or more zones. The Kaplan Meier survival with endpoint revision for any reasons at 10 and 17 years was 97.1% (95% CI: 91.3-99.1) and 92.1% (95% CI: 74.1- 97.8), and 100% for aseptic loosening (95% CI: 83.8-100) both at 10 and 17 years. No additional stem was classified as radiographically loose.

Conclusions: The clinical and radiographical results of the Exeter stem in young patients are satisfying up to 17 years after surgery.

70 CHAPTER 4

Results of the cemented Exeter femoral component in patients under 40 years of age. An update at 10 to 20 years follow-up.

INTRODUCTION

The Exeter Universal femoral component has been used in total hip arthroplasty (THA) since 19881. In 2008, we reported the clinical and radiographic outcome of 104 consecutive primary cemented Exeter components in 78 patients under the age of 40 years at time of surgery.2 In that review, which had a mean follow-up of 6.2 years (2 to 13), the Kaplan-Meier survival analysis showed a probability of survival of the femoral component of 95.8% (95% CI 86.7 - 98.7) with revision for any reason as the endpoint, 100% for aseptic loosening, and 96.7% (95% CI 86.1 - 99.3) for radiological failure. Three femoral components had been revised due to infection. Although the results of our previous study were promising, the question remains as to 4 whether young patients with osteoarthritis of the hip should be treated with a cemented or an uncemented femoral component.3,4 Currently, there is a trend towards the use of uncemented implants. However, only by long-term follow-up studies can act as proof of concept for any hip implant to be established. The purpose of the present study is to update results of our previous report to a mean follow-up of 13.6 years (10-20), emphasizing on the clinical and radiographic results of the cemented Exeter stem to prove if this cemented stem has an acceptable outcome for younger people.

PATIENTS AND METHODS

The index primary arthroplasties were carried out between October 1993 and May 2004, during which time we performed 104 primary THAs in 78 consecutive patients using the Exeter Universal femoral component (Stryker Ltd, Newbury, United Kingdom). All patients were younger than 40 years at the time of surgery. The cohort included 34 men (44%) and 44 women (56%) with a mean age of 31 years (range 16 to 39 years). Of these, 26 patients underwent bilateral procedures, resulting in 50 left and 54 right THAs. Six patients (eight femoral components) had died of whom three patients (four stems) have been described in the previous report.2 These hips were followed until the patient died at 4.4, 5.3, 6.9, 7.5, 8.5, 8.6, 15.8, and 15.8 years respectively from causes not related to the surgery. Data of all deceased patients are included. The indications for the THR placement are summarised in Table І.

71 Cemented total hip arthroplasty and impaction bone grafting in young patients

TABLE І. Diagnosis at primary THA surgery (n=104) Indication Number (%)

Congenital hip dysplasia 30 (28.8%)

Corticosteroid induced avascular necrosis 23 (22.1%)

Rheumatoid Arthritis 13 (12.5%)

Idiopathic avascular necrosis 5 (4.8%)

Perthes’ disease 5 (4.8%)

Post-traumatic arthritis 5 (4.8%)

Slipped capital femoral epiphysis 4 (3.9%)

Morquio’s disease 4 (3.9%) 4 Various diagnoses 15 (14.4%)

The posterolateral approach was used in all cases except one. In this case, the patient underwent trochanteric osteotomy, as the surgeon decided to carry out a THA instead of the planned Sugioka osteotomy.5 All femoral components were inserted using the third generation cementing technique with antibiotic loaded Simplex® Bone Cement (Stryker Ltd, Newbury, United Kingdom). Various acetabular components were used in this cohort: Charnley Elite cup (Depuy, Leeds, U.K.), the Exeter low profile cup (Stryker Newbury, UK) and the Exeter Contemporary cup (Stryker, Newbury, UK). The cups used in this cohort were produced of traditionally polyethylene. The newer used Contemporary cups, which were used in large numbers were made of Duration crosslinked polyethylene. All of them were cemented (fig 1). The peri-operative care and follow-up of the patients has been previously described.2 Their clinical and radiographic follow-up was biennial. At follow- up, all patients were evaluated clinically using the Harris Hip Score (HHS)6, the Oxford Hip Score (OHS)7, and Visual Analogue Scales (VAS), graded 1-100, for pain in rest, pain during activity and overall satisfaction. In case of incomplete data collection at each review point, patients were contacted by telephone or mail for the missing data.

72 CHAPTER 4

Results of the cemented Exeter femoral component in patients under 40 years of age. An update at 10 to 20 years follow-up.

4

FIGURE 1. Radiographs showing the left Exeter femoral component in a 32-year-old man with corticosteroid induced avascular necrosis. A) pre-operative anteroposterior view of the left pelvis. B) left hip immediately post-operatively and c) 13 years post-operatively, with a stable prosthesis.

Radiographic analysis was performed while using the anteroposterior and the faux profile view of all femoral components. Radiolucent lines were graded according to the 14 zones as described by Gruen et al.8 and femoral loosening was scored using the criteria as described by Harris et al.9 The cementation grade was classified according to Barrack et al.10 Subsidence (mm) was measured for all femoral implants according to Loudon and Olders’ method.11 Heterotopic ossification was classified according to Brooker et al.12 All femurs were assessed for cortical hypertrophy and/or atrophy, rounding-off of the calcar, and cement fractures. Acetabular inclination (°) was measured on the immediate post- operative radiographs and the radiographs at last follow-up or the last radiograph prior to revision.13 Wear of the acetabular component was measured using Dorr and Wan’s method.14 Kaplan-Meier survival analysis including 95% confidence intervals (CI) was performed for four different endpoints; revision of the femoral component for any reason, aseptic loosening of the femoral component, septic loosening and radiographic failure. Furthermore, an overall Kaplan-Meier survival analysis was calculated with revision of any hip component (acetabular or femoral) for any reason as the endpoint. All statistical analyses were performed using SPSS IBM Statistics 22 (IBM, Armonk, New York,) and SAS 9.2 (SAS institute, Inc, Cary, North Carolina).

73 Cemented total hip arthroplasty and impaction bone grafting in young patients

RESULTS

At final review, four femoral components had been revised during the total study period, leaving 100 femoral components in 76 patients available for evaluation. Three had been revised because of infection after 2.2, 3.4, and 6.1 years, as we described in our previous report. One further femoral component had been revised for fracture of the prosthesis after 16.5 years. This component was removed and a cement in cement revision was carried out using again an Exeter stem. At final review, no femoral component had been revised for aseptic loosening.

4 Functional outcome Clinical scores were available in 99 out of all cases. The preoperative median HHS was 50 points (interquartile ranges 39-63), which improved to a median postoperative score of 93 points (interquartile ranges 77 to 98) at latest review. The median postoperative OHS was 18 points (interquartile ranges 12 to 24). The median VAS in rest was 0 points (interquartile ranges 0 to 20), during activity 0 points (interquartile ranges 0 to 30) and for satisfaction 90 points, (interquartile ranges 80 to 100) (table II).

TABLE ІІ. Clinical scores presented as mean (range) Preoperative score Postoperative score Postoperative score (range) at previous report at current update (range) (range) HHS 51 (15 – 77) 89 (55 – 100) 85 (36 – 100)

OHS 39 (28 – 52) 19 (12 – 45) 19 (12 – 38)

VAS rest 7 (0 – 75) 10 (0 – 70)

VAS physical activity 19 (0 – 90) 19 (0 – 90)

VAS satisfaction 87 (20 – 100) 85 (0 – 100)

Scores include the mean Harris Hip Score (HHS), mean Oxford Hip Score (OHS) and mean Visual Analogue Scale (VAS) scores for pain in rest, during physical activity and satisfaction. The mean was used to compare the scores of the current update to the mean scores published in the previous report.

74 CHAPTER 4

Results of the cemented Exeter femoral component in patients under 40 years of age. An update at 10 to 20 years follow-up.

Radiological outcome Radiographs were complete except in the case of one patient. The femoral component was implanted in more than 3° varus in 12 hips and and in more than 3° valgus in 11 hips. In the 100 unrevised hips, radiolucent lines were seen in 40 different Gruen zones in 16 stems. In 11 hips, the radiolucent lines were progressive and in five they were not. As described in our previous report one hip was considered radiographically loose with lucent lines in all Gruen zones except for zones 3, 4 and 5. However, the prosthesis was still in place at final follow-up, the radiolucent lines had not progressed and the patient remained asymptomatic. Osteolytic areas were seen in five hips in a total of seven zones. Subsidence of more than 2 mm was seen in 34 hips (table III) of which one was considered a radiological failure. In this case a Vancouver type B2 periprosthetic 4 fracture had occurred 11 years postoperatively, this was treated by plate fixation but without revision of the stem, resulting in subsidence of more than 5mm. Some cortical hypertrophy was seen in eight hips over a total of 15 zones, predominantly in zones 3,4 and 5 (87%). Cortical atrophy was only encountered in one hip in zone 7. Rounding-off of the calcar was observed in 16 hips. Overall, 11 out of 104 cups showed more than 2 mm of polyethylene wear at final follow-up or at time of revision.

TABLE III. Subsidence at latest follow-up by categories (n=103, 1 periprosthetic fracture excluded) Subsidence Number of cases

≤ 2 mm 70 (including 4 revisions)

>2 - ≤3 mm 23

>3 - ≤4 mm 8

>4 - ≤5 mm 2

Complications and reoperations unrelated to the femoral component In total, 14 acetabular components were revised, three as a part of a revision total hip arthroplasty due to septic loosening, one because of recurrent dislocations and one for loosening following injury. The other nine components were revised for aseptic loosening.

75 Cemented total hip arthroplasty and impaction bone grafting in young patients Treatment of dislocation Treatment Non-operative plus brace Non-operative Non-operative Non-operative Non operative plus brace Non operative Non-operative Non-operative plus brace Non-operative Non-operative plus brace Non-operative Non-operative Non-operative. Subsequent Subsequent Non-operative. of open reduction and exchange head femoral 2x non-operative subsequent subsequent 2x non-operative THA revision Non-operative Inclination Inclination final at follow-up(°) 49.3 26.7 49.2 49.6 56.8 NA 41.7 47.7 41.8 59.6 51.7 43.4 4 Inclination Inclination immediately post-op (°) 49.3 25.7 51.5 49.4 55.6 46.1 42.1 47.8 41.5 57.2 50.4 42.1 Type of acetabular of acetabular Type component Charnley Multicup 47/28 Charnley Multicup 50/28 Exeter 56/28 RSA Exeter Exeter 52/28 RSA Exeter Exeter 52/28 RSA Exeter Contemporary H 50/28 Contemporary Contemporary H 56/28 Contemporary Contemporary H 52/28 Contemporary Contamporary H 54/28 Contemporary H 50/28 Contemporary Contemporary H 60/28 Contemporary Contemporary H 58/28 Contemporary Stem position neutral 3,6° valgus neutral neutral 5,0° valgus neutral neutral neutral neutral 11,8° varus neutral 3,2° varus Indication/ HistoryIndication/ Avascular necrosis previous previous necrosis Avascular sugioka osteotomy Avascular necrosis associated associated necrosis Avascular usage steroid necrosis avascular idiopathic Avascular necrosis associated associated necrosis Avascular usage steroid Avascular Necrosis associated associated Necrosis Avascular usage steroid Severe rheumatoid arthritis rheumatoid Severe Avascular necrosis, previous previous necrosis, Avascular femoral DDH and proximal de-rotational osteotomy DDH and previous pelvic DDH and previous osteotomy Severe rheumatoid arthritis rheumatoid Severe fracture femoral and proximal Previous perthes disease and Previous chiari pelvic osteotomy Avascular Necrosis previous previous Necrosis Avascular Sugioka osteotomy Avascular necrosis previous previous necrosis Avascular sugioka osteotomy Gender M M M M F F F F F M M M TABLE IV. TABLE Case nr Case 57/41 Detailed information on the dislocated total hip arthroplasties total Detailed information on the dislocated 59/45 62/51 63/52 67/56 68/57 71/60 76/65 81/70 85/74 98/88 100/90 DDH = Developmental Dysplasia, THA=total hip arthroplaty, M= Male, F=Female, NA= not avalaible F=Female, DDH = Developmental Dysplasia, M= Male, hip arthroplaty, THA=total

76 CHAPTER 4

Results of the cemented Exeter femoral component in patients under 40 years of age. An update at 10 to 20 years follow-up.

Previously we reported three patients with a deep infection and three hips with a superficial infection. Dislocation occurred in 12 hips, nine of which were treated conservatively and three underwent re-operation. The mean acetabular inclination immediately post- operative was 46,0° (range 34.1-66.2) in the non-dislocated hips (n=89 ) and 46,6° (range 25.7-57.2) in the hips that dislocated afterwards (n=12). Three were not measurable due to the mesh reconstruction. No additional dislocations in time after our previous report were observed. Detailed information regarding diagnosis and cup positioning in these dislocating hips is displayed in table IV. Heterotopic ossifications was seen in a total of 31 patients; 12 were grade I, 13 grade II, and 6 grade III.

Survival analysis 4 Kaplan-Meier survival analysis for the femoral component at up to 17 years follow-up showed survival rates of 92.1% (95% CI: 74.1-97.8) for revision for any reason (fig 2), 100% for aseptic loosening (95% CI: 83.8-100) (fig 3), and 91.3% (95% CI: 71.5-97.6) for radiographic loosening (table V). The overall Kaplan-Meier survival was 87.4% (95% CI: 79.3-92.5) at ten years and 75.7% (95% CI: 58.2-86.6) at 17 years with revision of any hip component for any reason as the endpoint.

TABLE V. Kaplan-Meier survival analysis for all Exeter femoral components Revision for Revision for Revision for Failure for any reason aseptic loosening septic loosening radiographic loosening (95% CI) (95% CI) (95% CI) (95% CI) 10-year survival 97.1% (91.3 - 99.1) 100% (96.7 - 100) 97.1 (91.3 - 99.1) 98.0 (92.3 - 99.5)

17-year survival 92.1% (74.1 - 97.8) 100% (83.8 - 100) 97.1 (91.3 - 99.1) 91.3 (71.5 - 97.6)

77 Cemented total hip arthroplasty and impaction bone grafting in young patients

1.0

0.

0.

0.4

Proportion revision free 0.2

0.0 4 0 10 1 20

Follow-up (years)

FIGURE 2. Stem survival for the endpoint revision for any reason.

1.0

0.

0.

0.4

Proportion revision free 0.2

0.0 0 10 1 20

Follow-up (years)

FIGURE 3. Stem survival for the endpoint aseptic loosening.

78 CHAPTER 4

Results of the cemented Exeter femoral component in patients under 40 years of age. An update at 10 to 20 years follow-up.

DISCUSSION

In this study we report the outcome of a series of all-cemented THA using the Exeter Universal cemented femoral component in patients under the age of 40 at time of their primary arthroplasty. Survival of the femoral component remained at 100% for aseptic loosening, with only one additional revision for fracture of the femoral component. This specific patient who weighed > 75 kg, had a very narrow femoral canal and a short, 35.5 mm offset Exeter stem was implanted. However, these small components are rather slim proximally and we recommend they are not used in patients with a weight over 60 kilograms (Exeter, Newburry, UK). At revision the distal part of the fractures prosthesis was easily removed and we re-implanted a new Exeter femoral component. One further 4 complication, a periprosthetic fracture from a fall, was treated by plate fixation. The mean clinical scores remained satisfying over this period of follow-up and interestingly they are almost identical to our previous report, showing no significant decline between a mean follow-up of six and 13 years. The outlier functional and patient-reported outcome scores can be explained by co-morbidities, for example severe rheumatic arthritis, which limits overall function. One patient had an outlier VAS score for satisfaction of 0, caused by neurogenic defunctioning of his hip abductor muscles. There are some limitations to our study. The clinical scores of 20 patients were completed after their visit to the outpatients clinic, either by telephone or by mail. One patient was lost to radiological follow-up after six years, but clinically continued to report no concerns with their hip, suggesting that aseptic loosening is unlikely. Unfortunately, although we used standard hip scores, we did not actively collect data about sports activities, which may be of interest when treating younger patients. Some further radiological changes were noted at final follow-up, including an increase in radiolucent lines. This highlights the need for ongoing follow-up of younger patients. As illustrated in Table VI, most femoral components had radiolucent lines in only one or two Gruen zones. The 16% of hips with radiolucent lines in the 100 unrevised cases is higher than the 9.8% reported by Lewthwaite et al,15 in their study using the Exeter Universal femoral component and the 8.5% reported by Carrington et al16 at 15.7 years. This last study included patients of all ages. None of our patients had a Barack cementing C cement mantle and 11 of the 16 patients with radiolucent lines, subsidence of the component was 2 mm or less. There was no relationship between femoral component

79 Cemented total hip arthroplasty and impaction bone grafting in young patients

subsidence and radiolucent lines in our study. On hip showed radiological signs of loosening of the femoral component, which were probably related to technical problems during the surgery because the centralizer was accidently not inserted. This patient did not show any radiological signs of acetabular component wear. Overall, we did not find any correlation between acetabular wear and the presence of femoral radiolucent lines. Only four of the 16 hips that had radiolucent lines around the femoral component had evidence of polyethylene wear of more than 2 mm.

TABLE VI. Displaying the number of patients with radiolucent lines including 4 the Gruen Zones involved. Gruen Zones with Radiolucent lines Number of cases (n) 0 84 1 2 2 1 7 3 8 1 12 1 13 1 1+8 2 8+14 1 9+10+11 1 1+6+7+8+9 1 1+7+10+11+12+13 1 1+2+6+7+8+9+10+11+12+13+14 1

Loudon and Older11 described femoral subsidence of more than 2 mm as abnormal. Williams et al1 reported that subsidence occurred in all Exeter components and Carrington et al16 showed a slow progressive increase in subsidence over time without clinical consequences. They stated that the definition of loosening as described by Harris et al9 is not appropriate to describe polished femoral components as their fixation is based

80 CHAPTER 4

Results of the cemented Exeter femoral component in patients under 40 years of age. An update at 10 to 20 years follow-up. on the taper slip principle.17 Component subsidence slows with time in RSA studies and subsidence occurs within the cement mantle. This results in continuous compression of the cement and a bone-cement interface that maintains the secure fixation. This mode of action is completely different from other cemented designs such as the Charnley or Charnley Elite, which are not tapered and function as a “force closed” femoral component. They are not designed to subside: any subsidence takes place at the bone-cement interface which affects the stability of the implant.18 An alternative method of measuring subsidence was described by Fowler et al19. Some authors now define subsidence of >5 mm to be abnormal or even do not use subsidence as a criterion for defining radiological failure.15,20 In this study we found no difference in subsidence using either method. Only one 4 femoral component migrated more than 5 mm and this was due to periprosthetic fracture. We did not find a strong relationship between the Barrack cement grading and subsidence, except for a relative higher number Barrack B cement mantles in stems with 3mm to 4 mm subsidence. We noted an increase in femoral cortical hypertrophy in eight hips, in the distal Gruen zones. This appearance may indicate that the femoral component is loading the femoral shaft distally. The mean subsidence in these eight hips was 1.78, compared with 1.70 mm for the whole group, and did not reach significance. A number of dislocations were seen during the analysis, as we described in our original report. No further dislocations had occurred at final review. The reasons for dislocation remain unclear. Often patients with dislocations have had previous surgery, including osteotomies, or have abnormal anatomy of the hip, e.g. dysplasia. Alignment of the femoral component does not appear to affect this. The inclination of the acetabular component in patients with instability are shown in Table IV. The mean values show no difference to the cohort as whole. The design of the acetabular component used in the early part of the study may have had some bearing on outcome. A relatively high number of dislocations were seen with designs which had an elevated posterior rim (Contemporary hooded component, traditional Exeter components). This has been previously reported.21 Cemented femoral components in young patients have given results varying from poor to excellent.1,15,16,22-33 Uncemented femoral components have become increasingly popular.4,34-38 The literature comparing uncemented with cemented implants includes

81 Cemented total hip arthroplasty and impaction bone grafting in young patients

reports in which obsolete cementing techniques or the use of a particular implant have been associated with a poorer outcome.3,34,35,37 The longer-tem survival of cemented implants has been improved substantially since third generation cementing techniques were introduced,15 and results are comparable with those of uncemented components. Kim et al 39 reports a survival of cemented femoral components of 96% (95% CI 91- 100) at 26.1 years and 95% (95% CI 90-100) for uncemented stems at 26.1 years. Another of their series showed almost no difference between the Charnley Elite or Elite Plus stem and the cementless Profile stem at 20 years follow up with survival for any reason of 97% (95% CI 91-100) and 96% (95% CI 93-100) respectively.4 Factors contributing to these improved results for both cemented and noncemented stems in this study are the better 4 cementation technique, better surgical skills regarding the uncemented implants and the improved designs of the femoral component. That is confirmed by Callaghan et 40al who noted a 5% femoral revision rate at 23.3 years patients whose average age was 42 years. When performing the cemented technique, polished tapered stems are nowadays widely used and have been reported frequently in literature.20,24,41 Regarding in detail series of patients under 40 years, both cemented and uncemented femoral components seem to be an acceptable solution. In our former report we already mentioned Joshi et al, reporting a 97% survival at ten years with revision due to aseptic loosening as the endpoint for the original Charnley component and Chmell et al28 reporting a survival rate of 95% at ten years with a variety of femoral components in patients under the age of 35. Garcia-Cimbrelo et al27 reports the survival of the Charnley flatback stainless steel stem inserted with a finger packing technique resulting in 5-, 15-, and 24-, year survival rates of 97%, 82%, 74%. Lampropoulou et al42 describes an overall probability of survival of 41 consecutive Charnley low-friction arthroplasty, with failure for aseptic loosening as the endpoint, of 95.1% (95% CI 91.75-98.45) at 10 years, 77.1 (95% CI 73.9-803) at 20 years. Simon et al23 shows no revisions of the in total 34 polished triple tapered cemented MS-30TM and the polished double tapered cemented ExeterTM after a mean FU of 10.9 years in patients with avascular necrosis of the femoral head. In 57 hips in patients with inflammatory arthritis no revision of the femoral component (inserted with hand mixed cement) was needed after a mean FU of 12.2 years (range 7-19).25 For 49 uncemented stems Wangen et al43 reported at a minimum follow up of ten years that all fully coated with HA straight stems were well integrated, and no revisions were performed. Kim et al44 shows no aseptic loosening for their IPS femoral component

82 CHAPTER 4

Results of the cemented Exeter femoral component in patients under 40 years of age. An update at 10 to 20 years follow-up.

(DePuy, Leeds, united Kingdom) after a minimum of ten years and Girard et al45, reports a 100% survival in a cohort combining both cemented and uncemented stems at a mean of 108 months.

In conclusion, we present an update of a cohort of young patients with hip osteoarthritis who all were treated with the Exeter cemented stem under the age of 40 years. In time we saw in 10% of the stems an increase in radiolucent lines, but no increase in radiographic loosening. In the future monitoring of these radiolucent lines will be necessary. The survival of this femoral component for aseptic loosening remained satisfying with a 100% survival at 17 years of follow-up, and the overall survival only slightly declined because of one stem fracture. The clinical outcome remained good. Therefore we think the use of 4 cemented femoral components is an acceptable treatment option in very young patients.

83 Cemented total hip arthroplasty and impaction bone grafting in young patients

REFERENCES

1. Williams HD, Browne G, Gie GA, Ling RS, Timperley AJ, Wendover NA. The Exeter universal cemented femoral component at 8 to 12 years. A study of the first 325 hips. J Bone Joint Surg Br 2002;84-3:324-34. 2. de Kam DC, Klarenbeek RL, Gardeniers JW, Veth RP, Schreurs BW. The medium-term results of the cemented Exeter femoral component in patients under 40 years of age. J Bone Joint Surg Br 2008;90-11:1417-21. 3. Gee MJ, Ajuied A, Shah Z, George M, Bankes MJ. Systematic review of total hip arthroplasty in patients under 30 years old. Hip Int 2013;23-4:345-51. 4 4. Kim YH, Kim JS, Park JW, Joo JH. Comparison of total hip replacement with and without cement in patients younger than 50 years of age: the results at 18 years. J Bone Joint Surg Br 2011;93-4:449-55. 5. Sugioka Y. Transtrochanteric anterior rotational osteotomy of the femoral head in the treatment of osteonecrosis affecting the hip: a new osteotomy operation. Clin Orthop Relat Res 1978-130:191-201. 6. Harris WH. Traumatic arthritis of the hip after dislocation and acetabular fractures: treatment by mold arthroplasty. An end-result study using a new method of result evaluation. J Bone Joint Surg Am 1969;51-4:737-55. 7. Dawson J, Fitzpatrick R, Carr A, Murray D. Questionnaire on the perceptions of patients about total hip replacement. J Bone Joint Surg Br 1996;78-2:185-90. 8. Gruen TA, McNeice GM, Amstutz HC. “Modes of failure” of cemented stem-type femoral components: a radiographic analysis of loosening. Clin Orthop Relat Res 1979-141:17-27. 9. Harris WH, McCarthy JC, Jr., O’Neill DA. Femoral component loosening using contemporary techniques of femoral cement fixation. J Bone Joint Surg Am 1982;64-7:1063-7. 10. Barrack RL, Mulroy RD, Jr., Harris WH. Improved cementing techniques and femoral component loosening in young patients with hip arthroplasty. A 12-year radiographic review. J Bone Joint Surg Br 1992;74-3:385-9. 11. Loudon JR, Older MW. Subsidence of the femoral component related to long-term outcome of hip replacement. J Bone Joint Surg Br 1989;71-4:624-8. 12. Brooker AF, Bowerman JW, Robinson RA, Riley LH, Jr. Ectopic ossification following total hip replacement. Incidence and a method of classification. J Bone Joint Surg Am 1973;55- 8:1629-32.

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Results of the cemented Exeter femoral component in patients under 40 years of age. An update at 10 to 20 years follow-up.

13. Nomura T, Naito M, Nakamura Y, Ida T, Kuroda D, Kobayashi T, Sakamoto T, Seo H. An analysis of the best method for evaluating anteversion of the acetabular component after total hip replacement on plain radiographs. Bone Joint J 2014;96-B-5:597-603. 14. Dorr LD, Wan Z. Comparative results of a distal modular sleeve, circumferential coating, and stiffness relief using the Anatomic Porous Replacement II. J Arthroplasty 1996;11-4:419-28. 15. Lewthwaite SC, Squires B, Gie GA, Timperley AJ, Ling RS. The Exeter Universal hip in patients 50 years or younger at 10-17 years’ followup. Clin Orthop Relat Res 2008;466-2:324-31. 16. Carrington NC, Sierra RJ, Gie GA, Hubble MJ, Timperley AJ, Howell JR. The Exeter Universal cemented femoral component at 15 to 17 years: an update on the first 325 hips. J Bone Joint Surg Br 2009;91-6:730-7. 17. Murray DW, Gulati A, Gill HS. Ten-year RSA-measured migration of the Exeter femoral 4 stem. Bone Joint J 2013;95-B-5:605-8. 18. Alfaro-Adrian J, Gill HS, Murray DW. Should total hip arthroplasty femoral components be designed to subside? A radiostereometric analysis study of the Charnley Elite and Exeter stems. J Arthroplasty 2001;16-5:598-606. 19. Fowler JL, Gie GA, Lee AJ, Ling RS. Experience with the Exeter total hip replacement since 1970. Orthop Clin North Am 1988;19-3:477-89. 20. Firestone DE, Callaghan JJ, Liu SS, Goetz DD, Sullivan PM, Vittetoe DA, Johnston RC. Total hip arthroplasty with a cemented, polished, collared femoral stem and a cementless acetabular component. A follow-up study at a minimum of ten years. J Bone Joint Surg Am 2007;89-1:126-32. 21. Schmitz MW, Timmer C, Rijnen WH, Gardeniers JW, Schreurs BW. Clinical and radiological outcome of the cemented Contemporary acetabular component in patients < 50 years of age. Bone Joint J 2013;95-B-12:1617-25. 22. Howie DW, Costi K, McGee MA, Standen A, Solomon LB. Femoral bone is preserved using cemented polished stems in young patients. Clin Orthop Relat Res 2012;470-11:3024-31. 23. Simon JP, Berger P, Bellemans J. Total hip arthroplasty in patients less than 40 years old with avascular necrosis of the femoral head. A 5 to 19-year follow-up study. Acta Orthop Belg 2011;77-1:53-60. 24. Burston BJ, Yates PJ, Hook S, Moulder E, Whitley E, Bannister GC. Cemented polished tapered stems in patients less than 50 years of age: a minimum 10-year follow-up. J Arthroplasty 2010;25-5:692-9.

85 Cemented total hip arthroplasty and impaction bone grafting in young patients

25. Simon JP, Maes M, Robbens E, Bellemans J. Total hip arthroplasty in inflammatory arthritis in patients under 35 years. A 7 to 19 year follow-up. Hip Int 2010;20-2:163-70. 26. Keener JD, Callaghan JJ, Goetz DD, Pederson DR, Sullivan PM, Johnston RC. Twenty-five- year results after Charnley total hip arthroplasty in patients less than fifty years old: a concise follow-up of a previous report. J Bone Joint Surg Am 2003;85-A-6:1066-72. 27. Garcia-Cimbrelo E, Cruz-Pardos A, Cordero J, Sanchez-Sotelo J. Low-friction arthroplasty in patients younger than 40 years old: 20- to 25-year results. J Arthroplasty 2000;15-7:825-32. 28. Chmell MJ, Scott RD, Thomas WH, Sledge CB. Total hip arthroplasty with cement for juvenile rheumatoid arthritis. Results at a minimum of ten years in patients less than thirty years old. J Bone Joint Surg Am 1997;79-1:44-52. 4 29. Devitt A, O’Sullivan T, Quinlan W. 16- to 25-year follow-up study of cemented arthroplasty of the hip in patients aged 50 years or younger. J Arthroplasty 1997;12-5:479-89. 30. Sochart DH, Porter ML. Long-term results of cemented Charnley low-friction arthroplasty in patients aged less than 30 years. J Arthroplasty 1998;13-2:123-31. 31. Dorr LD, Kane TJ, 3rd, Conaty JP. Long-term results of cemented total hip arthroplasty in patients 45 years old or younger. A 16-year follow-up study. J Arthroplasty 1994;9-5:453-6. 32. Sullivan PM, MacKenzie JR, Callaghan JJ, Johnston RC. Total hip arthroplasty with cement in patients who are less than fifty years old. A sixteen to twenty-two-year follow-up study. J Bone Joint Surg Am 1994;76-6:863-9. 33. Joshi AB, Porter ML, Trail IA, Hunt LP, Murphy JC, Hardinge K. Long-term results of Charnley low-friction arthroplasty in young patients. J Bone Joint Surg Br 1993;75-4:616-23. 34. Eskelinen A, Paavolainen P, Helenius I, Pulkkinen P, Remes V. Total hip arthroplasty for rheumatoid arthritis in younger patients: 2,557 replacements in the Finnish Arthroplasty Register followed for 0-24 years. Acta Orthop 2006;77-6:853-65. 35. Takenaga RK, Callaghan JJ, Bedard NA, Liu SS, Klaassen AL, Pedersen DR. Cementless total hip arthroplasty in patients fifty years of age or younger: a minimum ten-year follow-up. J Bone Joint Surg Am 2012;94-23:2153-9. 36. McAuley JP, Szuszczewicz ES, Young A, Engh CA, Sr. Total hip arthroplasty in patients 50 years and younger. Clin Orthop Relat Res 2004-418:119-25. 37. McLaughlin JR, Lee KR. Total hip arthroplasty with an uncemented tapered femoral component in patients younger than 50 years. J Arthroplasty 2011;26-1:9-15.

86 CHAPTER 4

Results of the cemented Exeter femoral component in patients under 40 years of age. An update at 10 to 20 years follow-up.

38. Biemond JE, Pakvis DF, van Hellemondt GG, Buma P. Long-term survivorship analysis of the cementless Spotorno femoral component in patients less than 50 years of age. J Arthroplasty 2011;26-3:386-90. 39. Kim YH, Park JW, Kim JS, Kim IW. Twenty-Five- to Twenty-Seven-Year Results of a Cemented vs a Cementless Stem in the Same Patients Younger Than 50 Years of Age. J Arthroplasty 2015. 40. Callaghan JJ, Forest EE, Sporer SM, Goetz DD, Johnston RC. Total hip arthroplasty in the young adult. Clin Orthop Relat Res 1997-344:257-62. 41. Yates PJ, Burston BJ, Whitley E, Bannister GC. Collarless polished tapered stem: clinical and radiological results at a minimum of ten years’ follow-up. J Bone Joint Surg Br 2008;90-1:16- 22. 42. Lampropoulou-Adamidou K, Georgiades G, Vlamis J, Hartofilakidis G. Charnley low-friction 4 arthroplasty in patients 35 years of age or younger. Results at a minimum of 23 years. Bone Joint J 2013;95-B-8:1052-6. 43. Wangen H, Lereim P, Holm I, Gunderson R, Reikeras O. Hip arthroplasty in patients younger than 30 years: excellent ten to 16-year follow-up results with a HA-coated stem. Int Orthop 2008;32-2:203-8. 44. Kim YH, Park JW, Kim JS. Cementless metaphyseal fitting anatomic total hip arthroplasty with a ceramic-on-ceramic bearing in patients thirty years of age or younger. J Bone Joint Surg Am 2012;94-17:1570-5. 45. Girard J, Bocquet D, Autissier G, Fouilleron N, Fron D, Migaud H. Metal-on-metal hip arthroplasty in patients thirty years of age or younger. J Bone Joint Surg Am 2010;92-14:2419- 26.

87

Acetabular reconstructions with impaction bone-grafting and a cemented cup in patients younger than fifty years old A concise follow-up, at twenty-seven to thirty-five years, of a previous report

Marloes W.J.L. Schmitz, Gerjon Hannink,

Jean W.M. Gardeniers, Nico Verdonschot,

Tom J.J.H. Slooff, B. Willem Schreurs

Accepted for publication in the Journal of Bone and Joint Surgery

CHAPTER 5 Cemented total hip arthroplasty and impaction bone grafting in young patients

ABSTRACT

We currently present the update of the 19 acetabular reconstructions that were still in situ at our previous report. All were performed with a cemented total hip arthroplasty and impaction bone grafting. At a mean follow-up period of 30 years (range, 27 to 35 years) no additional patients were lost to follow-up during the current follow-up. Two additional patients (3 reconstructions) died. None of these were related to the surgery. An additional 5 reconstructions in 5 patients were revised, 4 for aseptic loosening and 1 for septic loosening, after a mean of 24 years (range 22 to 27 years), leaving 11 surviving hips in 11 patients which were clinically and radiographically evaluated. Kaplan-Meier survival at 30 years for the acetabular reconstructions regarding 5 endpoints revision for any reason and aseptic loosening were 0.40 (95% CI: 0.23- 0.56) and 0.56 (95% CI: 0.35-0.73) respectively. Competing risk analysis showed that Kaplan-Meier overestimates the revision risk by 18% and 22%, respectively. Regarding radiographic loosening, survival was 0.53 (95% CI: 0.33-0.69) at 30 years. In conclusion, cemented impaction bone grafting can be used as a reasonable long-term solution for demanding primary and revision acetabular reconstructions in young patients with acetabular bone defects.

90 CHAPTER 5

Acetabular reconstructions with impaction bone-grafting and a cemented cup in patients younger than fifty years old A concise follow-up, at twenty-seven to thirty-five years, of a previous report

BACKGROUND

There are no literature data available of the survival of acetabular reconstructions in young patients at 30 years or more after surgery. Only a few long term reports are available, which all describe a significant shorter duration of follow-up1-3. Therefore, we update the long-term outcome of our original cohort of 42 consecutive acetabular reconstructions with impaction bone grafting using morselized cancellous bone graft and a cemented cup 4, 5. The patient demographics have been displayed in Table I. We used impaction bone-grafting as a biological technique to reconstruct acetabular deficiencies in these younger patients. This consecutive cohort consisted of 23 primary and 19 revision acetabular reconstructions in 37 patients. Mean age was 37 years (range, 20 to 49 years) at the time of surgery.

TABLE I. 5 Patient Demographics Patients (n) (%) Reconstructions (n) (%)

In series 37 100 42 100

Sex

F 22 60 24 57

M 15 40 18 43

Type of defects according to AAOS classification

Segmental 1 2

Cavitary 27 64

Combined 14 33

Deaths during follow-up period 7 19 9 21

Lost to follow-up 1 3 1 2

Revisions during follow-up 21 50

Due to septic loosening 3 7

Due to aseptic loosening 12 2

Due to wear 4 10

During stem revision 2 5

Six surgeons were involved in this single center study. Clinical and radiographical data were collected prospectively. In our first paper the minimum follow-up was 15 years; 1 patient was lost to follow up (1 reconstruction) and 4 patients (5 reconstructions) had

91 Cemented total hip arthroplasty and impaction bone grafting in young patients

died. Four primary and 4 revision reconstructions were (re-)revised. The acetabular revision for any reason Kaplan-Meier analysis revealed a 20-year survival rate of 0.80 (95% confidence interval, 0.67-0.94) as can be seen in Table II. The average follow-up of the next update report was 23 years (range, 20 to 28 years)4. One more patient had died and another 8 cups had to be revised resulting in a total of 16 (re)revisions (7 primary and 9 revisions), leaving 19 surviving reconstructions in 17 patients. The Kaplan-Meier analyses showed a survival of the acetabular component at 25 years of 0.52 (95% confidence interval, 0.35 to 0.72) with endpoint removal of the cup for any reason (Table II). The purpose of the present study was to update the clinical and radiographic results of the 19 surviving reconstructions of our previous report after a mean follow-up of 30 years (range, 27 to 35 years) in these young patients. 5 MATERIALS AND METHODS

In this update, 19 surviving reconstructions in 17 patients are presented. This includes 10 primary reconstructions and 9 revision reconstructions in 5 male and 12 female patients. All had received the combination of a cemented cup and IBG which was the only technique used in our department to treat acetabular bone stock loss. A posterior approach was used and after resection of the femoral head or removal of the failed component the IBG technique was performed as previously described4, 5. In short, segmental defects were reconstructed with use of a metal mesh or a solid graft. The femoral head was used as autograft or autogenous bone from the iliac crest was used. In case of revision surgeries fresh frozen non-irradiated femoral head allografts were used, while in case of revision surgeries performed after hip resurfacing arthroplasty, reconstructions with use of the femoral head, the iliac crest or autogenous bone from the iliac crest combined with a femoral allograft were performed. After lavage, the grafts were impacted and the defect was reconstructed layer-by-layer using a trial acetabular prosthesis and a mallet. In 16 of these 19 reconstructions a thin Vitallium wire mesh (Mecron, Berlin, Germany) was used to cover the graft. After pressurization of the bone cement, a 32 mm all-polyethylene cup was inserted. Eleven of the original 25 Muller and 8 of the original 17 Allopro cups (Sulzer, Winterthur, Switzerland) were reviewed. Further details have been described in our previous reports4, 5.

92 CHAPTER 5

Acetabular reconstructions with impaction bone-grafting and a cemented cup in patients younger than fifty years old A concise follow-up, at twenty-seven to thirty-five years, of a previous report 0.53 (0.33-0.69) 0.56 (0.35-0.73) 0.40 (0.23-0.56) 30-Year KM 30-Year (95% Confidence Interval) 0.61 (0.42-0.75) 0.70 (0.50-0.83) 0.62 (0.44-0.80) 0.50 (0.32-0.65) 0.77 (0.62 -0.92) 25-Year KM 25-Year (95% Confidence Interval) 0.52 (0.35-0.72)

5 - 0.71 (0.55-0.86) 0.91 (0.80-1) 0.85 (0.72-0.97) 20-Year KM 20-Year (95% Confidence Interval) 0.80 (0.67-0.94) 0.73 (0.58-0.87) 0.89 (0.80-0.99) 0.89 (0.80-0.99) 0.94 (0.87-1) 0.94 (0.87-1.00) 15-Year KM 15-Year (95% Confidence Interval) 0.83 (0.72-0.96) 0.84 (0.72-0.96) 0.92 (0.84-1) 0.97 (0.92-1) 10-Year KM 10-Year (95% Confidence Interval) 0.92 (0.84-1) 4 5 publication publication Radiographic loosening Aseptic loosening Aseptic Revision for any reason any Revision for Radiographic loosening Radiographic loosening Aseptic loosening Aseptic loosening Aseptic Revision for any reason any Revision for reason any Revision for st nd TABLE II. II. TABLE 2 Current update Current End Point for Survival for (KM) of End Point Reconstructions Acetabular 1 Survival rates for the 3 endpoints after different periods of follow-up of the acetabular reconstructions of the first and second publication and publication of the first and second reconstructions of the acetabular for the 3 endpoints afterperiods of follow-up different Survival rates update the current

93 Cemented total hip arthroplasty and impaction bone grafting in young patients

All reconstructions were prospectively followed clinically and radiographically, annually or biennially for a minimum of 27 years or until revision or death. As in our prior publications, acetabular defects were classified by the AAOS classification system6 (Table I). Anteroposterior and lateral radiographs were reviewed for radiographic evidence of graft incorporation7, osteolysis and radiolucent line formation8, heterotopic ossification9 and linear polyethylene wear10. At final review all patients with surviving hips were seen for clinical and radiographic review and their Harris hip score (HHS) and the Oxford Hip Questionnaire Score11 were again obtained. All patients who died during the follow-up period were followed until their death. Their data including revisions and radiographical examinations were included in this report. Survival analyses were performed for 3 endpoints: revision of the acetabular component for any reason, revision for aseptic loosening, and radiographical failure. 5 The latter was defined as radiolucent lines in all 3 zones of Charnley and DeLee or a migration of 5 mm or more in any direction relative to the interteardrop line as seen on the anteroposterior radiograph. In the presence of a competing risk such as death, the standard Kaplan-Meier method will always overestimate the true revision rate12-15. Due to the long term follow-up and the increasing number of patients who died throughout the study period we calculated not only Kaplan-Meier survival estimates but also took into account the competing risk of death. Standard Kaplan-Meier survival analysis was used to estimate the survival percentage (KM) for each of the 3 endpoints. The estimated percentage of procedures revised was calculated as 1 – estimated survival percentage (1-KM). To take into account the competing risk of death, the cumulative incidence function (CIF) of revisions in the presence of death was used. Analyses were performed for the whole group of reconstructions and stratified by primary and revision acetabular reconstructions. Log-rank tests were used to test differences between Kaplan-Meier estimates of primary and revision acetabular reconstructions, Gray’s (log-rank) tests were used to test differences in CIF between groups. Kaplan-Meier and cumulative incidence function estimates were reported with their 95% confidence intervals (CIs). Statistical analyses were performed using R (version 3.2.4) with packages ‘rms’ and ‘cmprsk’16-18.

94 CHAPTER 5

Acetabular reconstructions with impaction bone-grafting and a cemented cup in patients younger than fifty years old A concise follow-up, at twenty-seven to thirty-five years, of a previous report

RESULTS

Clinical results Of the 19 reconstructions in 17 patients which were available for this update report, no additional patients were lost to follow-up during the current follow-up. Two additional patients (3 reconstructions) died. None of these were related to the surgery. An additional 5 reconstructions in 5 patients were revised after a mean of 24 years (range 22 to 27 years), leaving 11 surviving hips in 11 patients which were clinically and radiographically evaluated after a mean follow-up period of 30 years (range, 27 to 35 years). All of them were able to attend our outpatient clinic for review. The mean Harris hip score of these surviving hips was 88 (range, 59 to 100) and the mean Oxford Hip Questionnaire Score was 20 (range, 12 to 40). Regarding the entire group of 42 reconstructions in 37 patients, 1 patient (1 reconstruction) has been lost to follow-up already since the first report. 7 patients (9 5 reconstructions) died.

Revisions Four out of 5 additional revisions presented in this updated review of the acetabular reconstructions were revised for aseptic loosening, which in one case occurred a few weeks after a traumatic event. One additional reconstruction was revised showing culture-proven coagulase negative staphylococcus septic loosening at 22.5 years. In this update, no additional revisions for wear or osteolysis were performed.

Revisons entire original cohort Overall, 21 out of 41 acetabular reconstructions of the original whole cohort have been revised for any reason after minimal 27 years of follow-up. Of these 21 revisions, 12 were performed because of aseptic loosening after mean 19.8 years (range, 6.4 to 27.0 years): 7 originally had a cavitary defect (type-2) and 5 a combined defect (type-3). Six were primary reconstructions, and 6 were revision reconstructions. Four reconstructions were revised because of wear and osteolysis after a mean of 18.8 years (range, 8.9-23.2 years), showing no intra-operative or radiographical loosening. Three reconstructions were revised because of culture-proven septic loosening after 3, 14.5 and 22.5 years. Another 2 reconstructions had been revised at 12.3 and 18.3 years during a revision of the stem

95 Cemented total hip arthroplasty and impaction bone grafting in young patients

because of persistent instability and matching problems. These 2 reconstructions were both intra-operatively and radiographically well fixed.

Radiographic results of the non-revised reconstructions Six of the 11 surviving acetabular reconstructions showed radiolucent lines in 1 or 2 zones of Charnley and DeLee. All of them were stable and had not shown any progression since the last update in 2011. No osteolysis was seen around these eleven reconstructions. None of the 11 surviving cups showed radiographic loosening. Six reconstructions showed periarticular ossifications Brooker grade I, one grade II and one grade III. The mean polyethylene wear for all surviving implants was 2.3 mm (range, 1.2 to 4.2 mm). We also studied the 9 non-revised reconstructions in the 7 deceased patients. One patient (1 reconstruction) has not been able to attend the outpatient clinic in one of our previous reports due to dementia over the last years before she died. We used 5 her last available radiograph available from 2005. For another 2 deceased patients (3 reconstructions) radiographic data were incomplete. With these limitations, none of the reconstructions was radiographically loose, 2 showed a progressive line in one acetabular zone and two showed a non-progressive radiolucent line in one acetabular zone. None showed osteolysis.

Radiographic Results of the revised reconstructions Of the entire original cohort of 21 revised reconstructions, 15 showed definitive radiographic loosening of the cup (Table III). Nine had radiolucent lines in all three zones, 3 cups migrated more than 5 mm. Of the other 6 revised reconstructions, 3 showed radiolucent lines in one zone and 1 showed radiolucent lines in two zones. Two of them showed osteolysis in one zone. The mean polyethylene wear of the revised reconstructions up to last follow-up was 2.3 mm (range, 0 to 4.2 mm).

96 CHAPTER 5

Acetabular reconstructions with impaction bone-grafting and a cemented cup in patients younger than fifty years old A concise follow-up, at twenty-seven to thirty-five years, of a previous report + - Y Radiographic loosening Y Y Y Y Y Y Y Y Y Y Y N N Y Y Y N N N N Osteolysis ------1 - - - 3 ------1 3 Migration - > 5 mm > 5 mm - Tilting > 5 mm Tilting - - - > 5 mm > 5 mm - - - > 5 mm - - - - - M=Muller, A=Allopro (Sulzer, Winterthur, Switzer Winterthur, (Sulzer, A=Allopro M=Muller, ± 5 Radiolucent lines Radiolucent 1+2+3 - - 1+2+3 1+2+3 - 3 1+2+3 1+2+3 1+2+3 - 1+2+3 1+3 - 1+2+3 - 1+2+3 1 3 - 3 Reason for revision Reason for Aseptic loosening Aseptic Aseptic loosening Aseptic Aseptic loosening Aseptic Aseptic loosening Aseptic Aseptic loosening Aseptic Aseptic loosening Aseptic Aseptic loosening Aseptic Aseptic loosening Aseptic Aseptic loosening Aseptic Aseptic loosening Aseptic Aseptic loosening Aseptic Aseptic loosening Aseptic Due to stem revision stem Due to Due to stem revision stem Due to Infection Infection Infection Wear Wear Wear Wear FU 20.53 15.32 18.56 11.65 25.40 21.97 27.02 23.53 19.87 6.43 26.23 20.53 18.27 12.33 14.47 22.49 3.03 23.17 8.90 21.32 21.42

± Cup M M A M A A A A M M M A A M A A M M M M M # Defect Com Com Cav Com Cav Cav Com Com Cav Cav Cav Cav Cav Com Com Cav Cav Cav Cav Cav Com Side* L L R L L L L L L R R R R L R L L L L R R Y=yes, N=no, FU= follow-up in years FU= follow-up N=no, Y=yes, + TABLE III. III. TABLE land), Radiographic signs at time of revision of the acetabular reconstruction, showing the radiolucent lines and osteolysis per acetabular zone and the zone per acetabular lines and osteolysis the radiolucent showing reconstruction, of the acetabular signs at time of revision Radiographic loosening at time of revision. and radiographic of migration presence Case 23 Cav=Cavitary, Com=Combined, classification: AAOS to *L=left, R=right, # Defect according 21 34 41 24 17 39 42 5 3 20 26 32 37 19 27 28 10 30 6 36

97 Cemented total hip arthroplasty and impaction bone grafting in young patients

Additional reoperations and complications Since our previous update, 1 additional stem revision has been performed in the patients who 15% 22% 18% Over- estimation Over- did not undergo a revision of the acetabular reconstruction. Two other additional stems were revised with a cemented stem at time of the revision of the acetabular reconstruction. One of these patients also developed a 0.39 (0.21-0.53) 0.36 (0.17-0.51) 0.51 (0.33-0.65) 30-Year CIF 30-Year (95% Confidence Interval) cerebrovascular accident immediately post- operatively and anti-coagulation therapy was started immediately. Symptoms including the 5 paresis of his arm and leg recovered fully the 0.47 (0.31-0.67) 0.44 (0.27-0.65) 0.60 (0.44-0.77) 30-Year 1-KM 30-Year (95% Confidence Interval) following days.

Survivorship Analysis The Kaplan Meier survival of the acetabular reconstruction for the different endpoints are 18% 15% Over-estimation 14% displayed in Table IV. The Kaplan Meier survival with revision for any reason as the endpoint was 0.40 at 30 years (95% CI: 0.23-0.56) (Figure 1), so the cumulative proportion of procedures revised (1-KM) was 0.60 (95% CI: 0.44-0.77). The 0.33 (0.16-0.43) 0.26 (0.10-0.39) 0.44 (0.26-0.57) 25-Year CIF 25-Year (95% Confidence Interval) competing risk analysis showed the cumulative incidence function of revision in the presence of death (CIF) was 0.51 (95% CI: 0.33-0.65) at 30 years (Table IV). Figure 2 shows the overestimation 0.39 (0.25-0.58) 0.30 (0.17-0.50) 25-Year 1-KM 25-Year (95% Confidence Interval) 0.50 (0.35-0.68) of revision by 18% of the KM-analysis for revision for any reason after a follow-up of 30 years taking into account the competing risk of death. The Kaplan Meier survival with revision for aseptic loosening as the endpoint was 0.56 (95% CI: 0.35- TABLE IV. IV. TABLE Radio- loosening graphic Aseptic loosening Aseptic End Point End Point reason any Revision for Cumulative proportions of procedures revised (1-KM) for all acetabular reconstructions, competing risk analysis showing the cumulative the cumulative risk analysis showing competing reconstructions, (1-KM) for all acetabular proportions revised Cumulative of procedures of the 1-KM. for the 3 endpoints function and the overestimation (CIF) incidence 0.73) at 30 years, resulting in a cumulative failure

98 CHAPTER 5

Acetabular reconstructions with impaction bone-grafting and a cemented cup in patients younger than fifty years old A concise follow-up, at twenty-seven to thirty-five years, of a previous report incidence (1-KM) of 0.44. The competing risk analysis for endpoint revision for aseptic loosening showed a cumulative failure incidence of 0.36 (95% CI: 0.17-0.51) at 30 years. At time of review none of the surviving reconstructions showed complete radiographic loosening. Comparison of survival rates of primary and revision reconstructions did not show any statistically significant differences.

vision free tion r e Propo r

5

Time (years)

FIGURE 1. The Kaplan Meier survival proportion of the acetabular reconstructions (KM) for the endpoint revision for any reason.

vised

1-KM

CIF

e percentage r ulati v Cu m

Time (years)

FIGURE 2. The cumulative proportion of procedures revised (1-KM) and the competing risk analysis showing the cumulative incidence function (CIF) for all acetabular reconstructions and their upper and lower 95% confidence intervals with revision of the acetabular component for any reason as the endpoint.

99 Cemented total hip arthroplasty and impaction bone grafting in young patients

CONCLUSIONS

This long-term follow-up study has been conducted to study if the results of impaction bone grafting can be used to perform a biological repair of acetabular bone defects and hence facilitate future revisions in younger patients. We still use this acetabular bone impaction technique in complex primaries and revision surgery. Compared to our last update, 5 additional revisions have been performed, of which 3 were already reported to be radiographically loose in our last update. The survival has further declined at a reasonable constant rate over time. However, the results of 70% survival at 25 years and 56% at 30 years for endpoint revision for aseptic loosening are still acceptable19 as we used the technique in demanding primary total hip arthroplasties and acetabular revisions. As shown in other studies13, 14, 20, 21, the Kaplan Meier estimation ignores death as competing risk leading to biased estimations of the probability of 5 revision surgery. In our study, we see an overestimation of 18% for endpoint revision for any reason at 30 years follow-up. Interestingly, at current review none of the surviving implants were radiographically loose, and therefore no accelerated decline of survival is expected. Furthermore, no osteolysis was seen around these reconstructions, supporting the fact that this technique both in primary and revision reconstructions can make these reconstructions last for over 30 years. Another advantage of this technique is that in case of failure of the reconstruction, again a cemented cup and IBG can be used to perform a (re-)revision (Figure 3). In those cases we used an allograft. Technically this can be perfectly performed as the remaining bone stock after reconstruction with IBG can be used to again perform a reconstruction with cement and IBG. There are a few reports on acetabular reconstructions in younger patients, all describing a shorter duration of follow-up than we report in the current study. Kim et al2 reported a 15-year Kaplan Meier survival rate for the revised acetabular components of 93% using revision or radiological evidence of loosening of implant failures as the endpoint. Their data are comparable to our outcome at 15 years. Comba et al1 report a seven year survival of 30 acetabular revisions in patients under 55 years old, performed with impaction bone grafting and cemented cups, with need for revisions as the endpoint of 89% (CI 95% 71.9-96.4%). Lee et al3 reports the results of 181, mostly uncemented revisions (109 complete revisions), combined if necessary with use of structural and morselized allografts in 102 patients aged 50 years or younger after a mean follow-up of

100 CHAPTER 5

Acetabular reconstructions with impaction bone-grafting and a cemented cup in patients younger than fifty years old A concise follow-up, at twenty-seven to thirty-five years, of a previous report eleven years. Twenty-seven patients were lost to follow-up before minimum survival of 2 years. The 25-year survival for endpoint re-revision for any reason was 33%. To the best of our knowledge, no other studies reporting an over 25 year survival of primary and acetabular reconstructions are available. Our results support the fact that the technique of impaction bone grafting can be a reasonable long-term solution in young patients with acetabular bone defects.

5

FIGURE 3. An example of a female who received a revision reconstruction at the age of 36. At the age of 63 her reconstruction was re-revised. A) immediately post-operatieve revision reconstruction in 1985. B) pre-operative radiograph showing tilting of the cup in 2011. C) the reconstruction which has been revised in 2011 is still in situ in 2016.

101 Cemented total hip arthroplasty and impaction bone grafting in young patients

REFERENCES

1. Comba F, Buttaro M, Pusso R, Piccaluga F. Acetabular revision surgery with impacted bone allografts and cemented cups in patients younger than 55 years. Int Orthop. 2009 Jun;33(3):611-6. 2. Kim YH, Park JW, Kim JS. Isolated revision of an acetabular component to a ceramic-on- ceramic bearing in patients under 50 years of age. Bone Joint J. 2015 Sep;97-B(9):1197-203. 3. Lee PT, Lakstein DL, Lozano B, Safir O, Backstein J, Gross AE. Mid-to long-term results of revision total hip replacement in patients aged 50 years or younger. Bone Joint J. 2014 Aug;96-B(8):1047-51. 4. Busch VJ, Gardeniers JW, Verdonschot N, Slooff TJ, Schreurs BW. Acetabular reconstruction with impaction bone-grafting and a cemented cup in patients younger than fifty years old: a concise follow-up, at twenty to twenty-eight years, of a previous report. J Bone Joint Surg Am. 5 2011 Feb 16;93(4):367-71. 5. Schreurs BW, Busch VJ, Welten ML, Verdonschot N, Slooff TJ, Gardeniers JW. Acetabular reconstruction with impaction bone-grafting and a cemented cup in patients younger than fifty years old. J Bone Joint Surg Am. 2004 Nov;86-A(11):2385-92. 6. D’Antonio JA, Capello WN, Borden LS, Bargar WL, Bierbaum BF, Boettcher WG, et al. Classification and management of acetabular abnormalities in total hip arthroplasty. Clin Orthop Relat Res. 1989 Jun(243):126-37. 7. Conn RA PL, Stauffer RN, Ilstrup DM. Management of acetabular deficiency; long-term results of bone-grafting the acetabulum in total hip arthroplasty. Orthop Trans 1985;9:451-2. 8. DeLee JG, Charnley J. Radiological demarcation of cemented sockets in total hip replacement. Clin Orthop Relat Res. 1976 Nov-Dec(121):20-32. 9. Brooker AF, Bowerman JW, Robinson RA, Riley LH, Jr. Ectopic ossification following total hip replacement. Incidence and a method of classification. J Bone Joint Surg Am. 1973 Dec;55(8):1629-32. 10. Livermore J, Ilstrup D, Morrey B. Effect of femoral head size on wear of the polyethylene acetabular component. J Bone Joint Surg Am. 1990 Apr;72(4):518-28. 11. Dawson J, Fitzpatrick R, Carr A, Murray D. Questionnaire on the perceptions of patients about total hip replacement. J Bone Joint Surg Br. 1996 Mar;78(2):185-90.

102 CHAPTER 5

Acetabular reconstructions with impaction bone-grafting and a cemented cup in patients younger than fifty years old A concise follow-up, at twenty-seven to thirty-five years, of a previous report

12. Gooley TA, Leisenring W, Crowley J, Storer BE. Estimation of failure probabilities in the presence of competing risks: new representations of old estimators. Stat Med. 1999 Mar 30;18(6):695-706. 13. Keurentjes JC, Fiocco M, Schreurs BW, Pijls BG, Nouta KA, Nelissen RG. Revision surgery is overestimated in hip replacement. Bone Joint Res. 2012 Oct;1(10):258-62. 14. Fennema P, Lubsen J. Survival analysis in total joint replacement: an alternative method of accounting for the presence of competing risk. J Bone Joint Surg Br. 2010 May;92(5):701-6. 15. Putter H, Fiocco M, Geskus RB. Tutorial in biostatistics: competing risks and multi-state models. Stat Med. 2007 May 20;26(11):2389-430. 16. Gray B. cmprsk: Subdistribution Analysis of Competing Risks. R package version 2.2-7. 2014 [10th of March 2016]; Available from: https://CRAN.R-project.org/package=cmprsk. 17. Jr FEH. rms: Regression Modeling Strategies. R package version 4.4-2. 2016 [10th of March 2016]; Available from: https://CRAN.R-project.org/package=rms. 18. Team RC. R: A language and environment for statistical computing. R Foundation for 5 Statistical Computing, Vienna, Austria. 2016 [10th of March 2016]; Available from: https:// www.R-project.org/. 19. Keener JD, Callaghan JJ, Goetz DD, Pederson DR, Sullivan PM, Johnston RC. Twenty-five- year results after Charnley total hip arthroplasty in patients less than fifty years old: a concise follow-up of a previous report. J Bone Joint Surg Am. 2003 Jun;85-A(6):1066-72. 20. Gillam MH, Ryan P, Graves SE, Miller LN, de Steiger RN, Salter A. Competing risks survival analysis applied to data from the Australian Orthopaedic Association National Joint Replacement Registry. Acta Orthop. 2010 Oct;81(5):548-55. 21. Te Stroet MA, Keurentjes JC, Rijnen WH, Gardeniers JW, Verdonschot N, Slooff TJ, et al. Acetabular revision with impaction bone grafting and a cemented polyethylene acetabular component: comparison of the Kaplan-Meier analysis to the competing risk analysis in 62 revisions with 25 to 30 years follow-up. Bone Joint J. 2015 Oct;97-B(10):1338-44.

103

Clinical and radiological outcome of the cemented Contemporary acetabular component in patients < 50 years of age

Marloes W.J.L. Schmitz, Carla Timmer, Wim H.C. Rijnen,

Jean W.M. Gardeniers, B. Willem Schreurs

Bone Joint J 2013;95-B:1617–25.

CHAPTER 6 Cemented total hip arthroplasty and impaction bone grafting in young patients

ABSTRACT

Despite the worldwide usage of the cemented Contemporary acetabular component (Stryker), no published data are available regarding its use in patients aged < 50 years. We undertook a mid- to long-term follow-up study, including all consecutive patients aged < 50 years who underwent a primary total hip replacement using the Contemporary acetabular component with the Exeter cemented stem between January 1999 and January 2006. There were 152 hips in 126 patients, 61 men and 65 women, mean age at surgery 37.6 years (16 to 49 yrs). One patient was lost to follow-up. Mean clinical follow-up of all implants was 7.6 years (0.9 to 12.0). All clinical questionnaire scores, including Harris hip score, Oxford hip score and several visual analogue scales, were found to have improved. The eight year survivorship of all acetabular components for the endpoints revision for any reason or revision for 6 aseptic loosening was 94.4% (95% CI: 89.2-97.2) and 96.4% (95% CI: 91.6-98.5), respectively. Radiological follow-up was complete for 146 implants. The eight year survival for the endpoint radiological loosening was 93.1% (95% CI: 86.2-96.6). Three surviving implants were considered radiologically loose but were asymptomatic. The presence of acetabular osteolysis (n = 17, 11.8%) and radiolucent lines (n = 20, 13.9%) in the 144 surviving cups indicates a need for continued observation in the second decade of follow-up in order to observe their influence on long-term survival. The clinical and radiological data resulting in a ten-year survival rate > 90% in young patients support the use of the Contemporary acetabular component in this specific patient group.

106 CHAPTER 6

Clinical and radiological outcome of the cemented Contemporary acetabular component in patients < 50 years of age

The results of cemented primary total hip replacement (THR) have been excellent over the recent decades, with national joint registries reporting revision-free survival rates between 90% and 98.2% at ten years.1-3 In addition, Callaghan et al4 described a survival rate of 88% for cemented Charnley (Thackray Limited, Leeds, UK) THRs after 30 years. Unfortunately, in patients aged < 50 years results have been less encouraging. This has created a shift towards uncemented designs and the use of other bearings in this group of patients.5 However, based on recent long- term results of cemented THR using modern cementing techniques,6-8 and the unexpected and ongoing problems with metal-on- metal articulations,9 the discussion regarding hip replacement in this group of young patients has been re-opened. In particular the authors suggest that in current orthopaedic practice, attention has been drawn to the importance of surveillance of newly introduced implants, as well as ongoing long-term results of implants that are currently in use all over the world. The cemented Contemporary acetabular component (Stryker-Howmedica, Newbury, United Kingdom), which has been available for nearly 20 years, has been used in young patients at our institution for over 15 years. Registry data reveal it to be a commonly used 6 component in primary THR over the last decade.1-3,10 The registries of England and Wales, Australia, and New Zealand report a cumulative revision rate of the Contemporary acetabular component of 6.1% (95% CI: 4.4-8.5) after ten years,10 of 1.26% (95% CI: 1.10-1.44) at five years1 and a revision rate per 100 component-years of 0.64 (95% CI: 0.56-0.73), respectively.3 The Danish and Swedish registries found the survival rate of this acetabular component to be 96.0% (95% CI: 95.2- 96.8) at five years11 and 97.3% (95% CI: 95.3-99.3) at six years, respectively.2 There are no reports of ten-year survival, radiological and clinical outcomes of the Contemporary component in primary THR in young patients. We report the mid-term clinical and radiological results of this device in primary THR in patients aged < 50 years.

107 Cemented total hip arthroplasty and impaction bone grafting in young patients

PATIENTS AND METHODS

Conventionally our department performs cemented THR regardless of the patients’ age. Between January 1999 and January 2006, all consecutive patients aged < 50 years undergoing primary THR received the Contemporary acetabular component. In total, 152 such components were used as part of a primary THR in 126 consecutive patients, of whom 61 (48.4%) were men. The mean age at operation was 37.6 years (16 to 49). There were 73 THRs (48.0%) inserted on the right side and 26 patients had a bilateral procedure. The mean body mass index (BMI) was 25.5 kg/m2 (15.2 to 42.0). The primary indications in the majority of cases were developmental dysplasia of the hip (n = 33 hips, 21.7%) and corticosteroid induced avascular necrosis (n = 29 hips, 19.1%) (Table I). Only THRs performed for oncological reasons were excluded.

TABLE I. Indications for primary total hip replacement. Indications N (%) 6 SOA due to CHD 33 21.7 Corticosteroid induced AVN 29 19.1

Primary osteoarthritis 15 9.9

SOA due to rheumatoid arthritis 11 7.2

SOA due to Perthes’ disease 11 7.2

SOA due to epiphyseal dysplasia 9 5.9

Posttraumatic osteoarthritis 8 5.3

AVN of unknown origin 6 3.9

SOA due to ankylosing spondylitis 5 3.3

Neonatal septic coxitis 5 3.3

Epiphysiolysis 5 3.3

SOA due to posttraumatic AVN 4 2.6

Morquio’s disease 4 2.6

Polycystic hip disease 2 1.3

Osteogenesis imperfecta 2 1.3

SOA due to protrusio acetabuli 1 0.7

Alcohol induced AVN 1 0.7

Pigmented villonodular synovitis 1 0.7

Total 152 100.0 SOA: secondary osteoarthritis, CHD: congenital hip dysplasia, AVN: avascular necrosis

108 CHAPTER 6

Clinical and radiological outcome of the cemented Contemporary acetabular component in patients < 50 years of age

The cemented Contemporary acetabular component has four PMMA cement spacers which are intended to ensure a cement mantle of 2 mm to 3mm,12 and is available in a hooded and flanged version. We used a hooded device in 126 (82.9%) THR and a flanged version in 26 (17.1%). The component was manufactured from ultra high molecular weight polyethylene (UHMWPE) and combined in all cases with the cemented Exeter femoral stem (Stryker-How- medica). In 2001, the morse taper of the Exeter stem was changed, resulting in a cemented Exeter stem with a conventional trunnion being used in 40 hips and a V40 trunnion in 112 hips. Only 28 mm diameter metal heads were used to match the 28 mm inner diameter of the acetabular component; the median outer diameter was 52 mm (48 to 60). The posterolateral approach was used in all cases, with the operations performed by senior orthopaedic surgeons (JWMG, BWS). Deficiencies in acetabular bone stock were present in 63 hips (41.4%) and classified according to the classification of the American Academy of Orthopaedic Surgeons.13 There were 16 segmental defects, 25 cavitary defects and 22 combined deficiencies. All defects were reconstructed with impaction bone-grafting (IBG)14 using an autograft in 49 cases, an allograft in four and a combination of an auto- and an allo- graft in ten hips. 6 Wire meshes were used in 41 hips (27.0%). Components were implanted using a third generation technique including optimal cement preparation, pulsatile lavage, pressurising and the use of spacer to guarantee an even cement mantle thickness and antibiotic loaded cement (Surgical Simplex; Stryker- Howmedica). The mean operating time was 128 minutes (65 to 320) and mean length of stay after THR was 11.4 days (5 to 33). Each patient received 2 g intravenous cefazolin as antibiotic prophylaxis pre-operatively. Post-operatively, patients were treated with subcutaneous low-molecular-weight heparin for six weeks. In order to prevent heterotopic ossification, non-steroidal anti-inflammatory drugs (NSAIDs) were used during the first post-operative week. When NSAIDs were contraindicated, patients received a single dose of 7 Gy radiation pre- operatively. Clinical and radiological data were collected prospectively at routine review at six weeks, three and six months and one year after surgery. Follow-up visits were annually or biannually. Patients who were unable to attend for follow-up had radiographs taken in another hospital, which were sent to our institution for analysis. Anteroposterior (AP) radiographs of the pelvis were evaluated on a consensus basis by three authors (MWJLS, CT and BWS). Evaluation of the radiographs included loosening of the

109 Cemented total hip arthroplasty and impaction bone grafting in young patients

acetabular component, osteolysis and radiolucent lines (RLLs), component migration, cysts, fractures, tilting of the component, polyethylene wear and the presence of hetero- topic ossification. Loosening was defined as migration > 5 mm or tilting of the implant > 5°, both measured in relation to the inter-teardrop line.15 RLLs with a demarcation > 2 mm were recorded. Osteolysis and RLLs were assessed according to the zones described by DeLee and Charnley16 for the acetabular component. Periarticular ossifications were classified according to Brooker et al.17 Linear wear was calculated using the method of Dorr and Wan.18 Clinical and functional evaluation was performed by independent researchers at our outpatient clinic. This included the Harris hip score (HHS),19 Oxford hip score (OHS),20 and visual analogue scales for pain at rest (VAS rest) and during physical activity (VAS activity). The VAS scale ranged from 0 (no pain) to 100 (unbearable pain). A VAS for satisfaction was also included (VAS satisfaction) ranging from 0 (not satisfied at all) to 100 (complete satisfaction).21

6 Statistical Analysis Kaplan–Meier survival analyses with 95% confidence intervals (CIs) were performed for all acetabular components, with end-points including revision for any reason, revision for aseptic loosening, revision for septic loosening and survival up to the identification of radiological loosening. We also calculated a worst-case scenario, defining revision, lost to follow-up or radiological failure as a collective endpoint. Time to revision was defined as the time between the date of implantation of the THR and the date of revision. Patients without revision were censored at the date of the last radiological or clinical follow-up or at death. To indicate significant differences in survival between groups we used the log- rank test. A linear model was used to assess whether the HHS and OHS scores differed between patients with a surviving implant and patients with a revision. All calculations were made with SPSS v18.0.2 (SPSS Inc., Chicago, Illinois) and SAS v9.2 (SAS Institute Inc, Cary, North Carolina). A p-value < 0.05 was considered significant.

110 CHAPTER 6

Clinical and radiological outcome of the cemented Contemporary acetabular component in patients < 50 years of age

RESULTS

During follow-up, nine patients (13 hips) died at a mean follow-up of 4.2 years (1.1 to 7.8) for reasons not related to the THR and none of them had required revision of their THR. These patients had all been followed up to the point of their death and so their data are included. Mean clinical follow-up of all acetabular components (n = 152) was 7.6 years (0.9 to 12.0). Three patients (six hips) had no recent radiograph. One patient (two hips) was lost to follow-up after 3.6 years with a radiological follow-up of only one month. The second patient was pregnant at the time of review and had a clinically well- functioning prosthesis, whereas the third patient agreed to visit our outpatient clinic but did not attend her appointment. On telephone interview she had no complaints regarding her hip prosthesis. Their most recent available radiographs were used in the radiological evaluation. The median pre- and post-operative available HHS, OHS and VAS scores after median follow-up are illustrated in Table II. Post-operative complications, excluding those resulting in revision, are listed in Table III. In total, 18 post-operative complications were 6 seen in 16 patients, of which seven resulted in surgical intervention. One periprosthetic fracture occurred in femoral Gruen zone I 6.4 years after primary THR.22 The fracture was secured with a plate and cerclage wires and the patient was functioning well at final follow-up, 3.5 years after fixation of the fracture. Overall, eight hips had one or recurrent dislocations resulting in a dislocation rate of 5.3%. No venous thromboembolic (VTE) complications were noted.

TABLE II. Pre- and post-operative Harris hip score (HHS), Oxford hip score (OHS) and visual analogue scales (VAS) for pain at rest, pain during activity and satisfaction. Based on all available scores of patients up to their last visit or revision of their acetabular component. Median score (Range)

Preoperative scores N Postoperative scores N Follow-up in years

HHS 51 (15 to 81) 73 94 (41 to 100) 149 6 (0.3 to12)

OHS 38 (24 to 57) 59 16 (12 to 49) 149 6.5 (0.5 to12)

VAS rest 45 (0 to 100) 59 0 (0 to 90) 150 7 (0.5 to12)

VAS activity 72 (18 to 100) 59 75 (0 to 100) 150 7 (0.5 to 12)

VAS satisfaction 11 (0 to 50) 42 90 (10 to 100) 145 6.3 (0.5 to 12)

HHS: Harris Hip Score, OHS: Oxford Hip Score, VAS: Visual Analogue Scale

111 Cemented total hip arthroplasty and impaction bone grafting in young patients

TABLE III. Post-operative complications, excluding complications leading to revision Complication N

Complications requiring surgery

Permanent femoral nerve palsy 1

Peri-prosthetic fracture 1

Recurrent dislocation 1

Fascia repair 1

Debridement of excess cement 1

Removal of heterotopic ossifications 1

Debridement under suspicion of deep infection, negative for infection 1

Complications not requiring surgery

Urinary tract infection 1*

Post-operative haematoma 1†

Single dislocation 2*

Recurrent dislocation 2

Retention bladder 1 6 Pneumonia 1† Haemolysis 1

Complaints of pain, recovering fully 1

Transient sensory obturator nerve palsy 1 *One patient had a urinary tract infection and a single dislocation. † One patient had a post-operative haematoma and developed a pneumonia post-operatively.

A total of eight acetabular components were subsequently revised: five due to aseptic loosening after 1.1, 2.5, 3.1, 5.0 and 6.0 years post-operatively, respectively. One hooded implant was revised for recurrent subluxation at 3.5 years and one acetabular component showed loosening after 4.3 years following trauma. One hooded implant without IBG was revised as part of a complete revision for septic loosening at 0.9 years. One further stem was revised for septic loosening without removal of the acetabular component after 5.6 years, despite this partial revision the infection could be cured. Two modular femoral heads were exchanged following recurrent subluxations one week and one month after surgery, respectively. No stems were revised for aseptic loosening.

112 CHAPTER 6

Clinical and radiological outcome of the cemented Contemporary acetabular component in patients < 50 years of age

TABLE IV. Radiological evaluation of the surviving acetabular components, based on their last available radiograph, and revised implants, based on their last radiograph before revision. Surviving implants (n=144) Revised implants (n=8) Stable Radiologically loose Stable Radiologically loose Total (n=152) 141 3 3 5 Radiolucent lines Immeasurable 0 0 0 1 None 123 1 1 1 Yes 18 2 2 3 Zone(s) I 9 0 1 0 II 2 0 0 0 III 3 0 1 0 I + II 1 0 0 0 II + III 2 0 0 0 I + III 1 0 0 0 I + II + III 0 2* 0 3† Stability Progressive 8 1 1 2 Stable 10 1 1 1

Osteolysis None 124 3 3 5 Yes 17 0 0 0 Zone(s) 6 Zone I 9 0 0 0 Zone II 2 0 0 0 Zone III 4 0 0 0 Zone I + II 1 0 0 0 Zone II + III 1 0 0 0

Cysts None 140 3 3 5 Yes (zone II) 1 0 0 0

Migration >5mm Immeasurable 0 0 0 1 No 141 3 3 3 Yes 0 0 0 1†

Wear Immeasurable 6 0 0 2 <2mm 130 2 3 2 >2mm 5 1 0 1

Tilting <5° 141 1 3 2 > 5° 0 2* 0 3†

Periarticular ossifications None 102 3 3 4 Brooker grade I 26 0 0 1 Brooker grade II 8 0 0 0 Brooker grade III 5 0 0 0 Brooker grade IV 0 0 0 0 * One component showed lines in all three zones and tilting. † One cup showed lines in all three zones, migration and tilting.

113 Cemented total hip arthroplasty and impaction bone grafting in young patients

Radiographs of all 144 surviving acetabular components, including three hips with an incomplete follow-up, were available for review. Due to extensive acetabular reconstructions using metal meshes, linear wear could not be measured accurately in six hips. A typical case is shown in Figure 1. A total of three surviving acetabular components were considered radiologically loose after 1.4, 7.8 and 8.0 years of follow-up (Table IV). These patients were clinically asymptomatic and functioning well after 8.3, 11.0 and 8.9 years, respectively.

6

FIGURE 1. Anteroposterior pelvic radiograph of a man with Perthes’ disease, treated with several osteotomies of the femur and pelvis, including a Chiari osteotomy, before receiving a THA with a Contemporary cup at the age of 30. At final follow-up, 6.6 years post-surgery, we were unable to determine whether wear was present, due to a superolateral rim defect that was reconstructed with IBG and a rim mesh.

114 CHAPTER 6

Clinical and radiological outcome of the cemented Contemporary acetabular component in patients < 50 years of age

An example of a radiologically stable, surviving acetabular component is shown in Figure 2. Of the 141 surviving stable implants, 18 (12.8%) showed RLLs, most frequently in zone I (Table IV). All lines emerged in the interface between bone and cement. All grafts were fully incorporated. UHMWPE wear of more than 2 mm was present in five out of 130 hips (3.8%) (Table IV). These five hips had a mean radiological follow-up of 9.1 years (8.0 to 10.6).

FIGURE 2. A 43-year old female with developmental dysplasia of the left hip. Preoperative AP radiograph 6 (a), two months post-operative AP radiograph (b) showing the THA with Contemporary cup and 10 years post-operatively (c) with no signs of radiographic loosening or wear of the cup.

At time of revision, five out of eight revised acetabular components were considered radiologically loose after 2.2, 2.4, 2.8, 2.9 and 4.3 years. Results of radiological evaluation at time of revision can be found in Table IV. Kaplan–Meier survivorship of the Contemporary acetabular components with revision for any reason as the endpoint was 94.4% (95% CI: 89.2-97.2) at eight years, survivorship for aseptic loosening was 96.4% (95% CI: 91.6-98.5) (Fig. 3). The eight-year survival was 93.1% (95% CI: 86.2-96.6) with radiological loosening of the acetabular component as the endpoint (Fig. 3). Survival with revision for aseptic loosening at five years was 97.6% (95% CI: 92.6- 99.2) for the hooded and 100% (95% CI: 86.7-100) for the flanged implants (Table V). However, this difference in survival was not significantly different (log rank, p = 0.332). Survivorship with revision for aseptic loosening was 98.5% (95% CI: 89.6- 99.8) for the components implanted with IBG and 94.8% (95% CI: 86.8-98.0) for those implanted in the absence of IBG at eight years. This difference in survival between the two groups was not statistically significant either (log-rank, p = 0.270).

115 Cemented total hip arthroplasty and impaction bone grafting in young patients

00

0

0 SURVIVAL % ANY REASON % ANY SURVIVAL

0 5 6 0 n5 5 5 YEARS POST SURGERY

00

0

6 0 SURVIVAL % ASEPTIC LOOSENING SURVIVAL

0 5 6 0 n5 5 5 YEARS POST SURGERY 00

0

0 SURVIVAL % RADIOGRAPHIC LOOSENING SURVIVAL

0 5 6 0 n5 6 5 YEARS POST SURGERY

FIGURE 3. Survival curves with asymmetrical 95% confidence-intervals for the endpoints revision for any reason (a), revision for aseptic loosening (b) and radiographic loosening (c).

116 CHAPTER 6

Clinical and radiological outcome of the cemented Contemporary acetabular component in patients < 50 years of age

TABLE V. Survival for all Contemporary components (n=152), and the flanged (n=26) and hooded (n=126) implants separately, for different endpoints, including a worst case scenario (NE, not estimable). Survival (%, 95% CI) 5 years (%) 8 years (%) 5 years 8 years Flanged Hooded Flanged Hooded Revision for any 95.9% 94.4% 100.0% 95.1% NE 93.4% reason (91.2-98.2) (89.2-97.2) (86.7-100.0) (89.5-97.8) (87.2-96.6) Number 135 71 21 114 70

Revision for 98.0% 96.4% 100.0% 97.6% NE 95.8% aseptic loosening (93.8-99.3) (91.6-98.5) (86.7-100.0) (92.6-99.2) (90.1-98.2) Number 135 71 21 114 70

Revision for 99.3% 99.3% 100.0% 99.2% NE 99.2% septic loosening (95.4-99.9) (95.4-99.9) (86.7-100.0) (94.5-99.9) (94.5-99.9) Number 135 71 21 114 70

Radiographic 95.7% 93.1% 96.0% 95.7% NE 93.1% loosening (90.7-98.0) (86.2-96.6) (74.8-99.4) (90.0-98.2) (85.8-96.7) Number 124 68 17 107 68

Worst case scenario* 93.1% 89.9% 96.0% 92.6% NE 89.3% (87.6-96.2) (82.8-94.1) (74.8-99.4) (86.3-96.1) (81.6-93.8) n=68 6 Number 125 68 17 108 68 * worst case scenario represents all the acetabular component failures, including radiological failures and the patient lost to follow-up (two hips).

DISCUSSION

Our study shows that very good results in young patients can be obtained by using the cemented Contemporary UHMWPE acetabular component. The eight-year survivorship with the endpoint revision for aseptic loosening for the entire cohort was 96.4% (95% CI 91.6-98.5). These survival rates are similar to those reported by registries (Table VI),1,2,10,11 but these do not enable comparisons based on age, radiological results or clinical outcomes such as the HHS, OHS and VAS scores. Therefore, we compared our results with different cohort studies that also used some of these widely used acetabular components.23-26 Studies reporting the mid- to long-term survival of these implants are summarised in Table VII.27-29 Overall, these results are comparable with the current results of the

117 Cemented total hip arthroplasty and impaction bone grafting in young patients

Contemporary acetabular component, whilst the primary indications for the THR and reasons for revisions in these studies are varied. The calculated survival rates in our cohort of young patients are very satisfying, especially considering that younger patients generally have lower survival rates compared with elderly patients.1,3,10,30,31

TABLE VI. Comparison of data on widely used cups in several national joint registries. Implant Registry/Rate Trident Pinnacle Birmingham Contemporary Hip Resurfacing Denmark12 Number used in 2010 363 1880 72 302 5-year survival rate (95%CI) 97.6 (96.4 to 98.8) * 95.6 (94.6 to 96.6) † - 96.0 (95.2 to 96.8) ‡

New Zealand3 Number used in 2010 606 1363 - 379 Revision rate/100 compo- 0.66 (0.57 to 0.76) 0.87 (0.71 to 1.06) 1.46 (0.67 to 2.78) 0.64 (0.56 to 0.73) nent-years (95% CI)

6 Sweden2 Number used in 2010 201 130† 137 7993‡ Survival rate (95%CI) 97.9 (96.8 to 98.9) - 97.8 (95.3 to 100) at 97.3 (95.3 to 99.3) at 6 years 9 years at 6 years

England and Wales 11 Number used in 2010 NA NA NA NA 5-year revision rate 2.35 (1.83 to 3.02) * 2.29 (2.04 to 2.57) † 3.44 (3.12 to 3.79) 1.26 (1.10 to 1.44) ¶

Australia1 Number used in 2010 6106 5059 587 289 (hooded); 380 (Flanged) 10- year cumulative 4.2 (3.8 to 4.7) 6.3 (5.3 to 7.4) 6.1 (4.4 to 8.5); proportion revised 7.3 (4.5 to 12.0) * combined with Symax stem † combined with Corail stem ‡ combined with Exeter stem § combined with Accolade stem ¶combined with Exeter V40 stem

118 CHAPTER 6

Clinical and radiological outcome of the cemented Contemporary acetabular component in patients < 50 years of age

TABLE VII. Comparison of results of the current study with cohort studies reporting survival rates of other widely used acetabular designs. Implant/Study† Characteristics* Trident29 Pinnacle27 BHR29 Contemporary (current study) Hips 209 95 3095 152 Mean follow-up (yrs) (range) 4.2 6 8 (0.7 to 13) 7.6 (0.9 to 12.0) Mean age (yrs) (range) 52 53.5 (34 to 70) 53 (13 to 86) 37.6 (16 to 49) Mean BMI (kg/m2) (Range) - 29.3 (19.5 to 45.9) - 25.5 (15.2 to 42.0)

Indication (%) OA 81 91.6 100 9.9 AVN 11 4.2 - 23.7 CHD - 1.1 - 21.7 RA - 2.1 - 7.2 Other 7.5 1.1 - 37.5

Survival any reason 98.1% (96.2-99.9) 100% 96% 94.4% (89.2 to 97.2) at 5 years at 7 years at 13 years at 8 years Main reasons for revision Recurrent sublux- - Femoral head Aseptic loosening ations (n=2) collapse (n=25) (n=5) 6

Osteolysis (%) No osteolysis No osteolysis - 11.8 Radiolucent lines (%) 1.7% - - 13.9 PAO - - 15.3 27.0 Mean Harris hip score (range) pre-operatively - 43.4 (20-68) - 51 (15-81) post-operatively 96.6 98.3 (86-100) - (41-100) *BMI, body mass index; OA, osteoarthritis: AVN, avascular necrosis; CHD, congenital hip dysplasia; RA, reumatoid arthritis; PAO, periarticular ossification †BHR: Birmingham Hip Resurfacing

The most common radiological signs seen in our cohort were peri-articular ossification (n = 39, 27.0%), acetabular osteolysis (n = 17, 11.8%) and RLLs (n = 20, 13.9%) in the surviving cups. D’Antonio et al29 and Kindsfater et al27 reported no osteolysis, and only D’Antonio et al29 mentioned RLLs in their study, with an incidence of 1.7%. A possible explanation for their low numbers was the strict inclusion criteria that they applied, as patients with a bone stock deficiency or using corticosteroids were excluded. Peri- articular ossification was reported only by McMinn et al28 in 15.3% of cases. Other studies,

119 Cemented total hip arthroplasty and impaction bone grafting in young patients

specifically in young patients, found osteolysis ranging from 0% to 34%, and RLLs in 7% to 47% of the acetabular components.7,32-35 These wide ranges illustrate the difficulties in comparing radiological outcomes, which may reflect not only differences in component designs but also the application of different criteria for reporting RLLs or osteolysis. We acknowledge that in young patients the outcome of the acetabular components in another ten years will be crucial, as RLLs and osteolysis might eventually progress to loosening. However, other cohorts of young patients have shown that the early signs of radiological failure do not inevitably result in impaired function or revision in their second decade.36,37 Our study does not specifically assess high level function in young patients but pre- and post-operative HHS and OHS scores are similar to that reported by several cohort studies (Table VI).7,25-27,29,33-35 The Australian registry reported a cumulative revision rate at ten years of 6.1% (95% CI 4.4-8.5) for the Contemporary hooded, and 7.3% (95% CI 4.5-12.0) for the flanged implant.1 Our ten-year survival rate of the Contemporary hooded component of 93.4% is comparable (n at risk = 25), and this is satisfying considering the young age of the patients 6 in our cohort. Because of the short follow-up and low numbers of Contemporary flanged components (n = 26) we were not able to calculate a representative survivorship after five years for this design, although there were no revisions in this group so far. The flanged implant was an evolutionary development that could improve cement penetration and reduce the incidence of loosening. At the same time it became apparent that a hooded implant might be associated with higher dislocation rates due to its design as described by Jameson et al.38 The hood consists of a large posterior elevation of the rim, intuitively intended to reduce the risk of posterior dislocation but in practice functioning as a source of impingement, resulting in a relatively high rate of dislocation, including anteriorly. Our department has since switched to the use of the Contemporary flanged component, due to the dislocation rate of 5.6% in the 126 hooded implants. At the time of our analysis the dislocation rate in our cohort did not differ significantly between the flanged and hooded implants. Analysis should however, ideally be performed for both designs separately, but our numbers did not allow this in any meaningful way on this occasion. A limitation of the current study might be the diagnostic heterogeneity of our group, making it difficult to compare our data with other studies. Despite the variety of indications, we report a high survival rate of the acetabular component, which is often the weakest link of the THR in young patients.5 Another limitation was the difficulty of the

120 CHAPTER 6

Clinical and radiological outcome of the cemented Contemporary acetabular component in patients < 50 years of age radiological evaluation of a number of hips that had required an extensive reconstruction of the acetabulum with IBG. The Contemporary acetabular implant shows good results in our cohort of young patients. With revision for aseptic loosening as endpoint the survival rate was 96.4% (95% CI 91.6-98.5) at eight years in this challenging group of 126 consecutive patients aged < 50 years. The clinical outcome of our patients is similar to that of other widely used THRs in several national joint registries and cohort studies, and those of other cohort studies with young patients. We believe the long-term clinical and radiological results, showing a ten-year survival of more than 90% in patients below 50 years of age, support the use of the cemented Contemporary acetabular component in this specific patient group.

6

121 Cemented total hip arthroplasty and impaction bone grafting in young patients

REFERENCES

1. No authors listed. Australian Orthopaedic Association National Joint Replacement Registry: Annual Report 2011. https://aoanjrr.dmac.adelaide.edu.au/annual-reports- 2011 (date last accessed 15 August 2013). 2. No authors listed. Swedish Hip Arthroplasty Register Annual Report 2010. http:// www.shpr. se/Libraries/Documents/AnnualReport-2010-2-eng.sflb.ashx (date last accessed 15 August 2013). 3. No authors listed. New Zealand Orthopeadic Association. The New Zealand Joint Registry, thirteen year report, 1999-2010. http://www.cdhb.govt.nz/njr/reports/ A2D65CA3.pdf (date last accessed 15 August 2013). 4. Callaghan JJ, Templeton JE, Liu SS, et al. Results of Charnley total hip arthro- plasty at a minimum of thirty years: a concise follow-up of a previous report. J Bone Joint Surg [Am] 2004;86-A:690–695. 5. De Kam DC, Busch VJ, Veth RP, Schreurs BW. Total hip arthroplasties in young patients 6 under 50 years: limited evidence for current trends: a descriptive literature review. Hip Int 2011;21:518–525. 6. Eskelinen A, Remes V, Helenius I, et al. Total hip arthroplasty for primary osteo- arthrosis in younger patients in the Finnish arthroplasty register. 4,661 primary replacements followed for 0-22 years. Acta Orthop 2005;76:28–41. 7. Lewthwaite SC, Squires B, Gie GA, Timperley AJ, Ling RS. The Exeter Universal hip in patients 50 years or younger at 10-17 years’ followup. Clin Orthop Relat Res 2008;466-2:324–331. 8. Morshed S, Bozic KJ, Ries MD, Malchau H, Colford JM Jr. Comparison of cemented and uncemented fixation in total hip replacement: a meta-analysis. Acta Orthop 2007;78:315–326. 9. Heneghan C, Langton D, Thompson M. Ongoing problems with metal-on-metal hip implants. BMJ 2012;344:1349. 10. No authors listed. National Joint Registry for England and Wales: 8th annual report 2011. http://www.njrcentre.org.uk (date last accessed 15 August 2013). 11. No authors listed. Dansk Hoftealloplastik Register Årsrapport 2011. http:// www.dhr.dk/ Ny%20mappe/rapporter/DHR%20Aarsrapport_2011%20t_web.pdf (date last accessed 15 August 2013). 12. Lichtinger TK, Müller RT. Improvement of the cement mantle of the acetabular component with bone cement spacers: a retrospective analysis of 200 cemented cups. Arch Orthop Trauma Surg 1998;118:75–77.

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Clinical and radiological outcome of the cemented Contemporary acetabular component in patients < 50 years of age

13. D’Antonio JA, Capello WN, Borden LS, et al. Classification and management of acetabular abnormalities in total hip arthroplasty. Clin Orthop Relat Res 1989;243:126–137. 14. Schreurs BW, Slooff TJ, Gardeniers JW, Buma P. Acetabular reconstruction with bone impaction grafting and a cemented cup: 20 years’ experience. Clin Orthop Relat Res 2001;393:202–215. 15. Goodman SB, Adler SJ, Fyhrie DP, Schurman DJ. The acetabular teardrop and its relevance to acetabular migration. Clin Orthop Relat Res 1988;236:199–204. 16. DeLee JG, Charnley J. Radiological demarcation of cemented sockets in total hip replacement. Clin Orthop Relat Res 1976;121:20–32. 17. Brooker AF, Bowerman JW, Robinson RA, Riley LH Jr. Ectopic ossification fol- lowing total hip replacement: incidence and a method of classification.J Bone Joint Surg [Am] 1973;55:1629–1632. 18. Dorr LD, Wan Z. Comparative results of a distal modular sleeve, circumferential coating, and stiffness relief using the Anatomic Porous Replacement II. J Arthroplasty 1996;11:419–428. 19. Harris WH. Traumatic arthritis of the hip after dislocation and acetabular fractures: treatment by mold arthroplasty: an end-result study using a new method of result evaluation. J Bone Joint Surg [Am] 1969;51-A:737–755. 6 20. Dawson J, Fitzpatrick R, Carr A, Murray D. Questionnaire on the perceptions of patients about total hip replacement. J Bone Joint Surg [Br] 1996;78-B:185–190. 21. Brokelman RB, Haverkamp D, van Loon C, et al. The validation of the visual ana- logue scale for patient satisfaction after total hip arthroplasty. Eur Orthop Traumatol 2012;3:101–105. 22. Gruen TA, McNeice GM, Amstutz HC. “Modes of failure” of cemented stem-type femoral components: a radiographic analysis of loosening. Clin Orthop Relat Res 1979;141:17–27. 23. Engh CA, Hopper RH Jr, Engh CA Jr. Long-term porous-coated cup survivorship using spikes, screws, and press-fitting for initial fixation. J Arthroplasty 2004;19(Suppl):54–60. 24. Holland JP, Langton DJ, Hashmi M. Ten-year clinical, radiological and metal ion analysis of the Birmingham Hip Resurfacing: from a single, non-designer surgeon. J Bone Joint Surg [Br] 2012;94-B:471–476. 25. Coulter G, Young DA, Dalziel RE, Shimmin AJ. Birmingham hip resurfacing at a mean of ten years: results from an independent centre. J Bone Joint Surg [Br] 2012;94-B:315–321. 26. Treacy RB, McBryde CW, Shears E, Pynsent PB. Birmingham hip resurfacing: a minimum follow-up of ten years. J Bone Joint Surg [Br] 2011;93-B:27–33. 27. Kindsfater KA, Sychterz Terefenko CJ, Gruen TA, Sherman CM. Minimum 5- year results of modular metal-on-metal total hip arthroplasty. J Arthroplasty 2012;27:545–550.

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28. McMinn DJ, Daniel J, Ziaee H, Pradhan C. Indications and results of hip resur- facing. Int Orthop 2011;35:231–237. 29. D’Antonio JA, Capello WN, Manley MT, Naughton M, Sutton K. A titanium- encased alumina ceramic bearing for total hip arthroplasty: 3- to 5-year results. Clin Orthop Relat Res 2005;441:151–158. 30. Sarmiento A, Ebramzadeh E, Gogan WJ, McKellop HA. Total hip arthroplasty with cement: a long-term radiographic analysis in patients who are older than fifty and younger than fifty years. J Bone Joint Surg [Am] 1990;72-A:1470–1476. 31. Kobayashi S, Eftekhar NS, Terayama K, Joshi RP. Comparative study of total hip arthroplasty between younger and older patients. Clin Orthop Relat Res 1997;339:140–151. 32. Delaunay CP, Bonnomet F, Clavert P, Laffargue P, Migaud H. THA using metal- on-metal articulation in active patients younger than 50 years. Clin Orthop Relat Res 2008;466:340–346. 33. Boesenach B, van der Heide HJ, Nelissen RG. No improvement in long-term wear and revision rates with the second-generation Biomet cup (RingLoc) in young patients: 141 hips followed for median 12 years. Acta Orthop 2011;82:664–668. 6 34. Kim YH, Kim JS, Park JW, Joo JH. Comparison of total hip replacement with and without cement in patients younger than 50 years of age: the results at 18 years. J Bone Joint Surg [Br] 2011;93-B:449–455. 35. Hwang KT, Kim YH, Kim YS, Choi IY. Cementless total hip arthroplasty with a metal-on- metal bearing in patients younger than 50 years. J Arthroplasty 2011;26:1481–1487. 36. Schmitz MW, Busch VJ, Gardeniers JW, et al. Long-term resuls of cemented total hip arthroplasty in patients younger than 30 years and the outcome of subse- quent revisions. BMC Musculoskelet Disord 2013;14:37. 37. Busch VJ, Gardeniers JW, Verdonschot N, Slooff TJ, Schreurs BW. Acetabu- lar reconstruction with impaction bone-grafting and a cemented cup in patients younger than fifty years old: a concise follow-up, at twenty to twenty-eight years, of a previous report. J Bone Joint Surg [Am] 2011;93-A:367–371. 38. Jameson SS, Baker PN, Mason J, et al. The design of the acetabular component and size of the femoral head influence the risk of revision following 34 721 single- brand cemented hip replacements: a retrospective cohort study of medium-term data from a National Joint Registry. J Bone Joint Surg [Br] 2012;94-B:1611–1617.

124 CHAPTER 6

Clinical and radiological outcome of the cemented Contemporary acetabular component in patients < 50 years of age

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Systematic review: lack of evidence for the success of revision arthroplasty outcome in younger patients

Marloes W.J.L. Schmitz, Carla Timmer,

Gerjon Hannink, B. Willem Schreurs

Submitted to Hip International

CHAPTER 7 Cemented total hip arthroplasty and impaction bone grafting in young patients

ABSTRACT

Background and purpose: Total hip arthroplasties (THAs) in younger patients are becoming increasingly popular. However, the outcome of subsequent revisions in younger patients is not well known and, therefore, their success (subsequent revision prosthesis survival) might be overestimated. We investigated available data on the outcome of primary- and subsequent revision THAs performed in the same cohort of patients who underwent primary THA before the age of 50 years old.

Methods: Medline, Embase and the Cochrane Library (CENTRAL) were searched up until 13th April 2016 for studies that reported both the survival of primary- and subsequent revisions THA of single cohorts of patients younger than 50 years old. Eligible articles had to include Kaplan Meier analysis or competing risk analysis for survival of the primary THA at a mean follow-up of ten years, as well as for the subsequent revision THA within the same cohort.

Results: We found 4,799 unique records; 43 of which were potentially eligible. Only 7 one paper met our inclusion criteria. It reported on the survival of 69 primary prostheses at a mean of more than ten years follow-up and 13 subsequent revisions.

Conclusions: There is a clear lack of evidence about the outcomes of the revision arthroplasty in younger patients. Only one study reported the survival-rate of subsequent revision arthroplasty with the minimum ten-year survival rate of the original THA cohort. In the future, this serious lack of knowledge could result in a large number of patients with no further reconstructive options after failed THA, and a large medical burden for society.

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Systematic review: lack of evidence for the success of revision arthroplasty outcome in younger patients

BACKGROUND

Total hip arthroplasty (THA) is one of the most successful and cost-effective operations in medicine.1 Due to its success in reducing pain and restoring mobility to near normal in older patients,2-6 THA is increasingly used in younger patients who suffer from primary- and secondary osteoarthritis.2, 5, 6 Survival of a THA is often expressed as the duration to failure of one or both components of the total hip prosthesis for any reason, including aseptic loosening, septic loosening, trauma, recurrent dislocations, or any other reason. Literature shows comparable early results of THA in young patients compared to older patients, but within ten years after surgery, a decline of the survival of the prosthesis in younger patients aged under 50 has been seen.2, 5 This less successful survival, in combination with the fact that many young patients will outlive their primary total hip implant due to their longer life-expectancy, makes high numbers of revisions in these younger patients inevitable.7 It is imperative that these younger patients are informed about the chances of revision, and on the outcome of these revisions.8-11 However, there is a serious lack of knowledge on the outcome of subsequent revisions in young patients. And, as more and more younger patients undergo operations, this could result in large numbers of patients who will have no further reconstructive options after failed hip arthroplasty in the future, which would present a large medical burden to society. 7 Survival of primary THA in cohorts of younger patients has been widely published.2, 10, 12-22 Alongside this, there are reports on separate survival results of revision arthroplasties. However, most publications concerning revisions of THAs in younger patients include a number of revision cases performed over particular period of time. Results of these revisions are often published without detailed information on the characteristics of the patients and implants from the complete original or different primary cohorts, from which the revisions were reported. In these cases, it is unclear if the primary arthroplasty was easy to revise. And, therefore, the influence of the fixation of the primary implant and available bone stock after removal on the survival of the revision implant is unknown. This might result in selective outcome reporting for revision total hip arthroplasty which could lead to a worrisome situation; incomplete information on the success of total hip arthroplasty in younger patients; and inaccurate decision-making. When reporting on revision THA, the survival results and baseline characteristics of the complete primary THA cohort should be included to obtain accurate information

129 Cemented total hip arthroplasty and impaction bone grafting in young patients

on which revision THA could be successful for an individual patient. The results of the primary hip prosthesis, the revisability of hip arthroplasties and survival of its subsequent revision should be investigated and presented together. In summary, we can state that in cases of total hip arthroplasty, any re-intervention on a hip, either to the cup or the femoral component should be considered as important, because for the patient, the overall number of re-operations and the revisability of the prosthesis are the outcome parameters that count. Therefore, survival of a prosthesis should be presented as survival of the whole construct (both acetabular- and femoral components). Furthermore, the influence of the primary construct on the revision construct should be taken into account when judging survival of total hip arthroplasty in younger patients. To the best of our knowledge, no systematic reviews are available on this topic. Therefore, we performed a systematic review of current literature regarding the available results of subsequent revision arthroplasties in cohorts of patients, who received their primary THA aged under 50 years old at the time of surgery, with a mean follow-up of ten years after primary hip arthroplasty.

PATIENTS AND METHODS 7 A systematic review of studies that evaluated the survival data of both primary- and revision hip arthroplasties in the same cohorts of patients who received their primary total hip implant under the age of 50 years old was performed. The review protocol and methodology were prospectively registered in PROSPERO (registration number CRD42016039602). The review was performed according to the PRISMA guidelines.

Eligibility criteria To answer the research question and search for appropriate available literature that combined the results of primary- and revision total hip arthroplasties in younger patients, we used the following eligibility criteria: 1. studies that evaluated the survival data of both primary- and revision hip arthroplasties in the same cohorts of patients who received their primary total hip implant under the age of 50 years old;

130 CHAPTER 7

Systematic review: lack of evidence for the success of revision arthroplasty outcome in younger patients

2. with a mean follow-up of ten years after primary total hip arthroplasty; and 3. that included both acetabular- and femoral components.

Review articles and case reports were excluded. Studies that presented data on hemi- arthroplasties and resurfacing arthroplasties were also excluded. Only total hip arthroplasty procedures were included. Our primary outcome was the survival of revision arthroplasties in cohorts of patients, from whom, the survival of all primary hip arthroplasties was also described. Survival was defined as the survival of the primary (or revision) arthroplasty, with endpoint as (re-) revision for aseptic loosening and/or any reason (including (re-)revision for aseptic loosening, septic loosening, luxation and other causes mentioned for (re-) revision of one of the total hip components). Only articles written in English, Dutch, German or French were considered eligible.

Search strategy Medline (PubMed), Embase and the Cochrane Library (CENTRAL) were searched (the last search was performed 13th April 2016) for articles that reported both the survival of primary prosthesis in cohorts of patients younger than 50 years old, as well as the survival of the subsequent revision THAs in the same cohort. Our search strategy was 7 developed together with a medical information specialist from the Medical Library of Radboud university medical center in Nijmegen, the Netherlands. Keywords used to develop the search were ‘hip prosthesis’, ‘revision’, ‘young’ and ‘cohort’. The detailed search strategy is provided in Appendix 1. The Cochrane Library showed evidently fewer results compared to Medline and Embase, and, therefore, we omitted the search terms related to ‘cohort’ and ‘young’ to reveal as many possible eligible articles within the Cochrane Library database. Language limits were set to English, Dutch, German and French. The complete reference lists of the possible eligible papers were screened for potentially missed papers.

Selection of studies After removal of duplicates, articles were screened on title and abstract by two independent reviewers (MS and CT). Any discrepancies were resolved by discussion. Full text copies of eligible articles were assessed and included when they met our inclusion criteria.

131 Cemented total hip arthroplasty and impaction bone grafting in young patients

Data collection process and items Survival data of primary THA, as well as the survival of the revision THA within the same cohort, including estimated Kaplan-Meier survival or competing risk survival analysis, were extracted. In addition, the survival for aseptic loosening and/or any reason of both acetabular- and femoral components of the primary cohort were also extracted. Baseline characteristics including age, gender and body mass index (BMI) were collected, as well as fixation method (cemented, uncemented and hybrid) and indication at time of primary surgery. All of this was carried out by two independent reviewers (MS and CT).

Risk of bias assessment Bias risk was assessed at study level and the quality of the included cohort studies was scored by two authors (CT, GH) using the Newcastle-Ottawa Scale (NOS) for assessment of the quality of non-randomised studies in meta-analysis23. A study could be awarded a maximum of one star for each of the four numbered items within the ‘Selection’ and ‘Outcome’ categories. A maximum of two stars could be given for ‘Comparability’. In total, a maximum of eight stars could be received. We used the Newcastle-Ottawa scale, as it is one of the two most useful tools of the many instruments created to assess methodological quality of non-randomised studies of interventions, and reviewed 7 systematically by Deeks et al.24, as described in the Cochrane Handbook for Systematic Reviews of Interventions25.

Subgroup analysis If three or more comparable studies were available, subgroup analyses for fixation technique of the prosthesis (cemented, uncemented and hybrid) and for diagnosis at time of primary surgery were performed.

RESULTS

Search and summary of results Our search strategy resulted in 4,799 unique records (Figure 1). The subsequent selection procedure resulted in 43 potentially eligible articles, of which one met the inclusion criteria and could be included. This paper describes one of our own studies that includes

132 CHAPTER 7

Systematic review: lack of evidence for the success of revision arthroplasty outcome in younger patients patients younger than 30 years old, and reported on 13 revisions from a primary cohort of 69 primary THAs21. Index surgery was performed between 1988 and 2004, and analysis was carried out in 2011. Diagnosis at time of primary surgery was described for all cases. Mean age was 25 years (16-29) at primary implantation. Survival of the primary prostheses with aseptic loosening as reason for revision was 90% (CI 79-96) after ten years. All primary- and revision cases involved cemented implants. Mean follow-up of the primary cohort was 11.5 years (7-23). There were 13 revisions in this cohort. The diagnoses of these 13 hips at primary surgery were not clearly described. Three THAs were revised for septic loosening and ten acetabular components were revised; due to aseptic loosening, none of the stems were revised separately. Only one revision required a re-revision after 13 years, the reason for revision was not reported. Survival of the revision THAs was, therefore, 100% after ten years.

Records identified through database searching: Medline: 3.938 Records identified through other Embase: 3.184 sources: 291 Cochrane: 304 Total: 7.426

Records excluded Records after duplicates (n = 4.756) removed 7 (n = 4.799) By title (n = 3.210) • No survival primary and revision (n = 2.023) • No cup and stem data (n = 1.142) • Review or case report (n = 45)

By abstract (n=1.546) Records screened • No survival primary and revision (n = 1.477) (n = 4.799) • No cup and stem data (n = 37) • Follow-up <10 years (n = 30) • Review or case report (n = 2)

Full text articles assessed Full-text articles excluded for eligibility (n = 42) (n = 43) • No survival primary and revision (n = 42)

Studies available for review (n = 1)

FIGURE 1. Flow chart depicting the results of identifying eligible articles for review

133 Cemented total hip arthroplasty and impaction bone grafting in young patients

Quality assessment According to the Newcastle-Ottawa Scale (NOS), three out of four stars were awarded for ‘selection’. ‘Comparability’ was not applicable, as no comparison of cohorts was performed. Regarding ‘outcome’, three out of three stars were awarded.

Subgroup analysis Subgroup analysis was not performed, as only one study could be included.

DISCUSSION

Comparison to literature We identified only one study reporting on revisions, whilst reporting on the survival of the primary THA cohort in patients under 50 years old. This is a striking result, as we know from studies including patients of all ages that it is important to be familiar with the effect of the primary implant and the fixation technique used on the results of revision. For example, Lie et al26 reported on 78,534 primary operations that included people of all ages with a median follow-up of 5.6 years, and found the probability of 7 requiring revision surgery within ten years for all primary operations to be 11.4% (95% CI: 11.3-11.4). Whereas for the subsequent revisions, with no infection, the ten-year risk of failure was 25.6% (95% CI: 24.8-26.4), which emphasises the higher failure risk of revisions compared to primary prosthesis. Both acetabular- and femoral components showed different survival rates per revision technique, which stresses the importance of obtaining more knowledge on the influence of the primary implant and its fixation technique in success of the final revision. Although total hip arthroplasty for younger patients has been acclaimed as a reliable solution, one might say that this is still based on incomplete data that lacks subsequent revision outcomes. Remarkably, there is a growing body of literature that has reported on cohorts of total hip arthroplasties in younger patients with primary outcomes,2, 12, 14, 15, 17, 27- 31 even including follow-up of more than 25 years.16, 18, 19 Overall, there are also a few studies that report on revision total hip arthroplasty in younger patients. Such studies are of clinical importance and do meet some of our inclusion criteria, however, none report data on revision arthroplasty in combination with results of the primary THA

134 CHAPTER 7

Systematic review: lack of evidence for the success of revision arthroplasty outcome in younger patients cohort.8, 9,11,32-36 Often, the authors solely present a subgroup of their cohort and the primary survival data are omitted. The characteristics of the original primary THA, including the type of component, fixation technique and baseline characteristics of patients are omitted. Furthermore, information on the survival of the primary component that was revised is not complete. For example, it is important to know if the primary component already failed before it even reached a follow-up of ten years, or, in cases of an acetabular component revision, it is useful to know if the femoral component was also exchanged in the meantime. So, the literature on revisions in younger patients appears to be selectively reported. This selective reporting of revision total hip arthroplasty outcome is alarming, as we cannot determine which of the revised patients had a durable primary implant and what patient characteristics and fixation techniques might have contributed to the reported survival results. Survival data of THA in younger patients have also been published in National Joint Registries,2, 5, 37 and can be helpful to indicate trends or record differences in outcomes with otherwise extremely low incidence.37-40 However, these registers also often do not reveal complete information about the initial diagnosis, survival of the primary implant or the radiographical images at time of revision.41

Possible explanations 7 One possible explanation of the lack of information available could be the use of the resurfacing prosthesis. After its re-introduction in the 1990s, the resurfacing prosthesis became quite popular, especially for use in the younger patient, and this could have impacted the number of cohorts of younger patients receiving THA. An additional explanation for our findings could be that collecting data such as primary- and subsequent revision arthroplasty outcomes requires strict and intensive follow-up of young patients, as also suggested by others.8-11 As revisions are often performed in specialised referral centres, practice can lead to mixed cohorts, or a number of patients lost to follow-up. On the other hand, primary cohorts of patients that have been described already years ago in literature should be described again somewhere in time to present their revision outcome as well. Even though these results might show varying success rates or include old techniques, the information can help in defining the best treatment options for younger patients suffering from osteoarthritis, especially when radiographic follow-up is complete. It should be emphasised that THA in young patients is often a continuous

135 Cemented total hip arthroplasty and impaction bone grafting in young patients

process of multiple surgeries, and that we currently miss essential ‘pieces of the puzzle’ in the literature.

Limitations There are some limitations to our study that should be discussed. Firstly, as we included studies that reported on patients of 50 years old and younger at the time of primary surgery, we might have excluded studies that have reported on patients aged <65 years or older and might include subgroups of younger age. Secondly, by including only cohorts that present at least a mean follow-up of ten years of their primary prosthesis, we might have excluded some useful articles that presented revision data. Furthermore, one must realise that revision rates capture not all the implants that clinically fail but have not been treated surgically. We consider that with the currently available results of hip arthroplasty, presenting results at shorter follow-up would not yield any representative and useful results for clinical practice. Thirdly, by including articles reporting on both components, we might have excluded those reporting on only acetabular - or femoral components. The reason for this is that the results of only one component are of lower clinical relevance to patients in discussing survival. Lastly, we have appraised the quality of our own study. We have performed this as accurately and completely as possible. 7 CONCLUSION

There is this little information available on the revisability of hip prosthesis in young patients. We should be aware of selective outcome reporting in younger patients in treating those patients with end-stage osteoarthritis, as we cannot currently adequately inform younger patients on their future survival expectations regarding different total hip arthroplasty techniques. This could potentially lead to large numbers of patients with hips that cannot be reconstructed and can generate high medical costs for societies.

136 CHAPTER 7

Systematic review: lack of evidence for the success of revision arthroplasty outcome in younger patients

REFERENCES

4. Learmonth ID, Young C, Rorabeck C: The operation of the century: total hip replacement. Lancet 2007, 370(9597):1508-1519. 5. Busch V, Klarenbeek R, Slooff T, Schreurs BW, Gardeniers J: Cemented hip designs are a reasonable option in young patients. Clinical orthopaedics and related research 2010, 468(12):3214-3220. 6. Kim M, Kadowaki T: High long-term survival of bulk femoral head autograft for acetabular reconstruction in cementless THA for developmental hip dysplasia. Clinical orthopaedics and related research 2010, 468(6):1611-1620. 7. Haddad FS, Rayan F: The role of impaction grafting: the when and how. Orthopedics 2009, 32(9). 8. Yan MN, Dai KR, Tang TT, Zhu ZA, Lou JR: Reconstruction of peri-implant bone defects using impacted bone allograft and BMP-2 gene-modified bone marrow stromal cells. Journal of biomedical materials research Part A 2010, 93(1):304-313. 9. Liu XZ, Yang SH, Xu WH, Liu GH, Yang C, Li J, Ye ZW, Liu Y, Zhang YK: Clinical observation of particulate cancellous bone impaction grafting in combination with total hip arthroplasty for acetabular reconstruction. Chinese journal of traumatology = Zhonghua chuang shang za zhi / Chinese Medical Association 2008, 11(5):301-305. 7 10. Kurtz SM, Lau E, Ong K, Zhao K, Kelly M, Bozic KJ: Future young patient demand for primary and revision joint replacement: national projections from 2010 to 2030. Clinical orthopaedics and related research 2009, 467(10):2606-2612. 11. Comba F, Buttaro M, Pusso R, Piccaluga F: Acetabular revision surgery with impacted bone allografts and cemented cups in patients younger than 55 years. International orthopaedics 2009, 33(3):611-616. 12. Raut VV, Siney PD, Wroblewski BM: Revision of the acetabular component of a total hip arthroplasty with cement in young patients without rheumatoid arthritis. J Bone Joint Surg Am 1996, 78(12):1853-1856. 13. Streit MR, Weiss S, Andreas F, Bruckner T, Walker T, Kretzer JP, Ewerbeck V, Merle C: 10- year results of the uncemented Allofit press-fit cup in young patients.Acta orthopaedica 2014, 85(4):368-374. 14. Te Stroet MA, Rijnen WH, Gardeniers JW, van Kampen A, Schreurs BW: Satisfying Outcomes Scores and Survivorship Achieved With Impaction Grafting for Revision THA in Young Patients. Clinical orthopaedics and related research 2015, 473(12):3867-3875.

137 Cemented total hip arthroplasty and impaction bone grafting in young patients

15. de Kam DC, Gardeniers JW, Veth RP, Schreurs BW: Good results with cemented total hip arthroplasty in patients between 40 and 50 years of age. Acta orthopaedica 2010, 81(2):165- 170. 16. Greiner JJ, Callaghan JJ, Bedard NA, Liu SS, Gao Y, Goetz DD: Fixation and Wear With Contemporary Acetabular Components and Cross-Linked Polyethylene at 10-Years in Patients Aged 50 and Under. The Journal of arthroplasty 2015, 30(9):1577-1585. 17. Hwang KT, Kim YH, Kim YS, Choi IY: Cementless total hip arthroplasty with a metal-on- metal bearing in patients younger than 50 years. The Journal of arthroplasty 2011, 26(8):1481- 1487. 18. Innmann MM, Gotterbarm T, Kretzer JP, Merle C, Ewerbeck V, Weiss S, Aldinger PR, Streit MR: Minimum ten-year results of a 28-mm metal-on-metal bearing in cementless total hip arthroplasty in patients fifty years of age and younger. International orthopaedics 2014, 38(5):929-934. 19. Keener JD, Callaghan JJ, Goetz DD, Pederson DR, Sullivan PM, Johnston RC: Twenty-five- year results after Charnley total hip arthroplasty in patients less than fifty years old: a concise follow-up of a previous report. J Bone Joint Surg Am 2003, 85-A(6):1066-1072. 20. Kim SM, Lim SJ, Moon YW, Kim YT, Ko KR, Park YS: Cementless modular total hip arthroplasty in patients younger than fifty with femoral head osteonecrosis: minimum fifteen- 7 year follow-up. The Journal of arthroplasty 2013, 28(3):504-509. 21. Kim YH, Kim JS, Park JW, Joo JH: Comparison of total hip replacement with and without cement in patients younger than 50 years of age: the results at 18 years. The Journal of bone and joint surgery British volume 2011, 93(4):449-455. 22. Kim YH, Park JW, Park JS: The 27 to 29-year outcomes of the PCA total hip arthroplasty in patients younger than 50 years old. The Journal of arthroplasty 2014, 29(12):2256-2261. 23. Lampropoulou-Adamidou K, Georgiades G, Vlamis J, Hartofilakidis G: Charnley low-friction arthroplasty in patients 35 years of age or younger. Results at a minimum of 23 years. The bone & joint journal 2013, 95-B(8):1052-1056. 24. Schmitz MW, Busch VJ, Gardeniers JW, Hendriks JC, Veth RP, Schreurs BW: Long-term results of cemented total hip arthroplasty in patients younger than 30 years and the outcome of subsequent revisions. BMC musculoskeletal disorders 2013, 14:37. 25. Takenaga RK, Callaghan JJ, Bedard NA, Liu SS, Klaassen AL, Pedersen DR: Cementless total hip arthroplasty in patients fifty years of age or younger: a minimum ten-year follow-up. J Bone Joint Surg Am 2012, 94(23):2153-2159.

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26. http://www.ohri.ca/programs/clinical_epidemiology/oxford.asp 27. Deeks JJ, Dinnes J, D’Amico R, Sowden AJ, Sakarovitch C, Song F, Petticrew M, Altman DG, International Stroke Trial Collaborative G, European Carotid Surgery Trial Collaborative G: Evaluating non-randomised intervention studies. Health technology assessment 2003, 7(27):iii-x, 1-173. 28. Higgins JPT GSe: Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. Available from http://handbook. cochrane.org]. 2011. 29. Lie SA, Havelin LI, Furnes ON, Engesaeter LB, Vollset SE: Failure rates for 4762 revision total hip arthroplasties in the Norwegian Arthroplasty Register. The Journal of bone and joint surgery British volume 2004, 86(4):504-509. 30. Roidis NT, Pollalis AP, Hartofilakidis GC: Total hip arthroplasty in young females with congenital dislocation of the hip, radically improves their long-term quality of life. The Journal of arthroplasty 2013, 28(7):1206-1211. 31. Chana R, Facek M, Tilley S, Walter WK, Zicat B, Walter WL: Ceramic-on-ceramic bearings in young patients: outcomes and activity levels at minimum ten-year follow-up. The bone & joint journal 2013, 95-B(12):1603-1609. 32. Kearns SR, Jamal B, Rorabeck CH, Bourne RB: Factors affecting survival of uncemented total hip arthroplasty in patients 50 years or younger. Clinical orthopaedics and related research 7 2006, 453:103-109. 33. Abdel MP, Stryker LS, Trousdale RT, Berry DJ, Cabanela ME: Uncemented acetabular components with femoral head autograft for acetabular reconstruction in developmental dysplasia of the hip: a concise follow-up report at a mean of twenty years. J Bone Joint Surg Am 2014, 96(22):1878-1882. 34. Pakos EE, Paschos NK, Xenakis TA: Long Term Outcomes of Total Hip Arthroplasty in Young Patients under 30. Archives of bone and joint surgery 2014, 2(3):157-162. 35. Adelani MA, Crook K, Barrack RL, Maloney WJ, Clohisy JC: What is the prognosis of revision total hip arthroplasty in patients 55 years and younger? Clinical orthopaedics and related research 2014, 472(5):1518-1525. 36. Lee PT, Lakstein DL, Lozano B, Safir O, Backstein J, Gross AE: Mid-to long-term results of revision total hip replacement in patients aged 50 years or younger. The bone & joint journal 2014, 96-B(8):1047-1051.

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37. Girard J, Glorion C, Bonnomet F, Fron D, Migaud H: Risk factors for revision of hip arthroplasties in patients younger than 30 years. Clinical orthopaedics and related research 2011, 469(4):1141-1147. 38. Stromberg CN, Herberts P: Cemented revision total hip arthroplasties in patients younger than 55 years old. A multicenter evaluation of second-generation cementing technique. The Journal of arthroplasty 1996, 11(5):489-499. 39. Busch VJ, Gardeniers JW, Verdonschot N, Slooff TJ, Schreurs BW: Acetabular reconstruction with impaction bone-grafting and a cemented cup in patients younger than fifty years old: a concise follow-up, at twenty to twenty-eight years, of a previous report. J Bone Joint Surg Am 2011, 93(4):367-371. 40. Sedrakyan A, Romero L, Graves S, Davidson D, de Steiger R, Lewis P, Solomon M, Vial R, Lorimer M: Survivorship of hip and knee implants in pediatric and young adult populations: analysis of registry and published data. J Bone Joint Surg Am 2014, 96 Suppl 1:73-78. 41. Dreyer NA, Garner S: Registries for robust evidence. Jama 2009, 302(7):790-791. 42. Graves SE: The value of arthroplasty registry data. Acta orthopaedica 2010, 81(1):8-9. 43. Hailer NP, Garellick G, Karrholm J: Uncemented and cemented primary total hip arthroplasty in the Swedish Hip Arthroplasty Register. Acta orthopaedica 2010, 81(1):34-41. 44. Pivec R, Johnson AJ, Mears SC, Mont MA: Hip arthroplasty. Lancet 2012, 380(9855):1768- 7 1777.

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APPENDIX 1:

Detailed search strategy Medline

1) “Hip Prosthesis”[Mesh] OR “Arthroplasty, Replacement, Hip”[Mesh] OR Hip Replacement Arthroplasty[tiab] OR Hip Replacement Arthroplasties[tiab] OR Hip Prosthesis Implantation[tiab] OR Hip Prosthesis Implantations[tiab] OR Total Hip Replacements[tiab] OR Total Hip Replacement[tiab] OR Hip Prostheses[tiab] OR Hip Prosthesis[tiab] OR (“arthroplasty”[tiab] AND “replacement”[tiab] AND “hip”[tiab]) OR (“total”[tiab] AND “hip”[tiab] AND “arthroplasty”[tiab]) OR total hip[tiab] 2) Revision OR Revisions 3) Adolescents[tiab] OR Adolescent[tiab] OR Teens[tiab] OR Teen[tiab] OR Teenagers[tiab] OR Teenager[tiab] OR Youth[tiab] OR Youths[tiab] OR Young[tiab] OR Adolescence[tiab] OR Adult[tiab] OR Adults[tiab] OR Middle-age[tiab] OR Middle-aged[tiab] OR Child[tiab] OR Children[tiab] OR “Adolescent”[Mesh] OR “Adult”[Mesh:noexp] OR “Middle Aged”[Mesh] OR “Young Adult”[Mesh] OR “Child”[Mesh] 4) Cohort OR Concurrent Studies OR Concurrent Study OR Incidence Studies OR 7 Incidence Study OR Follow-Up OR Follow up OR Longitudinal OR Prospective OR Retrospective OR “Cohort Studies”[Mesh]

Detailed search strategy Embase

1) exp hip prosthesis/ OR exp hip arthroplasty/ OR Hip Replacement Arthroplasty. ti,ab. OR Hip Replacement Arthroplasties.ti,ab. OR Hip Prosthesis Implantation. ti,ab. OR Hip Prosthesis Implantations.ti,ab. OR Total Hip Replacements.ti,ab. OR Total Hip Replacement.ti,ab. OR Hip Prostheses.ti,ab. OR Hip Prosthesis.ti,ab. OR (“arthroplasty”.ti,ab. AND “replacement”.ti,ab. AND “hip”).ti,ab. OR (“total” AND “hip” AND “arthroplasty”) ti,ab OR total hip.ti,ab.) 2) (Revision or Revisions).mp. 3) (Adolescents OR AdolescentOR Teens OR Teen. OR Teenagers OR Teenager OR Youth OR Youths OR Young OR Adolescence OR Adult OR Adults.ti,ab. OR

141 Cemented total hip arthroplasty and impaction bone grafting in young patients

Middle-age.ti,ab. OR Middle-aged.ti,ab. OR Child.ti,ab. OR Children).ti,ab. OR exp adolescent/ or adult/ or exp child/ or middle aged/) 4) (Cohort or Concurrent Studies or Concurrent Study or Incidence Studies or Incidence Study or Follow-Up or Follow up or Longitudinal or Prospective or Retrospective). mp. OR cohort analysis/)

Detailed search strategy Cochrane

#1 MeSH descriptor: [Hip Prosthesis] explode all trees #2 MeSH descriptor: [Arthroplasty, Replacement, Hip] explode all trees #3 Hip Replacement Arthroplasty or Hip Replacement Arthroplasties or Hip Prosthesis Implantation or Hip Prosthesis Implantations or Total Hip Replacements or Total Hip Replacement or Hip Prostheses or Hip Prosthesis or (“arthroplasty” and “replacement” and “hip”) or (“total” and “hip” and “arthroplasty”) or total hip:ti,ab,kw (Word variations have been searched) #4 #1 or #2 or #3 #5 revision or revisions:ti,ab,kw (Word variations have been searched) #6 #4 and #5 7

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7

143

A new approach to improve cemented cup survival in primary total hip arthroplasty in young patients: acetabular impaction bone grafting A preliminary report with a minimum follow-up of two years

Marloes W.J.L Schmitz, Ena Colo, Wim H.C. Rijnen,

Jean W.M. Gardeniers, B. Willem Schreurs

CHAPTER 8 Cemented total hip arthroplasty and impaction bone grafting in young patients

ABSTRACT

The cup survival in patients under 50 years is the weakest link in total hip arthroplasty (THA), both in cemented and uncemented prostheses. We hypothesized that the application of acetabular impaction bone grafting (IBG) in primary cemented THAs will improve the bone cement interdigitation in these patients and will improve the cup survival, even in the absence of acetabular bone stock loss. However, the application of an additional layer of impacted bone grafts in non deficient acetabula might introduce an additional failure mechanism. Therefore, we compared the early revision rates and complications between two cohorts of patients: hips without an acetabular defect, that received a straightforward cemented cup (non-IBG group, n= 30) and hips that received a cemented cup after a layer of impacted bone grafts (IBG group, n=29). Mean age at index surgery was 36.2 (15.3-49.4) years. The minimal follow-up was 2 years. Radiological and clinical parameters were assessed. Kaplan-Meier survival analyses were used to determine the survivorship of the acetabular component. There were no specific per- or postoperative complications for the IBG procedure, although the additional surgical time was 8 minutes. Survival for endpoint revision for any reason for the non-IBG group and IBG group was 96.7% (95% CI: 78.6-99.5) and 93.1% (95% CI: 75.1-98.2) at two 8 years, respectively, due to three revisions for recurrent dislocations and one septic loosening. The two-year acetabular survivorship with endpoint revision for aseptic loosening was 100% in both the non-IBG and IBG group. There was one radiological failure in the non-IBG group, and none in the IBG group. Acetabular IBG during primary cemented THA in young patients without an acetabular defect might be an attractive technique to improve the cup survival in this demanding group. Based on already available long-term reports of the survival of cemented cup after IBG in bone deficient cases, mechanical failure after a stable initial situation is uncommon and full incorporation after 2 years can be expected.

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A new approach to improve cemented cup survival in primary total hip arthroplasty in young patients: acetabular impaction bone grafting

INTRODUCTION

Total hip arthroplasties (THA) in patients less than 50 years of age remain a challenge in orthopedic surgery. Initially, predominantly cemented implants were used, but the outcomes of these cemented cups at longer follow-up appeared inferior in young patients compared to older patients. Over the past years mainly uncemented primary THA designs have been used and although the designs have improved in the course of years, the outcomes of uncemented cups in young patients is also still not satisfying1. On the long term, the weakest link of a THA in these young patients remains the acetabular side for both cemented and uncemented techniques.2-12 Since 1979 we have been using acetabular impaction bone grafting (IBG) in complex primary THA and revision THA to reconstruct acetabular bone loss.13 We previously evaluated the outcome of this technique in patients under 50 years and realized that, even at a long follow-up, the results were very acceptable, certainly when the complexity of these cases is taken into account.14 The often very sclerotic subchondral bone plate in young patients at the primary THA makes it is more difficult to create an optimal cement-bone interdigitation, especially in absence of acetabular bone defects. Based on this observation, we implemented a new surgical protocol in this patient group. From 2008, acetabular IBG in primary THA is applied in all patients under 50 years old, whether an acetabular defect is present or not. Our hypothesis is that the application of IBG in cases without acetabular defects will improve the bone-cement interdigitation and subsequently benefit the fixation of the cemented cup on the long-term. 8 In this preliminary report, we present the short-term outcomes at a minimum of two years follow-up in patients under 50 years without an acetabular bone stock defect, who received a primary cemented THA with acetabular IBG and compared this group to a similar cohort in which the cups were directly cemented without IBG. The aim is to focus on the intra- and early postoperative complications related to the IBG-technique when using this new approach.

147 Cemented total hip arthroplasty and impaction bone grafting in young patients

METHODS

Study group All consecutive young patients (< 50 years) that received a primary cemented THA from 1-1-2006 up to 1-1-2010 in our institution and had no pre-existing acetabular bone defect based on pre-operative radiographs and intraoperative findings, were included. Patients who had a THA for oncologic indications were excluded. From 1-1-2006 up to 2008, we included all patients who received a directly cemented total hip without acetabular IBG (non-IBG group). Per 1-1-2008 we implemented our protocol and performed acetabular IBG in all patients under 50 years. Thus, those young patients that received a THA from 1-1-2008 up to 2010, without an acetabular defect and with IBG, were included (IBG group). The total population consisted of 59 hips in 53 patients; 30 (51%) hips in the non-IBG group and 29 (49%) hips in the IBG group. Patient characteristics per group are listed in table I. The primary diagnoses per group are listed in table II.

TABLE I. Patient characteristics Total group non-IBG IBG p-value

Gender, n (%) 0.12

Male 29 (49) 18 (62) 11 (38)

Female 30 (51) 12 (40) 18 (62) 8 Age, mean (range) 36.5 (15.3-49.4) 38.1 (18.0-49.4) 34.9 (15.3-48.1) 0.33 THA side, n (%) 0.61

Left 29 (49) 16 (55) 13 (45)

Right 30 (51) 14 (47) 16 (53)

Bilateral, n (%)* 10 (19) 6 (60) 4 (40)

Follow-up, mean (range)** 3.5 (0.2-6.2) 4.9 (0.2-6.2) 2.8 (0.5-4.1) <0.01 * Number of patients who received a contralateral THA during the inclusion period of the study ** Until revision of any component P-values for differences between IBG and non-IBG were calculated using the Fisher exact test in case of 2*2 tables and the Mann-Whitney test in case of continuous outcome.

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A new approach to improve cemented cup survival in primary total hip arthroplasty in young patients: acetabular impaction bone grafting

TABLE II. Indications for primary total hip arthroplasty Indication Total group, n (%) non-IBG (n) IBG (n)

Corticosteroid induced AVN 18 (30.5) 14 4

Posttraumatic osteoarthritis 9 (15.3) 4 5

AVN of unknown origin 8 (13.6) 5 3

Primary osteoarthritis 5 (8.5) 1 4

SCA due to Perthes’ disease 4 (6.8) 0 4

SCA due to CHD 3 (5.1) 1 2

SCA due to rheumatoid arthritis 3 (5.1) 2 1

SCA due to protrusio acetabuli 2 (3.4) 0 2

Epiphysiolysis 2 (3.4) 0 2

SCA due to Bechterew’s disease 1 (1.7) 0 1

SCA due to posttraumatic AVN 1 (1.7) 1 0

SCA due to osteonecrosis in sicklecell anaemia 1 (1.7) 1 0

Coxitis 1 (1.7) 0 1

Other 1 (1.7) 1 0

Total 59 (100) 30 29

SCA = secondary coxarthritis, AVN = avascular necrosis, CHD = congenital hip dysplasia

Surgical technique All surgeries were performed by three orthopedic surgeons and a posterolateral approach was used in all cases. All patients received two grams intravenous cefazolin pre-operatively. 8 To optimize direct cementation (non-IBG group) or to stimulate vascularisation of the graft (IBG group), the acetabular bone bed was prepared with multiple two-millimeter drill-holes. Next the acetabulum was washed and dried and the cups of the non-IBG group were directly cemented onto this surface. In the IBG group, the patient’s femoral head was morsellised with a rongeur to provide cancellous bone chips with a diameter of 0.7-1.0 centimeters. However, as the femoral head was affected and sclerotic in some cases, a femoral head allograft from the bone bank was obtained. Autografts only were used in 21 (72.4%) hips, a combination of autografts and allografts was used in 5 (17.2 %) hips and allografts only in 3 (10.4%) hips. The bone chips were impacted with metal impactors and a mallet. The last metal impactor was at least two millimeters larger than the cup in order to facilitate a sufficient cement mantle. Vacuum-mixed cement loaded

149 Cemented total hip arthroplasty and impaction bone grafting in young patients

with antibiotics (Surgical Simplex®, Stryker Howmedica, Newbury, UK) was pressurized directly into the host bone (non-IBG group) or the impacted grafts (IBG group).15-18 Next, the polyethylene cup was inserted followed by a cemented femoral component (fig 1). The acetabular components used in both groups are displayed in table III. For the femoral component, an Exeter® stem (Stryker Howmedica, Newbury, UK) was used in all cases.

FIGURE 1. 8 Acetabular impaction bone grafting in hips without acetabular bonedefect. Impaction bone grafting technique: a) no acetabular bone defects are seen and no mesh is used. b) The femoral head was morselized with a rongeur to provide cancellous bone chips with a diameter of 0.7-1.0 centimeters. In case the femoral head was affected and sclerotic, a femoral head allograft from the bone bank was obtained. c) With a hammer and metal impacter, the bone chips are compressed tightly. d) Bone cement is introduced in a relatively viscous state and is pressurized to force bone cement into the graft before placement of the cup.

TABLE III. Types of acetabular component Type of acetabular implant Total group, n (%) non-IBG (n) IBG (n)

Exeter/ContemporaryTM* 53 (90) 24 29

Müller®/Allopro® cup# 6 (10) 6 0

*Stryker Howmedica, Newburry, UK, # Zimmer, Winterthur, Switzerland

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A new approach to improve cemented cup survival in primary total hip arthroplasty in young patients: acetabular impaction bone grafting

Postoperative treatment Thrombosis prophylaxis with low-molecular-weight heparin (LMWH) was given during six weeks postoperatively in both groups. Patients were mobilized according to a standardized protocol under the supervision of a physiotherapist: immediate full weight bearing with crutches for six weeks was allowed in the non-IBG group, whereas patients in the IBG group were allowed 10% of partial weight bearing during the first six weeks, followed by another six weeks of 50% weight bearing.

Clinical and radiographic analysis Clinical failure of the cup was defined as revision for any reason. For the radiographic analysis, anteroposterior radiographs of the pelvis and lateral radiographs of the hip were used. Radiographic evaluation was performed by three of the authors (MWJLS, EC, BWS) and classified on a consensus base. The following parameters were scored: cup position, graft incorporation,19 migration of either component, and radiolucent lines more than two millimeters wide in one of the three zones of DeLee and Charnley.20 Radiographic failure was defined as presence of radiolucent lines in three zones of DeLee and Charnley or migration of five millimeters or more in any direction.

Statistical analysis Kaplan-Meier survival analyses were used to determine the survivorship of the primary hip implant for the endpoints revision of the cup for 1) any reason, 2) aseptic loosening 3) septic loosening and 4) radiographic failure. P-values for differences in patient 8 characteristics between the non-IBG and IBG group were calculated using the Fisher exact test and the Mann-Whitney U test. The Log-rank test was used to determine any statistical differences between the survival of the non-IBG and IBG group. Statistical analysis was performed using statistical software package (SAS version 9.2, SAS Institute Inc, Cary, NC, USA).

151 Cemented total hip arthroplasty and impaction bone grafting in young patients

RESULTS

The two study groups showed no statistical difference in patient characteristics (table I). At the time of review, one patient (non-IBG group) was lost to follow-up after 0.47 years due to emigration and could not be contacted. None of the patients died, and every other non-revised patient had a minimum follow-up of two years. No intraoperative complications related to the placement of the cups occurred. The mean operation time was 105 minutes in the non-IBG group and 113 minutes in the IBG group. There was no difference in revision rate between the two methods due to a failure mechanism. During follow-up one reconstruction (IBG group) was revised for an early postoperative septic failure after 0.5 years, resulting in an infection rate of 1.7% in the whole cohort. There were no technique-related failures in both groups. However, three acetabular components were revised due to recurrent dislocations (one in the non-IBG group and two in the IBG group). All three patients had early osteoarthritis after a pelvic trauma: one patient suffered from a Pipkin fracture and two patients had an acetabular fracture. All three underwent previous surgeries after their initial trauma. At revision surgery, the acetabular component was stable in all three hips. In one hip the dislocation problem was solved by converting the original 28 mm cup into a 32 mm design. In the other two cases an Avantage cup was inserted. No further dislocations occurred in these cases. No reoperations other than the revision surgeries were performed. 8 The two-year survivorship rates of the cups of both groups are presented in table IV. For endpoint revision for any reason, the two-year estimated Kaplan-Meier survival of the non-IBG group was 96.7% (95% CI: 78.6-99.5), whereas this was 93.1% (95% CI: 75.1-98.2) for the IBG group. This difference was not statistically significant (log-rank, p = 0.157). The survival regarding the endpoint revision for aseptic loosening of any component was 100% in both the non-IBG and IBG group.

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A new approach to improve cemented cup survival in primary total hip arthroplasty in young patients: acetabular impaction bone grafting

TABLE IV. The percentage revision free survival after two years and 95% confidence intervals (CI) for the endpoints revision for 1) any reason, 2) aseptic loosening and 3) septic loosening. Percentage revision free for All cups (n=59) non-IBG (n=30) IBG (n=29)

Any reason 94.9 (84.9-98.3), n=54 96.7 (78.6-99.5), n=28 93.1 (75.1-98.2), n=26

Aseptic loosening 100 (94.6-100), n=54 100 (89.9-100), n=28 100 (89.1-100), n=26

Septic loosening 98.2 (88.2-99.8), n=54 100 (89.9-100), n=28 96.6 (77.9-99.5), n=26

Radiographic results Follow-up radiographs were complete for all patients (59 THAs). Of the 55 non-revised cups, none of the cups reconstructed with IBG were radiographically loose, in contrast to one cup in the non-IBG group which showed radiological loosening due to migration two years postoperatively. However, the position of the cup is stable and the patient experienced no complaints at the latest follow-up at 4.7 years. Fifty-one of a total of 55 non-revised cups were radiographically well incorporated and showed no radiolucent lines at final follow-up. One cup in the non-IBG group showed a non-progressive line which was present immediately post-operatively (zone 1, bone-cement interface) and two cups of the IBG group showed progressive radiolucent lines in one zone (one in the bone-cement interface in zone 1, the other in the bone-graft interface in zone 2), which were visible at 1 year and 1.5 years postoperatively, respectively. All three patients were doing clinically well. There were no radiographs showing osteolysis or migration in either group. 8

DISCUSSION

Based on our satisfying long-term experience with acetabular IBG in patients with bone defects,13, 14, 21-23 we realized that this technique might be an option to improve cup survival in young patients in acetabula without a bone defect as well. Although also some bone stock is reconstructed using these bone grafts, this was not the initial goal of the procedure, since none of these acetabula had pre-existing bone stock defects. None of the cups in the IBG group showed significant migration or aseptic loosening within two years postoperatively. There was one septic loosening in the whole group, and

153 Cemented total hip arthroplasty and impaction bone grafting in young patients

although it occurred in the IBG group, there is no suggestion of a relation between the use of the IBG technique and increased infection rates as this patient had received an autograft.22, 24 At two years, all cups except one (non-IBG) were radiographically stable. The current study is based on prospectively collected data, comparing two cohorts of young patients. The same surgeons were involved in both study groups, using the same implants and techniques. Additionally, follow-up radiographs were available for all patients. Unfortunately, this study is not a randomized trial, although the patient groups are comparable. The addition of a third control group of uncemented primary cups with IBG would certainly be of additional value to compare the treatments. In our institution we have no experience with uncemented prostheses and we therefore decided not to include this option in the current study. However, recent publications on uncemented THA’s in combination with IBG showed acceptable results as well.25, 26 There are potential drawbacks when applying this technique; a longer surgical time might be expected since IBG is an additional step during surgery. The surgical time was prolonged (on average 8 minutes) but within acceptable limits. Secondarily, early mechanical loosening of the cup that is cemented on top of the bone graft layer and poor incorporation of the bone grafts can occur. However, there were no revisions in the IBG group that were related to the IBG technique within two years. From histological studies it is known that these (auto)grafts tend to incorporate quickly,27-30 so after the period of two years it is not likely to expect problems of mechanical loosening. 8 The slightly prolonged postoperative rehabilitation time can be considered as a disadvantage as well. Based on our historical experience patients were allowed to 10% weight bearing the first six weeks postoperatively followed by six weeks of 50% weight bearing. These patients had larger acetabular reconstructions and the weight bearing limitation was necessary to allow the reconstruction to become stable. Realizing that the reconstructions in the current study are smaller, we have changed the postoperative weight bearing protocol in the meantime to immediate 50% weight bearing during the first six weeks. The weight bearing limitations in the IBG group did not have any influence on the use of LMWH which was prescribed for 6 weeks in both groups and no deep venous thrombosis or pulmonary embolism were observed in any of the groups.

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A new approach to improve cemented cup survival in primary total hip arthroplasty in young patients: acetabular impaction bone grafting

In the study, a relatively high number of revisions was performed due to recurrent dislocations. However, all three patients suffered from posttraumatic osteoarthritis and it is known that due to the trauma and previous surgeries, the soft tissues are not optimal, causing an impaired abductor muscle mechanism.31, 32 In addition, these patients are usually not familiar with limited hip joint excursions, and can subsequently be less cautious with postoperative movement restrictions. Perhaps, larger femoral head prostheses might solve this problem in this patient group. Acetabular impaction bone grafting in cases without a bone stock defect during the primary cemented THA is a new approach in an attempt to improve the cemented primary hip arthroplasty in young patients. In several studies, good long-term outcomes of acetabular IBG in both primary and revision THA have been reported. It is known both from animal studies and human clinical biopsies taken after IBG on the acetabular side that these grafts incorporate very well. In studies with less satisfying outcomes, the problematic cases were always the more demanding cases with segmental and cavitary defects. And although this approach is based on a new idea, the used technique itself is well-proven with published long term outcome data by several study groups. The focus of this extremely preliminary report was to report the complications of this technique within the first two years after implantation, as this method can result in a higher complication rate compared to the traditional method with direct cementation, which was not the case in this study group. This study emphasizes the fact that we will need to monitor the follow-up of this cohort closely in order to see if the results can match the results of our historical cohorts with acetabular defects on the long-term. Prospective 8 randomized studies comparing the techniques, with maybe even comparing uncemented and cemented cups with bone impaction in young patients, are needed to further analyze this new surgical protocol.

155 Cemented total hip arthroplasty and impaction bone grafting in young patients

REFERENCES

1. Eskelinen A, Remes V, Helenius I, Pulkkinen P, Nevalainen J, Paavolainen P. Uncemented total hip arthroplasty for primary osteoarthritis in young patients: a mid-to long-term follow- up study from the Finnish Arthroplasty Register. Acta Orthop 2006; 77: 57-70. 2. Duffy GP, Berry DJ, Rowland C, Cabanela ME. Primary uncemented total hip arthroplasty in patients <40 years old: 10- to 14-year results using first-generation proximally porous-coated implants. J Arthroplasty 2001; 16: 140-144. 3. Joshi AB, Porter ML, Trail IA, Hunt LP, Murphy JC, Hardinge K. Long-term results of Charnley low-friction arthroplasty in young patients. J Bone Joint Surg Br 1993; 75: 616-623. 4. Kim YH, Park JW, Patel C, Kim DY. Polyethylene wear and osteolysis after cementless total hip arthroplasty with alumina-on-highly cross-linked polyethylene bearings in patients younger than thirty years of age. J Bone Joint Surg Am 2013; 95: 1088-1093. 5. Lewthwaite SC, Squires B, Gie GA, Timperley AJ, Ling RS. The Exeter Universal hip in patients 50 years or younger at 10-17 years’ followup. Clin Orthop Relat Res 2008; 466: 324-331. 6. Makela KT, Eskelinen A, Pulkkinen P, Paavolainen P, Remes V. Results of 3,668 primary total hip replacements for primary osteoarthritis in patients under the age of 55 years. Acta Orthop 2011; 82: 521-529. 7. McAuley JP, Szuszczewicz ES, Young A, Engh CA, Sr. Total hip arthroplasty in patients 50 years and younger. Clin Orthop Relat Res 2004: 119-125. 8. Pedersen AB, Mehnert F, Havelin LI, Furnes O, Herberts P, Karrholm J, et al. Association 8 between fixation technique and revision risk in total hip arthroplasty patients younger than 55 years of age. Results from the Nordic Arthroplasty Register Association. Osteoarthritis Cartilage 2014; 22: 659-667. 9. Shia DS, Clohisy JC, Schinsky MF, Martell JM, Maloney WJ. THA with highly cross-linked polyethylene in patients 50 years or younger. Clin Orthop Relat Res 2009; 467: 2059-2065. 10. Sochart DH, Porter ML. The long-term results of Charnley low-friction arthroplasty in young patients who have congenital dislocation, degenerative osteoarthrosis, or rheumatoid arthritis. J Bone Joint Surg Am 1997; 79: 1599-1617. 11. Torchia ME, Klassen RA, Bianco AJ. Total hip arthroplasty with cement in patients less than twenty years old. Long-term results. J Bone Joint Surg Am 1996; 78: 995-1003.

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12. Wroblewski BM, Siney PD, Fleming PA. Charnley low-frictional torque arthroplasty in young rheumatoid and juvenile rheumatoid arthritis: 292 hips followed for an average of 15 years. Acta Orthop 2007; 78: 206-210. 13. Slooff TJ, Huiskes R, van Horn J, Lemmens AJ. Bone grafting in total hip replacement for acetabular protrusion. Acta Orthop Scand 1984; 55: 593-596. 14. Busch VJ, Gardeniers JW, Verdonschot N, Slooff TJ, Schreurs BW. Acetabular reconstruction with impaction bone-grafting and a cemented cup in patients younger than fifty years old: a concise follow-up, at twenty to twenty-eight years, of a previous report. J Bone Joint Surg Am 2011; 93: 367-371. 15. Askew MJ, Steege JW, Lewis JL, Ranieri JR, Wixson RL. Effect of cement pressure and bone strength on polymethylmethacrylate fixation. J Orthop Res 1984; 1: 412-420. 16. Azuma T, Yasuda H, Okagaki K, Sakai K. Compressed allograft chips for acetabular reconstruction in revision hip arthroplasty. J Bone Joint Surg Br 1994; 76: 740-744. 17. Krause WR, Krug W, Miller J. Strength of the cement-bone interface. Clin Orthop Relat Res 1982: 290-299. 18. MacDonald W, Swarts E, Beaver R. Penetration and shear strength of cement-bone interfaces in vivo. Clin Orthop Relat Res 1993: 283-288. 19. Conn R A PLFA, Stauffer R N, Ilstrup D. Management of acetabular deficiency: long-term results of bone grafting in the acetabulum in total arthroplasty. Trans Orthop Res Soc 1985; 9: 451-452. 20. DeLee JG, Charnley J. Radiological demarcation of cemented sockets in total hip replacement. Clin Orthop Relat Res 1976: 20-32. 8 21. de Kam DC, Gardeniers JW, Hendriks JC, Veth RP, Schreurs BW. Cemented polyethylene cups in patients younger than 40 years. Clin Orthop Relat Res 2009; 467: 1753-1764. 22. Schreurs BW, Slooff TJ, Gardeniers JW, Buma P. Acetabular reconstruction with bone impaction grafting and a cemented cup: 20 years’ experience. Clin Orthop Relat Res 2001: 202-215. 23. Schreurs BW, van Tienen TG, Buma P, Verdonschot N, Gardeniers JW, Slooff TJ. Favorable results of acetabular reconstruction with impacted morsellized bone grafts in patients younger than 50 years: a 10- to 18-year follow-up study of 34 cemented total hip arthroplasties. Acta Orthop Scand 2001; 72: 120-126.

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24. Welten ML, Schreurs BW, Buma P, Verdonschot N, Slooff TJ. Acetabular reconstruction with impacted morcellized cancellous bone autograft and cemented primary total hip arthroplasty: a 10- to 17-year follow-up study. J Arthroplasty 2000; 15: 819-824. 25. Lee JM, Nam HT. Acetabular revision total hip arthroplasty using an impacted morselized allograft and a cementless cup: minimum 10-year follow-up. J Arthroplasty 2011; 26: 1057- 1060. 26. Palm L, Jacobsson SA, Kvist J, Lindholm A, Ojersjo A, Ivarsson I. Acetabular revision with extensive allograft impaction and uncemented hydroxyapatite-coated implants. Results after 9 (7-11) years follow-up. J Arthroplasty 2007; 22: 1083-1091. 27. Buma P, Donk S, Slooff TJ, Schreurs W. Bone graft incorporation after reconstruction of bony defects with impacted morselized bone graft. Histology of animals and patients. Ortop Traumatol Rehabil 2001; 3: 41-47. 28. Garcia-Cimbrelo E, Cruz-Pardos A, Garcia-Rey E, Ortega-Chamarro J. The survival and fate of acetabular reconstruction with impaction grafting for large defects. Clin Orthop Relat Res 2010; 468: 3304-3313. 29. Schimmel JW, Buma P, Versleyen D, Huiskes R, Slooff TJ. Acetabular reconstruction with impacted morselized cancellous allografts in cemented hip arthroplasty: a histological and biomechanical study on the goat. J Arthroplasty 1998; 13: 438-448. 30. van der Donk S, Buma P, Slooff TJ, Gardeniers JW, Schreurs BW. Incorporation of morselized bone grafts: a study of 24 acetabular biopsy specimens. Clin Orthop Relat Res 2002: 131-141. 31. Schreurs BW, Zengerink M, Welten ML, van Kampen A, Slooff TJ. Bone impaction grafting 8 and a cemented cup after acetabular fracture at 3-18 years. Clin Orthop Relat Res 2005: 145- 151. 32. Makridis KG, Obakponovwe O, Bobak P, Giannoudis PV. Total hip arthroplasty after acetabular fracture: incidence of complications, reoperation rates and functional outcomes: evidence today. J Arthroplasty 2014; 29: 1983-1990.

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8

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Summary and general discussion

CHAPTER 9 Cemented total hip arthroplasty and impaction bone grafting in young patients

SUMMARY

The number of total hip arthroplasties performed in very young patients is increasing.1, 2 Over the last decade, different arthroplasty techniques have been used to treat these young patients, who mostly suffer from secondary osteoarthritis. Non-cemented, cemented, hybrid and reversed hybrid techniques are used and investigated. In addition, different bearings, including: metal-on-polyethylene; metal-on-metal; ceramic-on-ceramic; and ceramic-on-polyethylene have been used. Furthermore, an increasing number of young patients received a resurfacing hip arthroplasty. In contrast to conventional total hip arthroplasties (THA), the proximal femoral bonestock is preserved in resurfacing hip arthroplasty. The different techniques used in young patients have shown varying success rates. It is important in THA for very young people to use hip implants with a proven long- term outcome, as they will probably outlive their implant.3 Choosing an implant with an excellent and very reliable long-term outcome is one step to prevent early revisions. Alongside this, it must be kept in mind that most young people will inevitably face one or more revisions in their lifetime, due to their long life-expectancy. Therefore, the implant must also be revisable to avoid the creation of large bone stock deficiencies during revision surgery that involves attempts to remove the failed prostheses. Furthermore, outcome of the revision THA is thus influenced by the primary type of implant and the primary THA procedure. Respecting the bone stock, or even enhancing the amount of bone at time of the primary THA is of great importance for the future of the implant and any subsequent revisions in the young patients. Hence, both survival of the primary and subsequent revision THA and revisability of the implant are important outcome measurements in these young patients. 9 The main objective of this thesis was to evaluate the long-term results of the cemented primary and revision total hip arthroplasty in young patients under 50 years old. Furthermore, the long-term results of impaction bone grafting (IBG) in acetabular reconstructions in these young patients were evaluated. This technique includes reconstruction of the acetabulum with the help of auto- or allograft bone chips that are impacted with a metal hammer into the acetabular defect. Moreover, the next step of the application of impaction bone grafting was introduced. Nowadays, at Radboud university medical center (Radboudumc), Nijmegen, the

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Netherlands, IBG is also used in young patients without pre-existing bone deficiencies to enhance their cement-bone fixation by using an additional layer. Early results are analysed to evaluate the use of this technique in young patients without acetabular bone stock deficiency. Finally, literature was studied to investigate the amount of reliable information available regarding the long-term outcome of primary THA and the subsequent revision arthroplasty outcome in cohorts of younger patients. In order to reach the objective of this thesis, research questions were formulated and answered in the next chapters.

1. Resurfacing hip arthroplasty in younger patients: what is the state-of-the-art and what should we advise patients under 55 years of age?

Chapter 2 describes the developments, results and complications of the hip resurfacing arthroplasty. Hip resurfacing arthroplasty was re-introduced as an alternative to the conventional THA. Conventional THA showed suboptimal results in younger patients compared to elderly patients. This led to the demand and search for other solutions in this specific patient category. The resurfacing technique was widely adopted as the best solution for younger patients and its application enormously increased by the beginning of the 21st Century. A literature search, which we carried out in 2011, indicated that, at the time, not one randomised controlled trial with a minimum follow-up of 10 years, comparing hip resurfacing to conventional hip replacement, had been conducted in patients under 55 years of age. Independently, Australian- and United Kingdom Hip Registries demonstrated high revision rates for some brands of resurfacing implants after just five years. In addition to these disappointingly early revision rates, complications were increasingly reported, such as aseptic lymphocytic vasculitis, which was caused 9 by a local tissue reaction evoked by metal particles. The resurfacing procedure received negative media attention in the Netherlands, leading to confusion and concern amongst patients. In response to this, the Netherlands Orthopaedic Association (NOV) applied a moratorium that advised members not to use these implants until the status of these devices was clearer. The same advice was also given for large head metal-on-metal articulations in conventional THA. To reduce patient uncertainty in this kind of situation, it is important to provide information about the specific type of implant used in their case.

163 Cemented total hip arthroplasty and impaction bone grafting in young patients

2. What is the long-term outcome of a cemented total hip arthroplasty in patients under 30 years, and what is the outcome of subsequent revisions in this group of patients?

Resurfacing hip prostheses have never been used at Radboudumc. A cemented THA is our standard procedure for all cases, with additional bone impaction grafting used in the presence of acetabular bone stock deficiencies. This standard procedure is performed even in very young patients aged less than 30 years old at time of primary surgery.

In Chapter 3, we present the long-term outcome of the primary prosthesis in patients less than 30 years of age, along with the outcome of their subsequent revisions. This is an update of a series that was initiated in 1988. The study reports on 48 consecutive patients (69 hips), which were all treated with a cemented primary total hip prosthesis between 1988 and 2004.4 The mean age at time of surgery was 25 years (range 16 to 29 years).The mean follow-up of the primary THA was 11.5 years (range 7 to 23 years). In addition to the results of our primary total hip arthroplasties, a Kaplan-Meier survival analysis was conducted for the revisions in this group. During follow-up, 13 revisions were performed; in three cases a two-stage total revision was performed for septic loosening, in one case originally planned for one stage cup revision, positive cultures were found during cup revision and another nine cups were revised for aseptic loosening. Of these nine cups, seven were primary cemented hips without IBG, while there were only two revisions in the IBG group. All revisions required in this cohort were also executed with a cemented implant, and in all cases, except one, IBG was carried out. No aseptic stem revisions were performed. The 10- and 15-years survival rates with endpoint revision for aseptic loosening 9 of the primary THA were 90% (95% confidence interval (CI): 79-96) and 82% (95% CI: 65-92) respectively. The 13 revisions that were performed had a mean follow-up of seven years (range one to 15 years), and only one re-revision was performed 13 years after cup revision. Cemented total hip implants in patients under 30 years had an encouraging outcome at 10- and 15-years after surgery in these young patients. Combining this with IBG provides a durable and revisable solution for these very young patients, who will probably need future revisions, because they are likely to outlive their prostheses.

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3. Can the cemented highly polished Exeter stem be used as a long-term solution in patients under 40 years old?

Chapter 4 describes the long-term results of the ExeterTM (Stryker-Howmedica, Newbury, UK) cemented femoral component. This component has been used frequently since 1991 at Radboudumc, and from 1998 onwards, it is the standard stem used in every patient. We investigated all 104 cemented stems in 78 consecutive patients under the age of 40, who received a primary THA replacement between October 1993 and May 2004.5 The Exeter stems were combined with different types of cemented polyethylene acetabular components, and in case of an acetabular bone stock defect, IBG was performed. In one case, femoral IBG was added. Radiographic analyses showed that femoral radiolucent lines increased over time, but no relation to acetabular wear was found. At final follow- up, 16 out of 100 non-revised stems showed stable radiolucent lines in one or more Gruen zones. There was no increase in the number of radiographically loose femoral components and, therefore, only one of the surviving stems was considered radiographically loose. In total, three stems were revised for septic loosening after 2.2 years, 3.4 years and 6.1 years. In one patient, a stem fracture occurred after 16.5 years. The broken implant was removed and a new cemented stem was implanted. This same patient also suffered a contra-lateral Vancouver B1 peri-prosthetic fracture after a fall, 11.2 years post-surgery, which was treated with cable grip and plating. No revisions for aseptic loosening were performed for any of the stems during the full study period. This resulted in an estimated Kaplan-Meier survival at 10-years and 17-years of 97.1% (95% CI: 91.3-99.1) and 92.1% (95% CI: 74.1-97.8) for endpoint revision for any reason and 100% for aseptic loosening (95% CI: 83.8-100) both at 10-years and 17-years. The clinical outcome remained good. Therefore, we conclude that the use of cemented 9 Exeter femoral components is an acceptable treatment option for very young patients.

4. What are the 30-year radiographic and clinical outcomes of primary and revision acetabular reconstructions with impaction bone grafting in patients aged less than 50 years old?

165 Cemented total hip arthroplasty and impaction bone grafting in young patients

In Chapter 5, the update of 42 acetabular primary and revision reconstructions with IBG and a cemented cup is presented, as performed in 37 patients under 50 years old, now at 27-years to 35-years follow-up.6 No other studies on acetabular reconstructions in young patients presenting minimal 25-year follow-up are known in literature. Between 1979 and 1987, we performed 42 consecutive acetabular reconstructions (23 primary, 19 revisions) using the IBG technique and cemented cups. Radiographic and clinical parameters, including the Harris Hip Score (HHS) and the Oxford Hip Questionnaire Score (OHS), were collected prospectively. In the Kaplan-Meier survival estimation, we treat death as a censored observation. However, in fact, death is another competing endpoint, alongside revision. During long- term follow-up over 35 years, the number of patients who died throughout the study period, of course, increased. Therefore, the competing risk of death was incorporated by performing competing risk analyses (cumulative incidence function). To compare the cumulative incidence function of revision with the Kaplan-Meier survival analyses, we first calculated the estimated percentage of procedures revised as 1 – estimated survival percentage (1-KM). At a mean follow up of 30.3 years (range 27-35), one patient was lost to follow-up and seven patients died (nine hips). Radiographically, six of the 11 surviving acetabular reconstructions showed radiolucent lines in one or two zones of DeLee and Charnley. All of them were non-progressive and none of the 11 surviving reconstructions showed radiographic loosening. The mean HHS at time of review was 88 (range 58-99) and mean OHS was 20 (range 12-40). The Kaplan-Meier survival with revision for any reason as the end-point was 40% at 30 years (95% CI: 23-56), so the cumulative percentage of procedures revised (1-KM) was 60% (95% CI: 44-77). The competing risk analysis showed the cumulative incidence 9 function of revision in the presence of death (CIF) was 51% (95% CI: 33-65) at 30-years. This illustrates that the Kaplan-Meier survival analysis results in an overestimation of revision for any reason at 30-years follow-up by 18%. The Kaplan-Meier survival with revision for aseptic loosening as the end-point was 56% (95% CI: 35-73) at 30-years, resulting in cumulative failure incidence (1-KM) of 44%. The competing risk analysis for end-point revision for aseptic loosening showed a cumulative failure incidence of 36% (95% CI: 17-51) at 30-years. These long-term results illustrate that this technique shows acceptable results when used in demanding primary THA and acetabular revisions and supports the use of IBG

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Summary and general discussion as a long-term solution in young patients with acetabular bone defects. The study also shows that a competing risk analysis is a better method to calculate the risk for patients of having future revisions in the very long-term follow-up studies.

5. What are the clinical- and radiographical outcomes of the Contemporary acetabular component in patients under 50 years old, with and without IBG?

Over the past few years, increased attention has been drawn to the importance of a strict follow-up of newly introduced implants, as well as to the long-term results of implants that are currently used all over the world. One of these implants is the polyethylene Exeter Contemporary cup (Stryker -Howmedica, Newbury UK), which has been on the market for nearly 20 years, and has been used in young patients at our institution for over 15 years. This cup has two subtypes: the Contemporary hooded and the Contemporary flanged cup. No long-term results for young patients are described in the literature. In Chapter 6, we report the mid-term clinical- and radiographical results of the cemented polyethylene Contemporary cup in primary THA in patients aged less than 50 years old. In the period between January 1999 and January 2006, 152 polyethylene Exeter Contemporary cups were used, with and without acetabular IBG, in 126 patients aged less than 50 years old. At mean follow-up of 7.6 years (0.9 to 12.0), one patient was lost to follow-up. All clinical questionnaire scores (HHS, OHS and Visual Analogue Scale scores for pain in rest, pain during activity and satisfaction) had improved. Radiological follow- up was complete for 146 implants and showed an eight-year survival for the endpoint radiological loosening of 93.1% (95% CI: 86.2-96.6). Eight cups were revised: five due to aseptic loosening after 1.1 years, 2.5 years, 3.1 years, 5.0 years and 6.0 years post- operatively. One Contemporary hooded cup was revised for recurrent luxations at 3.5 9 years and one cup showed post-traumatic loosening after 4.3 years. One Contemporary hooded cup without IBG was revised as part of a complete THA revision for septic loosening at 0.9 years. This resulted in a survival of the cups with revision for any reason as the endpoint of 94.4% (95% CI: 89.2-97.2) at eight years, whereas the survival of the cups with reason for revision aseptic loosening was 96.4% (95% CI: 91.6-98.5). The high dislocation rate of 5.6% that was seen in the group of patients treated with the Contemporary hooded cups led Radboudumc to switch to the use of only the Contemporary flanged cups, as it became apparent that the hooded design might cause

167 Cemented total hip arthroplasty and impaction bone grafting in young patients

more dislocations. The large posterior rim elevation seems to function as a source of impingement, resulting in a higher dislocation rate. It is remarkable that these cups, which were specifically designed with an elevated posterior rim in an attempt to reduce the dislocation rate, in fact, generated more dislocations.

6. What is known of both the survival data of primary THA and the survival of the subsequent revisions within the same cohorts of patients under 50 years of age?

Chapter 7 describes the results of a systematic review of the available reports in literature that describe cohorts of patients with both their survival of the primary implant reported at a mean follow-up of ten years, as well as the results of subsequent revisions of these same patients. In young patients it is very important to know the influence of the outcome of primary arthroplasty on the outcome of subsequent revision arthroplasty and the expected survival of these revision arthroplasties. So far, most publications concerning revisions of THA in younger patients include selectively included revision cases performed during a particular period of time. Results of these revisions are often published without detailed information on the characteristics of the patients and primary implants within the patient cohort. Furthermore, often only survival of one component is presented which does not reflect the total risk of re-operation for a patient. This can result in selective outcome reporting for revision THA, which might lead to incomplete information of the success of THA in younger patients and inaccurate decision-making. When reporting on revision THA, one should include the survival results of both THA components and baseline characteristics of the complete primary THA cohort to gain accurate information on which revision THA could be most successful for an 9 individual patient. A literature search was performed to check for the availability of this kind of information. The study was performed according to the PRIMSA guidelines. Medline, Embase and the Cochrane Library were searched up to the 13th of April 2016 was performed to find any studies that reported both the survival of primary and the survival of subsequent revision THA in single cohorts of patients younger than 50 years old. Studies were eligible if they investigated and reported on cohorts of patients who had received their primary THA at an age of younger than 50 years old, and if they included the survival outcome of subsequent revisions of the same cohort. Two independent reviewers assessed study eligibility and quality.

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Summary and general discussion

Kaplan-Meier analysis or competing risk analysis for revision for any reason should be described both for the primary THA at a mean follow-up of 10-years and the subsequent revision total hip arthroplasties that were performed within the same cohort. A total of 4,799 unique records were found, of which 43 were possibly eligible, but only one met our inclusion criteria. In conclusion, there is a clear lack of evidence for the revision arthroplasty outcome in young patients. With an increasing number of young patients receiving a THA nowadays, we might face large numbers of patients in the future, who have most likely not received optimal primary and revision treatment, and as a result, have no further reconstructive options after failed hip arthroplasty. This will leave society with an increasingly costly medical burden.

7. Can we safely use impaction bone grafting in patients without an acetabular defect in order to improve future long-term outcome?

Finally, Chapter 8 focuses on a new concept aimed at improving cup survival in patients under 50 years old, as the cup remains the ‘weakest link’ in THA. Based upon the good clinical results of IBG seen in younger patients throughout the years, we introduced IBG in patients without an acetabular defect. We believe that the application of acetabular IBG in primary cemented THA’s will improve bone-cement interdigitation and, thereby, improve cup survival, even in absence of acetabular bone stock loss. Although also some bone stock is added using IBG, this is not the initial goal of the procedure. The aim of the study described in chapter 8, was to evaluate the difference in revision rate and early complications between patients under the age of 50 years without an acetabular defect, who received a straightforward primary cemented THA without IBG or a cemented THA with acetabular IBG. Therefore we compared two cohorts of patients: 9 hips without an acetabular defect, that received a cemented cup without IBG (non-IBG group, n = 30) in the period of 1-1-2006 up to 2008 and hips without an acetabular defect that received a cemented cup after a layer of impacted bone grafts (IBG group, n = 29) in the period from 1-1-2008 up to 2010. All surgeries were performed by three orthopedic surgeons and a posterolateral approach was used in all cases. To optimize direct cementation (non-IBG group) or to stimulate vascularisation of the graft (IBG group), the acetabular bone bed was prepared with multiple two-millimeters drillholes. After washing and drying of the acetabulum the cups of the non-IBG group were directly

169 Cemented total hip arthroplasty and impaction bone grafting in young patients

cemented onto the surface of the acetabulum. In the IBG group, autografts of the patients’ femoral head, allografts or a combination was used to create bone chips (7-10 mm size) which were impacted with a metal impactor and mallet. Vacuum mixed cement was pressurized directly into the host bone or impacted grafts and the acetabular component was inserted. Patients were allowed 10% of partial weight bearing in the first 6 weeks, followed by 50% weightbearing in the next 6 weeks. The two cohorts of patients showed no statistical difference in patients characteristics. Mean age at index surgery was 36.2 (15.3-49.4) years. At time of review one patient (non-IBG) was lost to follow-up after 0.47 years due to emigration. None of the patients died and the minimal follow-up was 2 years. Radiological and clinical parameters were assessed. Kaplan-Meier survival analyses were used to determine the survivorship of the acetabular component. No intra-operatieve complications related to the placement of the cups occurred. The mean additional surgery time was 8 minutes in the IBG group. Survival for endpoint revision for any reason for the non IBG group was 96.7% (95% CI: 78.6-99.5) and for the IBG group 93.1% (95% CI: 75.1-98.2) at two years. Three acetabular components were revised due to recurrent dislocations (one in the non-IBG group and two in the IBG group). All three patients suffered from early osteoarthritis after a pelvic trauma. One revision (IBG group) was performed for septic loosening. The two-year acetabular survivorship with endpoint revision for aseptic loosening was 100% in both the non-IBG and IBG group. Of the 55 non revised cups, one cup (non IBG group) showed radiological loosening. Furthermore in the non IBG group one cup showed a non progressive radiolucent line in acetabular zone 1, and 2 cups in de IBG group showed progressive lines in one acetabular zone. This new approach might be an attractive solution for younger patients suffering from end-stage osteoarthritis. Intensive monitoring will be necessary, however, to evaluate 9 long-term results and to check for technical advantages during the revision surgery in the future. In addition, studies with larger numbers are needed. Prospective randomised studies comparing the technique are needed to further analyse the long-term advantages.

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Summary and general discussion

GENERAL DISCUSSION

There is a worldwide trend to implant more total hip arthroplasties in patients aged less than 50 years old. Whereas the number of cemented THA performed in these young patients is decreasing, the number of uncemented total hip arthroplasties performed is increasing7. High revision rates were seen for uncemented metal-on-metal bearings.8,9 However, for metal-on-polyethylene bearings, the survival results for the primary cemented and uncemented THA after 10 years are, in general, comparable.8, 10 What exactly happens after these first 10 years is unclear and information regarding technically demanding cases and subsequent revision outcomes is not widely available. In this thesis, the long-term results of a cemented THA and IBG after these first 10 years were investigated. In the very young patients (under the age of 30), who received a cemented total hip and in case of a bone stock defect also received IBG, we found a 10-years and 15-years survival rate with endpoint revision for aseptic loosening of the primary total hip of 90% and 82%, respectively. This survival rate is still lower compared to the general survival rates seen in cemented- and uncemented THA in many Hip Arthroplasty Registries and the Orthopaedic Data Evaluation Panel (ODEP) criteria for THA in general, which also includes older patients,1, 7, 8, 10, 11 but is comparable to other data for these young patients. However, in addition to survival, one more important aspect that should be taken into account in treating the young patient: the revisability of the prosthesis. Cemented total hip arthroplasties have acceptable long-term survival results in young patients that suffer from end-stage osteoarthritis, who require technically demanding reconstructions of the hip joint. Therefore, orthopaedic surgeons should be able to perform 9 a well-cemented THA using the third generation technique. A reduction of the technical skills required to perform a proper cemented THA within the orthopaedic community would be regrettable. This thesis also proves that revision of cemented components can be well performed with re-cemented components, even in the case of technically demanding hips, as included in this thesis. Besides fixation technique, bone stock plays an important role in revisability of the prosthesis. The restoration of bone stock deserves attention. Young patients will most likely outlive their primary prosthesis and the residual bone stock left after removal of the

171 Cemented total hip arthroplasty and impaction bone grafting in young patients

failed primary THA can influence the technical aspect and survival results of the revision procedure. In such cases, acetabular IBG is an attractive biological way to reconstruct the bone stock already at their primary total hip implant. To achieve satisfying results, attention must be paid during the procedure to use the adequate size of bone chips (8- 12mm) and to perform the correct technique of impacting the bone chips. Small variations on the original technique may lead to inferior clinical outcomes. In contrast to techniques that use large metal cups, metal wedges or large cages,12 it can be used in combination with thin metal wire meshes in almost all kinds of defects. The only exception mentioned in literature is for very large defects, which seem to have less successful results.13 Other techniques that can be used in the presence of a bone stock deficiency at the primary implantation like bulk grafts used during primary THA have also been described, but the outcome of revisions with such bulky grafts are not yet available.14 So far, it remains unclear if these reconstructions with bulk grafts really produce more bone and facilitate a further hip revision. By restoring the bone stock in cases of primary- and secondary acetabular reconstructions, we try to optimise the bone-cement interface, but also to create an optimal situation for expected future revisions. In our primary- and revision reconstructions with a cemented THA and IBG in patients under 50 years old, 56% survival was seen for the endpoint aseptic loosening at 30-years of follow-up, which is a unique result. This thesis shows that revisions of cemented THA’s, with or without acetabular reconstruction, can be performed with a cemented THA and IBG. Even in the absence of a bone stock deficiency, IBG may still be added to the acetabular bone bed in order to enhance cement-bone fixation. Our cohort study showed no increased risk of early complications between both cohorts. No early aseptic loosening 9 was seen on the radiographs in the IBG group. These are the first results of IBG and a primary cemented THA in young patients without an acetabular defect. Currently, we are collecting and evaluating results from a larger number of patients, and to determine the exact behaviour of the grafts in these patients, histological studies should be performed, as radiographic evaluation of the grafts is not always very reliable. This thesis also aimed at careful evaluation of the presence of radiographical signs of loosening of the cemented components, such as radiolucent lines and osteolysis. In literature, the presence of radiolucent lines and osteolysis varies widely, illustrating the difficulty of comparing radiographic outcomes. These different observations might be

172 CHAPTER 9

Summary and general discussion due to different cup designs, the use of other criteria for reporting radiolucent lines or osteolysis, or a missing number of recent radiographs. All of our studies have no- or low numbers of patients lost to follow-up, and the criteria for radiographic analysis have always been the same throughout the years. We realise that in some studies we reported relatively high numbers of radiographic signs, such as osteolysis and radiolucent lines, compared to others. Interestingly, those lines often become stable radiolucent lines and no accelerated decline in survival of both acetabular and femoral components was noticed after 10-years of follow-up. Regarding the Exeter femoral stem, we observed an evidently higher number of radiolucent lines around the femoral components, compared to the 9.8% mentioned by Lewthwaite et al15 in their cohort of Exeter Universal stems in young patients. However, these radiolucent lines were often present in only one or two of all Gruen zones, and none of them progressed further to aseptic loose components. No relation to wear of the polyethylene acetabular component was seen. Observations like these should be closely monitored in the future to check for any increase in radiographic loosening. Another interesting aspect revealed in this thesis is the influence of the design of an acetabular component on the risk of luxation. This observation stopped us using Contemporary hooded cups in our patients. Such observations can only be performed by adequate monitoring of implants. This is another illustrative example of important information that can be collected from cohort studies. It confirms the important conclusion that newly introduced implants should be carefully monitored during early stages for their long-term results and revisability. Overall, a cemented THA in combination with acetabular IBG results in a biological reconstruction of the bone stock, and in case of long-term failure, revision is possible with a cemented cup and IBG. 9

CONCLUSION AND RECOMMENDATIONS

This thesis proves that satisfying long-term results of the cemented total hip arthroplasties in young patients can be expected, when performed with adequate third generation cementing techniques, and, if needed, in combination with IBG. Based on the results in patients with acetabular bone deficiencies, we expect that there might be an indication to

173 Cemented total hip arthroplasty and impaction bone grafting in young patients

use the IBG technique, even in young patient cases without acetabular bone deficiencies, as it can improve the bone-cement interface. At short-term follow-up, no additional risks of adding IBG to the procedure in the absence of an acetabular bone deficiency were found. However, further research is needed to prove the expected increase of the long-term survival of these fixations in young patients without an acetabular defect. In addition, it would be interesting to know if this technique can improve long-term patient satisfaction. Lastly, this thesis introduced the first step towards reporting the results of THA in young patients in a new way. This includes combining the outcome of the primary arthroplasty and the outcome of subsequent revisions within the cohort, which is essential information for younger patients who will most likely outlive their prosthesis. Future research must put more emphasis on combining these results and try to identify factors that positively or negatively influence the results of revision surgery. We need the best evidence that we can get to inform young osteoarthritic hip patients as accurately as possible, before he or she receives a THA surgery. In the future, we propose that research should be focused on: • the long-term survival of acetabular component in combination with impaction bone grafting in case of absence of an acetabular bone stock defect at primary surgery; • ‘patient-reported outcome measurements’ (PROMs) including long-term satisfaction and activity levels of patients receiving impaction bone grafting without any acetabulary defect; • cost-effectiveness analysis of adding impaction bone grafting to the total hip arthroplasty procedure in young patients without any acetabulary deficiency; • the revisability of primary components and the influence of the bone stock 9 available at revision surgery.

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REFERENCES

1. LROI Report 2014. Arthroplasty in the Picture. Annual Report of the Dutch Arthroplasty Register 2014. 2. Kurtz SM, Ong KL, Lau E, Bozic KJ. Impact of the economic downturn on total joint replacement demand in the United States: updated projections to 2021. J Bone Joint Surg Am. 2014;96(8):624-30. 3. McAuley JP, Szuszczewicz ES, Young A, Engh CA, Sr. Total hip arthroplasty in patients 50 years and younger. Clinical orthopaedics and related research. 2004(418):119-25. 4. Busch V, Klarenbeek R, Slooff T, Schreurs BW, Gardeniers J. Cemented hip designs are a reasonable option in young patients. Clinical orthopaedics and related research. 2010;468(12):3214-20. 5. de Kam DC, Klarenbeek RL, Gardeniers JW, Veth RP, Schreurs BW. The medium-term results of the cemented Exeter femoral component in patients under 40 years of age. The Journal of bone and joint surgery British volume. 2008;90(11):1417-21. 6. Busch VJ, Gardeniers JW, Verdonschot N, Slooff TJ, Schreurs BW. Acetabular reconstruction with impaction bone-grafting and a cemented cup in patients younger than fifty years old: a concise follow-up, at twenty to twenty-eight years, of a previous report. J Bone Joint Surg Am. 2011;93(4):367-71. 7. The Swedish Hip Arthroplasty Register Annual Report 2014. 2014. 8. 12th Annual Report 2015 National Joint Registry for England, Wales, Northern Ireland and the Isle of Man. 9. Furnes O, Paxton E, Cafri G, Graves S, Bordini B, Comfort T, et al. Distributed analysis of hip implants using six national and regional registries: comparing metal-on-metal with metal- on-highly cross-linked polyethylene bearings in cementless total hip arthroplasty in young 9 patients. J Bone Joint Surg Am. 2014;96 Suppl 1:25-33. 10. Australian Orthopaedic Association National Joint Replacement Registry. Annual Report. Adelaide: AOA;2015. 11. ODEP Orthopaedic Data Evaluation Panel. ODEP Criteria [updated Version November 2015last accessed 25th September 2016]. Available from: http://www.odep.org.uk/ ODEPRatings/ODEPCriteria.aspx. 12. Noordin S, Masri BA, Duncan CP, Garbuz DS. Acetabular bone loss in revision total hip arthroplasty: principles and techniques. Instructional course lectures. 2010;59:27-36.

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13. Garcia-Cimbrelo E, Cruz-Pardos A, Garcia-Rey E, Ortega-Chamarro J. The survival and fate of acetabular reconstruction with impaction grafting for large defects. Clinical orthopaedics and related research. 2010;468(12):3304-13. 14. Abdel MP, Stryker LS, Trousdale RT, Berry DJ, Cabanela ME. Uncemented acetabular components with femoral head autograft for acetabular reconstruction in developmental dysplasia of the hip: a concise follow-up report at a mean of twenty years. J Bone Joint Surg Am. 2014;96(22):1878-82. 15. Lewthwaite SC, Squires B, Gie GA, Timperley AJ, Ling RS. The Exeter Universal hip in patients 50 years or younger at 10-17 years’ followup. Clinical orthopaedics and related research. 2008;466(2):324-31.

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CHAPTER 10 Cemented total hip arthroplasty and impaction bone grafting in young patients

SAMENVATTING

Het aantal totale heupprothesen dat geplaatst wordt bij jonge patiënten neemt toe. In de laatste decennia zijn verschillende prothesiologietechnieken gebruikt om deze jonge patiënten, met vaak secundaire artrose van de heup (coxartrose), te behandelen. Ongecementeerde, gecementeerde, hybride en omgekeerd hybride technieken zijn gebruikt en onderzocht. Ook werd er door de jaren heen gebruik gemaakt van verschillende articulaties zoals metaal op polyethyleen, metaal op metaal, keramiek op keramiek en keramiek op polyethyleen. Daarnaast werd er de laatste jaren in toenemende mate de zogenaamde ‘resurfacing prothesen’ geplaatst in de jonge patiënt. In tegenstelling tot de conventionele totale heupprothese (THP) wordt hierbij het proximale femur intact gelaten. De genoemde technieken hebben allen verschillende overlevingsduuruitkomsten. Het is bij jonge patiënten zeer belangrijk om implantaten met een bewezen goede langetermijnuitkomst te gebruiken. Gelet op de nog lange levensduurverwachting van de jonge patiënt dient men er tevens rekening mee te houden dat de patiënt vaak zijn implantaat overleeft. Om deze reden dient het implantaat niet alleen een lange levensduur te hebben maar ook makkelijk te reviseren te zijn, zonder grote botdefecten te veroorzaken. Bovendien worden de uitkomsten van het revisie-implantaat beïnvloed door het type primaire implantaat en de operatieprocedure. Het respecteren of, indien nodig, het herstellen van aanwezige botconfiguratie ten tijde van de primaire THP is belangrijk voor de toekomst van het implantaat en de revisie-operaties in de jonge patiënt. Zowel de overlevingsduur van het primaire implantaat als van het revisie-implantaat zijn dan ook samen bepalende uitkomst-parameters in deze jonge patiënten. Het primaire doel van dit proefschrift was het evalueren van de langetermijnresultaten van gecementeerde primaire en revisie-THP in patiënten jonger dan 50 jaar. Daarnaast werden de resultaten van impaction bone grafting (IBG) in kaart gebracht. Met deze techniek wordt het acetabulum gereconstrueerd met behulp van autologe of donor 10 spongieuze botsnippers welke worden geïmpacteerd. Bovendien werd de volgende stap in de toepassing van IBG beschreven. Sinds 2008 werd in het Radboudumc te Nijmegen de IBG techniek ook standaard toegepast bij patiënten jonger dan 50 die geen acetabulair botdefect hebben maar wel in aanmerking komen voor een THP. Het doel was de cement-botfixatie te verbeteren door deze extra laag geïmpacteerde botsnippers. De korte-termijnresultaten werden geanalyseerd om het gebruik van de techniek bij jonge

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Nederlandse samenvatting en algemene discussie patiënten op deze wijze te evalueren. Ten slotte werd door middel van een literatuurstudie geïnventariseerd wat er reeds bekend is over de overlevingsresultaten van primaire THP’s gecombineerd met de overlevingsresultaten van de daaropvolgende revisie-THP’s in dezelfde patiënten. Om het primaire doel te behalen werden onderzoeksvragen geformuleerd en achtereenvolgens in de beschreven hoofdstukken beantwoord:

1. De resurfacing prothese in de jonge patiënt: wat is de stand van zaken en wat kunnen we patiënten jonger dan 55 jaar adviseren?

De ontwikkelingen, resultaten en complicaties van de resurfacing heupprothese wordt beschreven in hoofdstuk 2. De resurfacing heupprothese werd geherintroduceerd als alternatief voor de totale heupprothese. In vergelijking met oudere patiënten, liet de conventionele THP bij jongere patiënten tegenvallende resultaten zien. Daardoor ontstond er vraag naar andere oplossingen voor de jongere patiënten. De resurfacing heupprothese werd al snel gezien als dé oplossing voor deze doelgroep en in het begin van de 21e eeuw werd deze dan ook in een sterk toenemende mate toegepast. Bij ons literatuuronderzoek in 2011 werd geen studie aangetroffen waarin de resultaten van de resurfacing heupprothese met de conventionele heupprothese werden vergeleken in een gerandomiseerd onderzoek met controlegroep bij patiënten jonger dan 55 jaar en een minimale follow-up-duur van 10 jaar. Voorts lieten verschillende heupregistraties, waaronder het Australische en het Engelse heupregister, hoge revisie-aantallen zien van enkele typen resurfacing heupprothesen slechts 5 jaar na implantatie. Naast de tegenvallende overlevingsduur van enkele merken van dit type prothesen bleken er ook complicaties zoals aseptic lymphocytic vasculitis te ontstaan. Deze werden veroorzaakt door losse metaaldeeltjes afkomstig van de prothese die een lokale weefselreactie initieerden. In Nederland kwam de resurfacing prothese daardoor uiteindelijk negatief in het nieuws, leidend tot verwarring en ook zorgen 10 onder patiënten. In reactie hierop heeft de Nederlandse Orthopaedische Vereniging (NOV) besloten haar leden het advies te geven deze prothesen niet meer standaard te gebruiken totdat er meer over dit type en mogelijke complicaties bekend zou zijn. Indien een dergelijke situatie zich voordoet is het van groot belang om de patiënt correct te informeren over het type implantaat dat bij hem of haar is gebruikt.

181 Cemented total hip arthroplasty and impaction bone grafting in young patients

2. Wat is de langetermijnuitkomst van een gecementeerde totale heupprothese in patiënten jonger dan 30 jaar en wat is de uitkomst van de daaropvolgende revisie- implantaten in deze groep patiënten?

In het Radboudumc is de resurfacing prothese nooit gebruikt. Door de jaren heen is de standaard techniek altijd een gecementeerde THP geweest. Indien tevens een acetabulair botdefect aanwezig was, werd aanvullend IBG toegepast. Ook in het geval van hele jonge patiënten (<30 jaar) is dit de standaardprocedure. In hoofdstuk 3 evalueren we de langetermijnuitkomsten van de primaire THP bij patiënten jonger dan 30 jaar. Tevens presenteren we de uitkomsten van daaropvolgende revisie-implantaten bij dezelfde patiënten. De studie betreft een vervolgstudie van een onderzoekscohort dat werd gevolgd vanaf 1988. De studie includeert 48 opeenvolgende patiënten (69 heupen) die allemaal behandeld werden met een gecementeerde THP in de periode 1988-2004. De gemiddelde leeftijd ten tijde van de primaire operatie was 25 jaar (range 16 tot 29 jaar). De gemiddelde follow-up-duur van de primaire THP was 11.5 jaar (range 7 tot 23 jaar). Alle revisie-operaties die werden uitgevoerd in dit cohort, werden wederom uitgevoerd met een gecementeerde THP en in de meeste gevallen werd ook IBG toegepast. Er werd een Kaplan-Meier survival analyse verricht voor de overleving van zowel de primaire als de revisie-implantaten in dit cohort. Gedurende de follow-up-duur werden 13 revisie-operaties uitgevoerd: een drietal ‘two-stage’ totale revisie-operaties in verband met septische loslating, één geplande cuprevisie voor aseptische loslating waarbij toch positieve kweken werden gevonden tijdens cuprevisie en nog negen cuprevisies voor aseptische loslating. Zeven hiervan waren primaire heupprothesen zonder de toevoeging van IBG, terwijl bij slechts twee van deze revisie-operaties IBG was toegepast ten tijde van de primaire operatie. Er werden geen stelen voor aseptische loslating gereviseerd. De 10- en 15- jaars overleving voor het eindpunt revisie voor aseptische loslating van de primaire THP waren respectievelijk 90% (95% confidence interval (CI): 79-96) en 82% 10 (95% CI: 65-92). De 13 revisie-operaties die werden uitgevoerd hadden een gemiddelde follow-up-duur van zeven jaar (range 1 tot 15 jaar). Slechts één re-revisie-operatie werd 13 jaar na een eerdere cupvervanging uitgevoerd. Gecementeerde THP’s in patiënten jonger dan 30 jaar laten goede resultaten zien na 10 en 15 jaar. In combinatie met IBG kan een duurzame oplossing geboden worden aan de jonge patiënt die in de toekomst mogelijk nog een revisie-operatie moet ondergaan gezien zijn lange levensverwachting.

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3. Kan de gecementeerde gepolijste Exeter-steel gebruikt worden als een langetermijnoplossing in patiënten jonger dan 40 jaar?

Hoofdstuk 4 beschrijft de langetermijnresultaten van de gecementeerde ExeterTM steel (Stryker-Howmedica, Newbury, UK). Sinds 1991 werd deze femorale component vaak gebruikt in het Radboudumc te Nijmegen. Vanaf 1998 is het de standaard gebruikte femorale component voor iedere patiënt. Voor deze vervolgstudie werden alle 104 gecementeerde stelen in 78 opeenvolgende patiënten die een THP kregen tussen oktober 1993 en mei 2004 onder de leeftijd van 40 jaar, geïncludeerd. De Exeter-steel werd gecombineerd met verschillende typen gecementeerde polyethyleen acetabulaire componenten en in het geval van een acetabulair botdefect, werd IBG uitgevoerd. Eenmaal werd ook femorale IBG toegevoegd. De röntgenopnamen lieten gedurende de follow-up-duur een toename van femorale radiolucente lijnen zien. Aan het einde van de follow-up-duur lieten 16 van de 100 niet-gereviseerde stelen stabiele radiolucente lijnen zien in één of meer Gruen zones. Deze vertoonden geen verband met het optreden van polyethyleen wear van de cup. Er was geen toename in het aantal radiografisch losse stelen ten opzichte van de eerdere studie en dus bleef het bij één radiologisch loszittende steel. Er werden in totaal drie stelen gereviseerd voor septische loslating en wel na 2.2, 3.4 en 6.1 jaar. In één patiënt trad er een steelfractuur op na 16.5 jaar. Het gebroken implantaat werd verwijderd en een nieuwe steel werd geïmplanteerd. Dezelfde patiënt liep aan de contralaterale zijde een Vancouver B1 peri-prosthetische fractuur op na een val, 11.2 jaar na de operatie, welke werd behandeld middels een trochantergripplaat en kabels. Er werden geen revisie-operaties voor aseptische loslating uitgevoerd gedurende de gehele follow-up-duur. Dit resulteerde in een geschatte Kaplan-Meier survival na 10 en 17 jaar van respectievelijk 97.1% (95% CI: 91.3-99.1) en 92.1% (95% CI: 74.1-97.8) voor eindpunt revisie om welke reden dan ook en een 100% overleving voor aseptische loslating (95% CI: 83.8-100) zowel na 10 als 17 jaar. Ook de klinische uitkomsten bleven 10 goed. Daarom concluderen we dat de gecementeerde Exeter femorale component een acceptabele behandelingsmogelijkheid is voor de jonge patiënt.

4. Wat zijn de radiologische en klinische uitkomsten van acetabulaire primaire en revisie reconstructies met IBG na 30 jaar follow-up-duur in patiënten onder de 50 jaar?

183 Cemented total hip arthroplasty and impaction bone grafting in young patients

In Hoofdstuk 5 presenteren we de update van 42 acetabulaire primaire en revisie- reconstructies met IBG en een gecementeerde cup, uitgevoerd in 37 patiënten jonger dan 50 met een follow-up-duur van 27 tot 35 jaar. Er zijn geen andere studies bekend waarin de uitkomsten van acetabulaire reconstructies in jonge patiënten na een minimale follow-up-duur van 24 jaar worden beschreven. Tussen 1979 en 1987, werden in het Radboudumc 42 opeenvolgende acetabulaire reconstructies (23 primaire en 19 revisies) uitgevoerd met behulp van IBG en gecementeerde cups. De radiologische en klinische parameters inclusief de Harris Hip Score (HHS) en de Oxford Hip Questionnaire Score (OHS) werden prospectief verzameld. In de Kaplan-Meier survival analyse wordt overlijden als een censored event meegenomen. Maar eigenlijk is overlijden in feite een ander mogelijk competing eindpunt naast revisie van de prothese. Gedurende de lange follow-up-duur was uiteraard ook het aantal overleden patiënten toegenomen. Daarom werd naast de Kaplan-Meier survival analyse ook een competing risk analyse uitgevoerd (cumulative incidence function). Om de cumulative incidence function te kunnen vergelijken met de Kaplan-Meier (KM) survival analyse berekenden we eerst het geschatte percentage van gereviseerde prothesen als 1-KM. Na een gemiddelde follow-up-duur van 30.3 jaar (range 27-35 jaar) was er één patiënt lost-to-follow-up en waren zeven patiënten (negen heupen) overleden. Radiologisch lieten zes van de 11 overlevende acetabulaire reconstructies radiolucente lijnen zien in éen of twee zones van DeLee and Charnley. Deze waren allemaal niet- progressief en geen van deze 11 reconstructies liet radiografische loslating zien. De gemiddelde HHS ten tijde van review was 88 (range 58-99) en de gemiddelde OHS was 20 (range 12-40). De Kaplan-Meier overleving voor het eindpunt revisie om welke reden dan ook was 40% (95% CI: 23-56) na 30 jaar. Het cumulatieve percentage gereviseerde prothesen (1- KM) was dus 60% (95% CI: 44-77). De competing risk analyse liet zien dat de revisie- vrije overleving gebaseerd op het cumulatieve revisie-risico voor het eindpunt aseptische 10 loslating na 30 jaar 51% (95% CI: 33-65) was. De Kaplan-Meier overleving voor het eindpunt revisie voor aseptische loslating was 56% (95% CI: 35-73) na 30 jaar. Dit resulteert in een cumulatief revisiepercentage (1- KM) van 44%. De competing risk analyse voor het eindpunt aseptische loslating liet een cumulatief revisiepercentage zien van 36% (95% CI: 17-51) na 30 jaar.

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Deze langetermijnresultaten illustreren dat deze techniek, welke wordt toegepast in uitdagende primaire THP’s en acetabulaire revisies, acceptabele uitkomsten laat zien. Ze ondersteunen het gebruik van IBG als een langetermijnoplossing in jonge patiënten met acetabulaire botdefecten. Ook laat deze studie zien dat de Kaplan-Meier survival analyse de kans op falen met 18% overschat voor dit eindpunt en dat de competing risk analyse in dergelijke situaties dus een geschiktere analyse is.

5. Wat zijn de klinische en radiologische uitkomsten van de Exeter Contemporary cup in patiënten jonger dan 50 jaar met en zonder IBG?

Gedurende de laatste jaren heeft het strikt vervolgen van nieuw geïntroduceerde implantaten in toenemende mate aandacht gekregen. Ook is er steeds meer aandacht voor de langetermijnresultaten van implantaten die momenteel wereldwijd gebruikt worden. Eén van deze implantaten is de polyethyleen Contemporary cup (Stryker - Howmedica, Newbury UK), welke al 20 jaar lang op de markt is en in het Radboudumc ten tijde van de studie al meer dan 15 jaar werd gebruikt. Deze cup kent twee varianten: de hooded en de flanged variant. In de literatuur zijn echter nog geen langetermijnresultaten beschreven van deze component in de jonge patiënt. In Hoofdstuk 6 beschrijven wij de klinische en radiologische middellangetermijnresultaten van de gecementeerde polyethyleen Contemporary cup in primaire THP in patiënten jonger dan 50. Bij 126 patiënten die in de periode 1999-2006 jonger dan 50 waren, werden 152 polyethyleen Contemporary cups gebruikt, met en zonder acetabulaire IBG. Na een gemiddelde follow-up-duur van 7.6 jaar (0.9-12.0 jaar) was één patiënt lost-to-follow- up. Alle klinische vragenlijstscores (HHS-, OHS- en Visueel Analoge Schaal-scores voor pijn in rust, pijn gedurende activiteit en de score voor tevredenheid) waren verbeterd. De radiologische follow-up was compleet voor 146 implantaten en liet een acht jaars overleving voor het eindpunt radiologische loslating zien van 93.1% (95% CI: 86.2-96.6). Acht acetabulaire componenten werden vervangen. Vijf vanwege aseptische loslating na 10 1.1, 2.5, 3.1, 5.0 en 6.0 jaar na operatie. Eén Contemporary hooded cup werd gereviseerd vanwege recidiverende luxaties, 3.5 jaar na de operatie, en één cup liet posttraumatische loslating zien na 4.3 jaar. Eén hooded cup zonder IBG werd gereviseerd als onderdeel van een volledige revisie-THP in verband met septische loslating na 0.9 jaar. Dit resulteerde in een overleving van de cups met als eindpunt revisie om welke reden dan ook van 94.4%

185 Cemented total hip arthroplasty and impaction bone grafting in young patients

(95% CI: 89.2-97.2) na 8 jaar, terwijl de overleving van cups met als eindpunt revisie voor aseptische loslating 96.4% (95% CI: 91.6-98.5) was. Het hoge luxatie percentage van 5.6% dat werd vastgesteld in de groep patiënten die behandeld was met een Contemporary hooded cup, resulteerde in het Radboudumc in een stop van het gebruik van dit type cup en een switch naar het type flanged cup. De relatief grote verhoging van de posterieure rand van de Contemporary hooded cup lijkt te functioneren als een bron van ‘impingement’ waardoor er juist meer luxaties optreden. Dat is opvallend, aangezien dit type cup juist was ontworpen met een verhoogde posterieure rand om de luxatie-aantallen te verlagen.

6. Wat is er in de literatuur bekend over de overleving van primaire heupprothesen en de overleving van de daaropvolgende revisie-prothesen in datzelfde cohort van patiënten onder de 50 jaar.

Hoofdstuk 7 toont een systematische review van de beschikbare literatuur met betrekking tot cohorten waarbij in dezelfde slag een beschrijving plaatsvindt van zowel de overleving van de primaire implantaten na een gemiddelde follow-up-duur van 10 jaar als de resultaten van de daaropvolgende revisie-operaties. Dit is een belangrijk onderwerp aangezien het voor de jonge patiënt erg belangrijk is om de invloed van het type primair implantaat en fixatie op de daaropvolgende revisie te weten. Vergeleken met de oudere patiënt heeft de jonge patiënt door zijn langere levensverwachting ten tijde van de operatie een hogere kans op het moeten ondergaan van een revisie operatie tijdens zijn leven. Tot dusver worden in publicaties betreffende de revisie-THP-operaties bij jonge patiënten vaak geselecteerde cohorten van revisie-patiënten binnen een beperkt tijdsbestek weergegeven. Daarnaast worden de resultaten van deze revisie-operaties vervolgens vaak weergegeven zonder gedetailleerde informatie over de patiënt zelf en de primaire THP. Dit kan leiden tot het selectief rapporteren van uitkomsten wat kan resulteren in incomplete informatie 10 over het succes van de primaire THP in de jonge patiënt en in inaccurate beslissingen. Daarom zou men in het geval van het rapporteren van uitkomsten van revisie-THP ook de uitkomsten van de primaire THP en de patiëntkarakteristieken moeten meenemen. We voerden een literatuur onderzoek uit om te zien in hoeverre revisie-uitkomsten op deze manier reeds gerapporteerd worden. Medline, Embase en de Cochrane Library werden daarom tot en met 13 april 2016 doorzocht op studies welke zowel de overleving

186 CHAPTER 10

Nederlandse samenvatting en algemene discussie van de primaire THP in de jonge patiënt als de overleving van daaropvolgende revisie THP rapporteerden. Studies waren geschikt indien zij patiënten includeerden die hun primaire THP op een leeftijd jonger dan 50 jaar hadden ontvangen en daarbij zowel de cup- en steel-overleving van de primaire en de daaropvolgende revisie binnen hetzelfde cohort rapporteerden. Een Kaplan-Meier analyse of een competing risk analyse voor het eindpunt revisie om welke reden dan ook moest beschreven zijn voor zowel de primaire THP na een gemiddelde follow-up-duur van 10 jaar als voor de daaropvolgende revisies in hetzelfde cohort. Twee onafhankelijke reviewers beoordeelden of de studie voldeed aan de genoemde criteria en beoordeelden de kwaliteit van de studies. Er werden 4.799 unieke resultaten gevonden waarvan er 43 geschikt leken, maar waarvan er slechts één aan alle inclusiecriteria voldeed. Concluderend is er een duidelijk gebrek aan onderbouwend bewijs betreffende de uitkomsten van revisie-THP na primaire THP in de jonge patiënt. Met het toenemende aantal jonge patiënten dat een heupprothese ontvangt, kunnen we in de toekomst grote aantallen revisies verwachten waarbij mogelijk niet de optimale primaire en revisie-behandeling is uitgevoerd met als gevolg dat er voor een eventuele (re-)revisie geen goede reconstructieve mogelijkheden voor deze patiënten zijn. Dat zou een voor de maatschappij onwenselijke toename in medische zorg en kosten betekenen.

7. Kunnen we IBG veilig toepassen in patiënten zonder een acetabulair defect om op deze manier de langetermijnuitkomsten te verbeteren?

Deze laatste onderzoeksvraag wordt beschreven in Hoofdstuk 8 en richt zich op een nieuw concept om de cup-overleving in patiënten onder 50 jaar te verbeteren. Ten opzichte van de steel is de cup nog steeds de zwakke schakel binnen de THP. Gebaseerd op de goede klinische resultaten van IBG in jongere patiënten over de afgelopen jaren, hebben we IBG nu ook toegepast in jongere patiënten die geen acetabulair botdefect hadden. We denken dat door het toevoegen van IBG in primair gecementeerde THP’s 10 de botcement-interdigitatie verbetert en daarmee ook de cup-overleving verlengd wordt, zelfs in de afwezigheid van het acetabulaire botdefect. Ook wordt de botconfiguratie van het acetabulum hersteld. Echter, dit is in dit geval niet het primaire doel van de procedure. Het doel van de studie beschreven in hoofdstuk 8, was het onderzoeken of er een verschil is in het aantal vroege revisie-operaties en andere vroege complicaties tussen

187 Cemented total hip arthroplasty and impaction bone grafting in young patients

patiënten jonger dan 50 jaar die een primair gecementeerde THP met of zonder IBG kregen in de afwezigheid van een acetabulair botdefect. Daartoe werden twee cohorten met elkaar vergeleken: heupen zonder een acetabular defect welke een gecementeerde cup zonder IBG ontvingen (non-IBG groep, n = 30) in de periode 1-1-2006 tot 2008 en heupen zonder een acetabular defect welke een gecementeerde cup ontvingen nadat er eerst een laag botsnippers werd geïmpacteerd (IBG groep, n = 29) in de periode 1-1-2008 tot 2010. De in totaal 59 operaties werden door 3 verschillende orthopedisch chirurgen uitgevoerd en in alle operaties werd de posterolaterale benadering gebruikt. Om het cementeren te optimaliseren (non-IBG groep) en om de vascularisatie van de graft (IBG groep) te bevorderen werd het acetabulaire botbed eerst voorbereid door er multipele 2 mm boorgaatjes in te maken. In de non-IBG groep werd na het spoelen en drogen van het botbed direct gecementeerd op het acetabulaire botoppervlak. In de IBG groep, werd een autograft van de oude heupkop van de patiënt, dan wel een allograft, dan wel een combinatie van beiden verwerkt tot botchips van 7-10 mm groot. Deze werden geïmpacteerd met een metalen impactor en een hamer. Het vacuüm gemixte cement werd onder druk direct of het bodbed dan wel op de geïmpacteerde grafts aangebracht. Vervolgens werd de cup werd geplaatst. Patiënten die een graft hadden ontvangen mochten de eerste 6 weken 10% belast mobiliseren gevolgd door 6 weken 50% belast mobiliseren. De twee cohorten verschilden voor wat betreft hun patiënt karakteristieken niet significant van elkaar. De gemiddelde leeftijd van de 59 patiënten gezamenlijk was 36.2 (15.3-49.4) jaar. Ten tijde van review was één patiënt lost to follow-up nadat deze patiënt was geëmigreerd. Geen van de patiënten was overleden en iedereen had een minimale follow-up van 2 jaar. Radiologische en klinische parameters werden beoordeeld. Kaplan-Meier survival analyses werden gebruikt om de overleving van de componenten te bepalen. Er traden geen intra-operatieve complicaties gerelateerd aan plaatsing van de cups op. De operatieduur nam in de IBG –groep met gemiddeld 8 minuten toe. Voor de non-IB groep was de overleving na 2 jaar voor het eindpunt revisie om welke reden dan 10 ook 96.7% (95% CI: 78.6-99.5) en voor de IBG groep was dit 93.1% (95% CI: 75.1-98.2). Drie cups werden vervangen vanwege recidiverende luxaties (één in de non-IBG groep en twee in de IBG groep). Bij alle drie de patiënten was er sprake van artrose op jonge leeftijd na een eerder trauma van het bekken. Eén revisie (IBG groep) werd uitgevoerd in verband met infectie. Voor het eindpunt revisie voor aseptische loslating werd in beide groepen een overleving van 100% na 2 jaar gezien. Van de 55 cups die niet gereviseerd

188 CHAPTER 10

Nederlandse samenvatting en algemene discussie waren, liet 1 cup in de non-IBG groep radiologische loslating zien. Verder was er één cup in de non-IBG groep die een non-progressieve radiolucente lijn liet zien in zone 1 van het acetabulum. In de IBG-groep lieten 2 cups progressieve radiolucente lijnen zien, ieder in één acetabulaire zone. Deze nieuwe toepassing van IBG in jonge patiënten zonder acetabulair botdefect maar met uitgebreide (secundaire) coxartrose kan een aantrekkelijke oplossing zijn. Intensieve follow-up van deze groep is nodig om zowel de langetermijnresultaten te beoordelen als de technische voordelen ten tijde van eventuele revisie-operaties te kunnen bepalen. Daarnaast zijn er studies met grote aantallen patiënten nodig. Prospectieve gerandomiseerde studies betreffende dit onderwerp kunnen de data leveren om het antwoord op de volgende vraag te geven: “Levert deze techniek op lange termijn daadwerkelijk voordeel op voor deze specifieke groep patiënten?”

ALGEMENE DISCUSSIE

Wereldwijd worden er steeds meer THP’s in jonge patiënten geplaatst. Terwijl wereldwijd het aantal gecementeerde THP’s in de jonge patiënten afneemt, neemt het aantal ongecementeerde THP’s in deze groep juist toe. Hoge revisie-aantallen werden gezien voor ongecementeerde metaal-op-metaal articulaties, maar voor metaal-op- polyethyleen articulaties zijn de 10-jaars-overlevingsresultaten voor gecementeerde en ongecementeerde THP’s vrijwel gelijk aan elkaar. Wat er na die eerste 10 jaar gebeurt is veel minder duidelijk. En informatie rondom technisch uitdagendere casuïstiek en rondom onvermijdelijke revisie-operaties is in verhouding summier. In dit proefschrift worden de langetermijnresultaten van de gecementeerde THP en IBG na deze eerste 10-jaar-follow-up-duur onderzocht. De hele jonge patiënten (jonger dan 30 jaar) die een gecementeerde THP ontvingen en waarbij in geval van een acetabulair botdefect ook IBG werd toegepast, lieten een 10- en 15-jaars overleving zien 10 van respectievelijk 90% en 82% voor het eindpunt revisie voor aseptische loslating. Deze overleving is helaas nog wel lager dan de algemene overlevingspercentages voor zowel de gecementeerde als de ongecementeerde THP die worden gevonden in veel landelijke heupregisters waarin ook oudere patiënten zijn geïncludeerd. Ook de Orthopaedic Data Evaluation Panel (ODEP)-criteria verwachten een langere overlevingsduur van zowel

189 Cemented total hip arthroplasty and impaction bone grafting in young patients

ongecementeerde als gecementeerde implantaten. Maar de resultaten zijn vergelijkbaar met die van de beschikbare data van jongere patiënten. Er is echter nog een aspect waar men rekening mee dient te houden in het geval van een jonge patiënt: de reviseerbaarheid van het implantaat. De gecementeerde THP laat acceptabele langetermijn-overlevingsresultaten zien bij jonge patiënten met technisch uitdagende reconstructies van het aangedane heupgewricht dat onderhevig is aan eindstadium-artrose. Het is voor orthopedisch chirurgen daarom belangrijk om ook een goed gecementeerde prothese met behulp van de derde graads cementeringstechniek te kunnen uitvoeren. Het zou jammer zijn wanneer in de orthopedische wereld een verlies van de technische vaardigheden die nodig zijn voor het uitvoeren van een adequaat gecementeerde THP, zou optreden. Dit proefschrift laat ook zien dat een revisie-operatie van gecementeerde componenten goed uitgevoerd kan worden met opnieuw gecementeerde componenten, zelfs in deze soms technisch zeer uitdagende reconstructies zoals in dit proefschrift geïncludeerd. Naast de fixatie-techniek speelt ook de aanwezige botconfiguratie een belangrijke rol in het kunnen reviseren van een prothese. Er dient aandacht te zijn voor het herstellen van de botconfiguratie. Jonge patiënten overleven vaak hun primaire prothese. Het botbed dat overblijft na het verwijderen van de gefaalde primaire prothese, kan van invloed zijn op de techniek en overlevingsresultaten van de revisie-procedure. In dergelijke gevallen is acetabulaire IBG een aantrekkelijke biologische manier om een eventueel aanwezig botdefect reeds ten tijde van plaatsing van het primaire implantaat te herstellen. Om de optimale resultaten te krijgen dient men goed te letten op de juiste keuze van de maat botsnippers (8-12 mm) en het correct uitvoeren van het impacteren van deze botsnippers. Kleine variaties binnen deze originele techniek kunnen tot inferieure klinische resultaten leiden. In tegenstelling tot technieken die grote metalen cups, metalen wigjes of grote cages gebruiken, kan IBG worden gecombineerd met dunne metalen meshes in ongeveer alle typen acetabulaire defecten. De enige 10 uitzondering zijn de hele grote defecten. Hiervan wordt in de literatuur beschreven dat de uitkomst van IBG minder succesvol is. Andere technieken die in het geval van een botdefect ten tijde van plaatsing van de primaire THP ook gebruikt worden - zoals bulk grafts -, zijn wel beschreven, maar er is nog weinig bekend over de uitkomsten van revisie-prothesen waarbij opnieuw een dergelijke bulk graft gebruikt wordt. Tot dusver is het onbekend of deze reconstructies met een dergelijke bulk graft daadwerkelijk meer bot produceren en dus een volgende revisie-operatie vergemakkelijken.

190 CHAPTER 10

Nederlandse samenvatting en algemene discussie

Door de botvoorraad steeds weer te herstellen in het geval van zowel een primaire als een revisie-operatie, proberen we steeds de botcement-interface te optimaliseren, maar creëren we ook een optimale basis voor de verwachte toekomstige revisies. In onze primaire en revisie-reconstructies met een gecementeerde THP en IBG in patiënten jonger dan 50, zagen we na 30 jaar 56% overleving voor het eindpunt revisie voor aseptische loslating en 40% overleving voor het eindpunt revisie om welke reden dan ook, wat unieke resultaten zijn. Dit proefschrift laat zien dat revisie-operaties van gecementeerde THP’s met of zonder IBG, dus beide uitgevoerd kunnen worden met opnieuw een gecementeerde prothese en IBG. Zelfs in de afwezigheid van een acetabulair botdefect kan IBG worden toegevoegd aan het acetabulaire botbed om zo de cement-botfixatie te bevorderen. Onze studie liet geen toegenomen risico op vroege complicaties zien. Ook werd er geen vroege aseptische loslating gezien op de röntgenfoto’s. Dit zijn de eerste resultaten betreffende IBG en een gecementeerde THP in jonge patiënten zonder acetabulair botdefect. Momenteel worden van een veel grotere groep patiënten de data verzameld en geanalyseerd. Om daadwerkelijk vast te stellen wat er met de grafts in de patiënten is gebeurd, zijn aanvullend histologische studies nodig aangezien radiologische beoordeling hiervan niet betrouwbaar genoeg is. Het in dit proefschrift beschreven onderzoek is tevens gericht op een evaluatie van radiologische kenmerken die kunnen wijzen op radiologische loslating zoals radiolucente lijnen en osteolyse. In de literatuur wordt het optreden van radiolucente lijnen en osteolyse met zeer wisselende incidentie beschreven, wat illustreert hoe moeilijk het kan zijn om radiologische resultaten te vergelijken. De verschillende in de literatuur beschreven incidenties kunnen ook samenhangen met verschillende cup-designs, het gebruik van andere criteria voor het beschrijven van radiologische kenmerken of met het grote aantal ontbrekende röntgenfoto’s ten tijde van follow-up. Al onze studies hebben geen of lage aantallen patiënten die lost-to-follow-up waren en de criteria voor het beoordelen van röntgenfoto’s zijn door de jaren heen altijd dezelfde gebleven. We beseffen dat we in sommige studies vrij hoge aantallen radiolucente lijnen en osteolyse beschrijven in 10 vergelijking met de aantallen beschreven in andere studies. Het is echter opvallend dat in onze cohorten deze radiolucente lijnen vaak stabiel blijven en er geen progressieve afname van de survivalcurven te zien is voor zowel de femorale als acetabulaire component na 10 jaar als gevolg van aseptische loslating. Betreffende de Exeter steel zagen we een wat hoger aantal radiolucente lijnen rondom de femorale component dan het percentage

191 Cemented total hip arthroplasty and impaction bone grafting in young patients

radiolucente lijnen (9.8%) dat door Lewthwaite et al werd beschreven in hun cohort van Exeter Universal stelen in jonge patiënten. Vaak waren de lijnen in onze groep aanwezig in slechts één of twee Gruen zones en resulteerde enige uitbreiding van radiolucentie rondom de steel niet in volledige radiologische loslating. Er werd geen relatie gevonden met het optreden van polyethyleen slijtage van de cup. Dergelijke observaties dienen in de toekomst goed vervolgd te worden om het eventueel alsnog optreden van radiologische loslating te kunnen evalueren. Een andere belangrijke les die geleerd werd uit één van de studies is dat het design van de acetabulaire component het risico op luxatie van de THP enorm kan beïnvloeden. Deze observatie zorgde ervoor dat we stopten met het implanteren van de Contemporary Hooded cups in onze patiënten. Dergelijke observaties kunnen alleen worden gedaan middels het adequaat vervolgen van patiënten en hun implantaten. Het illustreert hoe belangrijk de informatie is die men uit cohort studies kan verkrijgen. Het bevestigt, net als de problemen die we zagen rondom de resurfacing heupprothese, dat nieuw geïntroduceerde implantaten aandachtig dienen te worden geobserveerd in de vroege fase maar ook moeten worden beoordeeld op hun langetermijnresultaten en mogelijkheden tot revisie. Al met al resulteert een gecementeerde THP in combinatie met acetabulaire IBG in een biologische reconstructie. In het geval van falen is op lange termijn ook weer revisie mogelijk middels opnieuw een gecementeerde cup en IBG.

CONCLUSIES AAN AANBEVELINGEN

Dit proefschrift laat zien dat acceptabele langetermijnresultaten van de gecementeerde THP in jonge patiënten verwacht kunnen worden indien deze middels de adequate derde generatie cementeringstechniek worden verricht en, indien nodig, IBG wordt 10 toegepast. Gebaseerd op de resultaten in patiënten met acetabulaire botdefecten menen we dat er een indicatie is voor het gebruik van IBG, zelfs wanneer er geen botdefect aanwezig is. Het kan dan de bot-cement-interface verbeteren. In de eerste 2 jaar follow- up werden er geen extra complicaties waargenomen welke veroorzaakt zouden kunnen worden door het toevoegen van IBG aan de standaardprocedure in afwezigheid van een acetabulair botdefect. Er is vervolg onderzoek nodig om de verwachte toename in

192 CHAPTER 10

Nederlandse samenvatting en algemene discussie langetermijnoverleving van deze fixatie in jonge patiënten zonder acetabulair defect te bewijzen. Ook is het interessant om te weten of hierdoor de patiënttevredenheid kan verbeteren. Als laatste werd in dit proefschrift een eerste stap gezet in een nieuwe richting van rapporteren van uitkomsten. Meer dan bij oudere patiënten is het in het geval van jonge patiënten belangrijk om de uitkomst van de primaire prothese te koppelen aan de uitkomst van de daaropvolgende revisie-prothese aangezien deze patiënten hun prothese vaak zullen overleven. In toekomstig onderzoek zal daarom ook meer de nadruk moeten liggen op het combineren van deze resultaten met het identificeren van factoren die op een positieve dan wel negatieve manier de resultaten van revisiechirurgie kunnen beïnvloeden. We moeten blijven proberen hier zo goed mogelijk onderbouwd bewijs voor te krijgen. Op die manier kunnen we de jonge patiënten met coxartrose zo accuraat mogelijk voorzien van informatie alvorens hij of zij een THP ontvangt.

In de toekomst moeten we ons richten op: • de langetermijnresultaten van de acetabulaire component in combinatie met impaction bone grafting in het geval van afwezigheid van een acetabulair botdefect ten tijde van primaire chirurgie; • ‘patient reported outcome measurements’ (PROMs) inclusief de tevredenheid op lange termijn en het activiteitenniveau van patiënten die impaction bone grafting ontvangen zonder acetabulair defect; • kosten-effectiviteitsanalyse van het toevoegen van impaction bone grafting aan de totale heupprothese procedure in jonge patiënten zonder een acetabulair defect; • de reviseerbaarheid van primaire componenten en de invloed van de aanwezige botconfiguratie ten tijde van de revisiechirurgie.

10

193

Dankwoord

List of publications, presentations and posters

Curriculum Vitae Cemented total hip arthroplasty and impaction bone grafting in young patients

DANKWOORD

In de afgelopen jaren hebben veel mensen een bijdrage geleverd aan de totstandkoming van dit proefschrift. Daarvoor uiteraard veel dank! Een aantal personen wil ik graag in het bijzonder noemen.

Prof. dr. R.P.H. Veth (promotor), beste René, nu is het echt zover: je laatste promovenda is klaar. Net na de ‘deadline’, maar dat mag de pret niet drukken. Het was natuurlijk ook wel heel bijzonder voor mij om zo vlak voor je pensioen nog te mogen starten als jouw promovenda. Dank voor de vele wijze lessen rondom de totstandkoming van dit proefschrift en mijn keuzes binnen de orthopedie.

Dr. B.W. Schreurs (co-promotor), beste Wim, na mijn opleiding geneeskunde vroeg ik uit interesse of ik bij jou onderzoekster kon worden. Je bood me daarbij de prachtige kans om promotieonderzoek te gaan doen. Jouw altijd aanwezige energie en enthousiasme dwongen grote bewondering bij me af. Je bent zeer betrokken geweest bij mijn werk en bij alle patiënten die in dit onderzoek zijn meegenomen. Daarnaast waardeer ik je niet aflatende interesse in het reilen en zeilen van de ander. Bedankt voor al je tijd, energie, scherpe commentaren, luisterend oor en vooral ook voor je humor gedurende de afgelopen jaren.

Dr. J.W.M. Gardeniers (co-promotor), beste Jean, mede dankzij jouw kundig handelen en zeer gedetailleerde operatieverslagen is er een mooie database opgebouwd. Tevens stond je altijd paraat om de artikelen te voorzien van commentaar; de laatste jaren vanuit Zuid-Afrika waar soms de bliksem wat roet in de snelle verbindingen gooide. “TIA!” (“This is Africa, man!”)

Leden van de manuscriptcommissie, geachte prof. dr. W.B. van den Berg, prof. dr. S.J. Bergé, prof. dr. B.J. van Royen, hartelijk dank voor de beoordeling van het manuscript.

Wim Rijnen. Als opvolger van Jean Gardeniers is er nu nóg een enthousiaste en oprecht geïnteresseerde Wim, orthopedisch chirurg in het Radboudumc. Ook bij jou zijn de jonge heuppatiënten in goede handen. Dank voor het feedback geven op mijn manuscripten.

196 Dankwoord

Jan Hendriks. Dank voor alle hulp en het sparren over de uitvoering van analyses. Altijd werd een geduldig luisterend oor geboden en een goede raad gegeven.

Gerjon Hannink. Met name het laatste jaar hebben we veel samen gewerkt om de laatste analyses af te ronden. Ook fijn dat je altijd klaar stond om te sparren over het commentaar van reviewers. Dank voor je hulp.

Beste Jaap Brunnekreef, Martin Pouw, Joost van Middendorp, Martijn te Stroet en Eelco Bronsema, vele gebouwen zijn de afgelopen jaren door de onderzoekers van orthopedie ‘versleten’ en staan ondertussen niet meer rechtop. Het was top om met jullie samen te werken.

Daniël de Kam en Vincent Busch. Dank voor het leggen van de basis voor een gedeelte van dit proefschrift.

Ena Colo en Carla Timmer. Het was een eer om jullie te begeleiden bij de eerste stappen van jullie onderzoek binnen de orthopedie. De samenwerking heeft geleid tot mooie projecten waaronder ook het geslaagde symposium dat we mede voor jonge heuppatiënten hebben georganiseerd. Ondertussen genieten jullie ieder met volle teugen van dit vakgebied. Leuk dat we naast de koffiebar in het ziekenhuis ook vaker een restaurant of de Nijmeegse Vierdaagse feesten bezochten. Dank voor de fijne samenwerking en gezelligheid de afgelopen jaren.

Willemijn en Nadja. Het was leuk om jullie te mogen begeleiden tijdens jullie onderzoeksstage.

Stafleden ROGOO en A(N)IOS ROGOO. Hartelijk dank voor de samenwerking in de afgelopen jaren. In het bijzonder mijn dank aan jou Bram. Als ANIOS duo konden we rekenen op elkaar en naast werken werd er vooral ook veel samen gelachen.

Alle patiënten. Zonder uw medewerking zou dit onderzoek nooit gelukt zijn. Hopelijk draagt dit en ander onderzoek bij aan uw welzijn.

197 Cemented total hip arthroplasty and impaction bone grafting in young patients

Medewerkers polikliniek, secretariaat en klinisch scoringstation orthopedie Radboudumc. Dank voor jullie inzet, het regelen van afspraken en verzamelen van data.

Miranda Dood. Hartelijk dank voor het omzetten van mijn manuscript naar dit boekje en het snelle schakelen daarbij.

Marieke en Sanne, lieve oud-huisgenootjes, lieve vriendinnen, al ver voor dit promotietraject leerden we elkaar kennen in ons oude studentenhuis. Sindsdien hebben we veel samen gedaan. Dat we altijd bij elkaar terecht konden en kunnen waardeer ik enorm. In de afgelopen jaren heb ik veel aan jullie steun gehad. Ik geniet altijd van de gezelligheid met jullie en kijk uit naar meer tijd samen!

Yvonne en Sanne. Wat fijn dat jullie mijn paranimfen willen zijn! Samen begonnen aan geneeskunde; en tijdens een van de vele gezamenlijke avonden in een gekke bui op de foto met een poster van een heupgewricht. Dat kan geen toeval zijn! En dus sluiten jullie samen met mij dit hoofdstuk af. Op naar wat meer tijd om elkaar te bezoeken nu we niet meer samen in Nijmegen wonen.

Marlous, Paulien, Pia en Renée. Geneeskunde dames Nijmegen, door de jaren heen veel samen beleefd. In Nijmegen maar ook buiten de landsgrenzen zoals in Dusseldorf of zelfs in Zuid-Afrika. Dank voor jullie altijd aanwezige interesse.

Schouten en Prins, oftewel Helga en Wiesje, oud co-genoten en lieve vriendinnen. Jullie zagen tijdens onze studie hoe ik helemaal blij werd van orthopedie. Vol interesse hebben jullie mijn werkzaamheden gevolgd. Daarnaast waren er natuurlijk onze eigen belangrijke onderzoekslijnen zoals de invloed van Baileys op het reactievermogen tijdens een spelletje ‘Set’. Al zijn we het, geloof ik, nooit eens geworden over de interpretatie van de resultaten.

Charlotte. Tijdens onderzoekswerk bij de afdeling palliatieve zorg leerden we elkaar als mede-studenten beter kennen. Sindsdien is onze vriendschap alleen maar sterker geworden. Dank voor de vele morele steun de afgelopen jaren.

198 Dankwoord

Rianne. Vanaf de middelbare school al vriendinnen, om vervolgens samen geneeskunde te gaan studeren, alleen jij in Rotterdam en ik in Nijmegen. Super om met jou en je familie ‘vastelaovend’ te vieren, altijd garantie voor lol en ontspanning. Tegelijkertijd altijd fijn om met jou in vaktermen te kunnen sparren.

Jill. Soms gaan onze beide achtbanen zo hard dat het amper te volgen was voor elkaar, maar gelukkig kruisen die elkaar altijd weer: vanaf de brugklas al weten we elkaar steeds weer te vinden. Voor een goed feestje of een dikke knuffel, even een belletje tot onverwachts voor de deur staan. De momenten van bijpraten zijn dan ook steevast goed!

De Limburgse sushi-clan! Deze keer toch echt locatie Nijmegen!

Oom Jan. Dank voor het meelezen van mijn samenvatting en voor het bruikbaar commentaar daarbij. Leuk ook om te sparren over stellingen en de anekdotes rondom je eigen promotie van destijds te horen.

Oom Jean en tante Elly. Altijd mag ik jullie vragen om hulp. Nooit vraag ik te veel. En dat is en blijft heel erg fijn!

Marianne, lieve schoonmoeder, het is fijn om je nu te kunnen laten zien waar ik vaak in de weekenden mee bezig was en waardoor ik minder tijd had voor gezellige familie- afspraken. Fijn dat je altijd voor Hub en mij klaarstaat!

John en Rebecca. Ik wens jullie veel plezier met het lezen van mijn ‘boekje’. Wellicht wel even een ander achtergrond muziekje opzetten.

Lieve pap, ik weet dat je trots op me bent. Jammer dat je dat zelf niet meer kunt zeggen.

Lieve mam, altijd sta je voor me klaar, wat er ook aan de hand is; altijd ben je er voor mij. Mede daardoor heb ik dit proefschrift kunnen afronden. Dankjewel, ik hou van je!

Lieve Hub, je hebt deze speciale plek in dit boekje zo ongelooflijk hard verdiend met al jouw geduld en steun naar mij toe. Ik was net begonnen als ANIOS-orthopedie en vanaf

199 Cemented total hip arthroplasty and impaction bone grafting in young patients

dat moment heb je alles met mij gedeeld. De afgelopen jaren ben je er steeds voor mij geweest, op fijne maar ook op moeilijke momenten. Daarvoor ben ik je zeer dankbaar. Gelukkig vergeten we nooit tussendoor te genieten en te lachen. Fijn dat je me hebt geholpen dit boekje af te ronden. Wat een bijzonder ‘team’ zijn wij toch!

200 Dankwoord

201 Cemented total hip arthroplasty and impaction bone grafting in young patients

LIST OF PUBLICATIONS

1. Schmitz MWJL, Bronsema E, De Kam DCJ, Gardeniers JWM, Veth RPH, Schreurs BW. Results of the cemented Exeter femoral component in patients under 40 years of age. An update at 10 to 20 years follow-up. Bone and Joint Journal 2017 feb;99-B(2):192-198.

2. Schmitz MWJL, Hannink G, Gardeniers JWM, Verdonschot N, Slooff TJJH, Schreurs BW. Acetabular reconstructions with impaction bone-grafting and a cemented cup in patients younger than fifty years old. A concise follow-up, at twenty-seven to thirty-five years, of a previous report. Accepted for publication in the Journal of Bone and Joint Surgery. In press.

3. Van Westendorp S, Rijnen WHC, Buyne OR, Schmitz MWJL. An intraperitoneal mesh for transacetabular hernia of the small bowel during total hip replacement - a case report. NTvO Vol 23, Nr 4, December 2016.

4. Schmitz MWJL, Busch VJJF, Gardeniers JWM, Hendriks JCM, Veth RPH, Schreurs BW. Long-term results of cemented total hip arthroplasty in patients younger than 30 years and the outcome of subsequent revisions. BMC Musculoskeletal Disorders 2013; Jan 22;14:37.

5. Schmitz MWJL, Timmer C, Rijnen WHC, Gardeniers JWM, Schreurs BW. Clinical and radiological outcome of the cemented Contemporary acetabular component in patients < 50 years of age. Bone Joint J 2013;95-B:1617–25.

6. Schmitz MWJL, Veth RPH, Schreurs BW. Hip resurfacing in patients under 55 years of age. Ned Tijdschr Geneesknd 2011;155:A3186.

7. Schmitz MWJL, Van Grinsven S, Rijnberg WJ, Van Loon CJM. Frequente schroefbreuk na gebruik Numelockfixatiesysteem bij openwig-tibiakoposteomie. NTVO Juni 2010, 17e jaargang, nr. 2.

202 List of publications, presentations and posters

8. Schmitz MWJL, De Waal Malefijt MC, Van Heereveld HAEM. Resection arthroplasty for luxation of the manubrio-sternal joint in rheumatoid arthritis – a case report. Acta Orthop. 2010 Jun;81(3):405-6.

203 Cemented total hip arthroplasty and impaction bone grafting in young patients

PRESENTATIONS AND POSTERS

1. American Academey of Orthopaedic Surgeons annual meeting 2017. San Diego: Schmitz MWJL, Hannink G, Gardeniers JWM, Colo E, Verdonschot N, Slooff TJJH, Schreurs. BW. 25- Year survival of acetabular reconstructions with impaction bone grafting and a cemented cup in young patients. (Poster)

2. European Hip Society 12th Congress 2016, München: Schmitz MWJL, Hannink G, Gardeniers JWM, Slooff TJJH, Schreurs BW. A minimum 25-Year survival of acetabular reconstructions with impaction bone-grafting and a cemented cup in patients younger than fifty years old

3. 16th Congres of the European Federation of National Assocations of Orthopaedics and Traumatology 2015, Praag: Schmitz MWJL, Bronsema E, De Kam DCJ, Gardeniers JWM, Schreurs BW. Results of the cemented Exeter Universal femoral component in patients under 40 years at a minimal follow up of ten years.

4. European Hip Society 11th Congress 2014, Stockholm: Schmitz MWJL, Wolf N, Brunnekreef JJJ, Faber MJ, Schreurs BW. Postoperative total hip arthroplasty patients and their need for online information and online support groups.

5. Vereniging Orthopaedisch Chirugische Assistenten congres 2012, Rotterdam: Total hip arthroplasty in the young patient. Schmitz MWJL, Schreurs BW.

6. Najaarsvergadering Nederlandse Orthopaedische Vereniging 2012, Veldhoven: Schmitz MWJL, Busch VJJF, Gardeniers JWM, Hendriks JCM, Veth RPH, Schreurs BW. Succesvolle totale heupprothesen in de jonge patiënt: een kwestie van kunnen reviseren.

7. European Hip Society 10th Congres 2012, Milaan: Schmitz MWJL, Rijnen WHC, Gardeniers JWM, de Kam DCJ, Schreurs BW. Low incidence of greater trochanter fractures after cemented total hip arthroplasty in young patients.

204 List of publications, presentations and posters

8. European Hip Society 10th Congres 2012, Milaan: Schmitz MWJL, Colo E, Rijnen WHC, Gardeniers JWM, Schreurs B. Impaction bone grafting in primary total hip arthroplasty in absence of acetabular defects: the results after 2 years follow-up. (Poster)

9. American Academy of Orthopaedic Surgeons annual meeting 2012, San Francisco: Schmitz MWJL, Busch VJJF, Gardeniers JWM, Hendriks JCM, Veth RPH, Schreurs BW. Outcome at fifteen years for cemented total hip arthroplasty and revisions in patients under 30 years. A new approach in reporting long-term follow-up. (Poster)

10. ISTA 24th Annual Congress, Brugge: Schmitz MWJL, Busch VJJF, Gardeniers JWM, Hendriks JCM, Veth RPH, Schreurs BW. Outcome at fifteen years for cemented total hip arthroplasty in patients under 30 years and the outcome of their revisions.

205 Cemented total hip arthroplasty and impaction bone grafting in young patients

206 Curriculum Vitae

CURRICULUM VITAE

Marloes Schmitz werd geboren op 31 augustus 1985 te Venlo. In 2003 behaalde zij haar tweetalig VWO diploma aan het Den Hulster College in Venlo. Ze ging vervolgens geneeskunde studeren aan de Radboud Universiteit in Nijmegen. Voor de start van haar coschappen heeft ze vrijwilligerswerk verricht in het orthopedisch kinderziekenhuis ‘Maitland Cottage Home’ in Kaapstad, Zuid-Afrika. Tijdens haar coschappen groeide de interesse voor de Orthopedie. Het senior coschap volgde zij daarom in de Sint Maartenskliniek te Nijmegen. Tijdens de coschappen voerde zij tevens haar eerste wetenschappelijk onderzoek binnen de Orthopedie uit in het Rijnstate Ziekenhuis te Arnhem. Voor haar wetenschappelijke stage vertrok zij naar Brisbane (Australië) alwaar zij onderzoek verrichte aan de Queensland University of Technology. Vanuit Nederland was haar begeleider Dr. B.W. Schreurs. In 2010 behaalde zij haar artsexamen en startte zij met promotie onderzoek bij de afdeling Orthopedie van het Radboudumc, wederom onder begeleiding van Dr. B.W. Schreurs. Na haar onderzoek in de eerste maanden te hebben opgestart heeft zij een half jaar als arts-assistent Orthopedie niet- in- opleiding gewerkt. Nadat ze vervolgens was aangenomen voor de opleiding tot orthopedisch chirurg heeft ze nog ruim een jaar als promovenda gewerkt. In 2013 startte zij met de vooropleiding Heelkunde in het Rijnstate te Arnhem (opleider M.M.P.J. Reijnen). Per 1 juli 2014 startte zij met het orthopedie- gedeelte van haar opleiding in het Radboudumc (opleider M.C. De Waal Malefijt). Rond het einde van het derde jaar van haar opleiding heeft zij na een goede afweging besloten op een andere manier met orthopedie verder te willen en haar opleiding tot orthopedisch chirurg beëindigd. Na enkele maanden in het Radboudumc aan haar onderzoek te hebben gewerkt is ze per 1 september 2016 werkzaam als research coördinator bij de Nederlandse Orthopaedische Vereniging. Daarnaast is zij in het Radboudumc werkzaam als onderwijsondersteuner bij de afdeling Orthopedie.

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CEMENTED TOTAL HIP ARTHROPLASTY AND IMPACTION BONE GRAFTING IN YOUNG PATIENTS - - PATIENTS YOUNG IN GRAFTING BONE IMPACTION AND ARTHROPLASTY TOTALHIP CEMENTED MARLOES W.J.L. SCHMITZ 2017 SCHMITZ W.J.L. MARLOES

CEMENTED TOTAL HIP ARTHROPLASTY AND IMPACTION BONE GRAFTING IN YOUNG PATIENTS

MARLOES W.J.L. SCHMITZ