Radial Head Fracture: a Potentially Complex Injury

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Radial head fracture: a potentially complex injury

Kaas, L.

Publication date 2012 Document Version Final published version

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Radial head fracture: A potentially complex injury

Laurens Kaas The printing of this thesis was financially supported by: Anna Fonds te Leiden, Arthrex Nederland BV, Biomet Nederland BV, Boehringer Ingelheim BV, Mathys Orthopaedics BV, Nederlandse Orthopaedische Vereniging, Synthes BV, Tornier NV, Smith & Nephew Nederland CV, and Raad van Bestuur Amphia ziekenhuis. which is gratefully acknowledged.

ISBN: 978-94-6169-218-4

Layout and printing: Optima Grafische Communicatie, Rotterdam, The Netherlands Cover design and artwork: Sandra Kaas

© Copyright 2012 L. Kaas. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, without prior written permission of the author. Radial head fracture: A potentially complex injury

ACADEMISCH PROEFSCHRIFT

ter verkrijging van de graad van doctor aan de Universiteit van Amsterdam op gezag van de Rector Magnificus prof. dr. D.C. van den Boom ten overstaan van een door het college voor promoties ingestelde commissie, in het openbaar te verdedigen in de Agnietenkapel op dinsdag 10 april 2012, te 14.00 uur

door

Laurens Kaas

geboren te Heerlen PROMOTIE COMMISSIE

Promotor: Prof. dr. C.N. van Dijk Co-promotor: Mevr. dr. D. Eygendaal Overige leden: Prof. dr. P.J.E. Bindels Prof. dr. P.M.M. Bossuyt Dr. M. Maas Prof. dr. F. Nollet Prof. dr. D.B.F. Saris Faculteit der Geneeskunde TAbLE OF COnTEnTS

Part I: General introduction and current issues

General introduction and outline of the thesis. Chapter 1: L. Kaas 9

Management of radial head fractures: current concepts. Chapter 2: L .Kaas, J.B. Jupiter, C.N. van Dijk, D. Eygendaal 23 Shoulder & Elbow 2011; 3(1): 34-40. (Invited review)

Part II: Epidemiology of radial head fractures and the relation to osteoporosis

Epidemiology of radial head fractures. Chapter 3: L. Kaas, R.P. van Riet, J.P.A.M. Vroemen, D. Eygendaal 41 Journal of Shoulder and Elbow Surgery 2010; 19(4): 520-523.

Radial head fractures and osteoporosis: a case-control study. Chapter 4: L. Kaas, I.N. Sierevelt, J.P.A.M. Vroemen, C.N. van Dijk, D. Eygendaal 49 Submitted.

Part III: Associated injuries of radial head fractures

Magnetic resonance imaging findings in 46 elbows with a radial head fracture. L. Kaas, J.L. Chapter 5: Turkenburg, R.P. van Riet, J.P.A.M. Vroemen, D. Eygendaal 59 Acta Orthopaedica 2010; 81(3): 373-376.

Magnetic resonance imaging in radial head fractures: Most injuries are not clinically relevant. L. Kaas, J.L. Turkenburg, R.P. van Riet, J.P.A.M. Vroemen,C.N. van Chapter 6: Dijk, D. Eygendaal 69 Journal of Shoulder and Elbow Surgery 2011;20(8): 1282-1288.

Ulnar collateral ligament instability of the elbow. Chapter 7: D. Eygendaal, L. Kaas Evidence-Based Orthopedics, 1st edition. M. Bhandari (ed.) Wiley- 83 Blackwell, Oxford; 2012: Page 781-786.

Part IV: Classification and treatment

Intra- and interobserver reliability of the Mason-Hotchkiss classification. Chapter 8: L. Kaas, M.A. van Hooft, M.P. Somford, L.H.G.J. Elmans, C.N. van Dijk, D. Eygendaal 97 Submitted.

Treatment of Mason type II radial head fractures: a systematic review. Chapter 9: L. Kaas, P.A.A. Struijs, D. Ring, C.N. van Dijk, D. Eygendaal 105 Submitted.

Results of the Judet bipolar radial head prosthesis in 33 patients with a minimal follow-up of 2 years. Chapter 10: L. Kaas, I.F. Kodde, R.P. van Riet, C.N. van Dijk, D. Eygendaal 117 Submitted.

Part V: General discussion, summary and conclusions

Discussion and summary Chapter 11: L. Kaas 131

Conclusions and recommendations for future research Chapter 12: L. Kaas 141 nederlandstalige algemene discussie, samenvatting, 147 conclusies en aanbevelingen voor toekomstig onderzoek

Dankwoord 156 bibliography 161

Curriculum Vitae 163 Part I General introduction and current issues

Chapter 1 General introduction

Laurens Kaas

“The fracture of the head of the radius is a serious injury, and whilst the prognosis is good for recovery of a useful elbow, rarely it is a normal elbow.”

Jones SG. Fractures of the head and neck of the radius - seperation of the upper radial epiphysis. New England Journal of Medicine 1935;212:914-7. 10 Chapter 1

FunCTIOnAL AnATOMy

The elbow plays an important role in the flexion-extension of the arm and supination- pronation of the forearm. It consists of three bones: the distal part of the humerus and the proximal parts of the ulna and the radius. These three bones articulate in the elbow in three separate joints: the radiohumeral (or radiocapitellar) joint, radioulnar joint and the ulnohumeral (or ulnotrochlear) joint. The radial head is an oval-shaped, concave dish that articulates with the spherical capitellum.1 It makes no contact with the capitellum during extension, but during flexion the radial head moves proximally and contact with the distal humerus increases. Supination decreases radiocapitellar contact and pronation increases the contact.2 The majority of the load from the forearm through the elbow is transferred by the radial head, especially in full extension. About 57% of the load applied to the hand crosses the radiocapitellar joint. The other 43% passes the ulnohumeral joint. However, this is highly dependent on the position of the elbow and muscle loading.3 The three elbow joints are surrounded by a joint capsule. It covers the tip of the olecranon, the coronoid process and radial fossa, but not the humeral epicondyles. The capsule is most lax at 80 degrees of flexion and holds a capacity of 25-30 mL in this position.1, 4 Patients with acute elbow injury therefore find this position more comfortable.1 The medial ligament complex consists of three parts: anterior, posterior and transverse segments (Fig. 1). The anterior and posterior ligaments originate at the medial epicondyle and insert to respectively the distal end of the coronoid process and medial margin of the semilunar notch of the olecranon. They contribute to valgus stability. The transverse part contributes little or nothing to elbow stability. The lateral collateral ligament complex contributes to

1 2 3

Figure 1: Anatomy of the medial collateral ligament complex. 1 = anterior, 2 = posterior, 3 = transverse ligament.

General introducti on 11 1

2 1

Figure 2: Anatomy of the lateral collateral complex. 1 = annular ligament, 2 = radial collateral ligament, 3 = lateral ulnar collateral ligament varus stability and consists of two parts: the radial collateral ligament and the annular ligament. The radial collateral ligament originates from the lateral epicondyle and inserts at the base of the coronoid process. The annular ligament originates and inserts on the lesser sigmoid notch and maintains contact between the radial head and ulna (Fig. 2).5 Elbow stability results from the interplay of the arti cular surfaces, ligaments and muscles. The radial head plays an important role in maintaining elbow stability. The three primary stati c stabilizers of the elbow are the ulnohumeral arti culati on and the medial and lateral collateral ligaments. Secondary constraints include the radial head, capsule and the common fl exor and extensor origins. The muscles around the elbow, especially the anconeus, triceps and biceps, functi on as dynamic stabilizers. If the coronoid process or medial collateral ligament (MCL) are injured, the radial head becomes a criti cal stabilizer.6 The radiocapitellar joint is the primary restraint to proximal migrati on of the radius. The interosseus membrane, a fi brous membrane between radius and ulna, and the triangular fi brocarti lage complex (TFCC) at the distal radioulnar joint also contribute to longitudinal stability of the forearm.7 Normal range of moti on (ROM) is from full extension of 0° to 145° of fl exion. Some hyperextension can be normal. Pronati on and supinati on show large normal variati ons, but usually are 85° of pronati on and 80° of supinati on. Interindividual variati on is wide.3 Full ROM is not necessary for normal acti viti es of daily living. Morrey et al. showed that for most acti viti es in daily life fl exion-extension of 130° to -30° and a pro-supinati on arc of 100° would be suffi cient.8 12 Chapter 1

RADIAL HEAD FRACTuRE

Fracture of the radial head is common and accounts for up to one third of all elbow fractures.9 The incidence in the general population is estimated at 2.5 to 2.9 per 10,000 inhabitants per year.10, 11 Fracture of the radial head was probably first described by Paul of Aegina (AD: 625-690)12: “The ulna and radius are sometimes fractured together and sometimes one of them only, either in the middle or at one end as the elbow or the wrist.” In the first decades of the 20th century it was stated that fracture of the radial head was caused by direct trauma, Flemming found that 75% of the cases were caused by direct injury.13 14 However, it is now generally agreed that the radial head fracture is the result of a fall on the outstretched hand with the elbow partially flexed and pronated.9, 15 (Fig. 3) Amis and Miller correlated elbow fractures to the angle of flexion of the elbow during a fall, the so-called “arc of injury”.15 In their experimental studies, the radial head fractures at a flexion angle < 80 degrees. With flexion of < 35 degrees either the coronoid process or the radial head (or both) may fracture.

Figure 3: Trauma mechanism of radial head fracture. (reproduced with permission) General introducti on 13 CLASSIFICATIOn 1 A variety of classifi cati on systems for radial head fractures have been developed, of which most are based on the classifi cati on introduced by Mason in his classic paper of 1954.16 In the Mason classifi cati on the fractures are classifi ed into three clinical types corresponding with a descripti on of the radiological fi ndings: a type I fracture is a fi ssure or marginal fracture without displacement, a type II fracture is a marginal sector fracture with displacement and type III fractures are comminuted, involving the whole radial head. Johnston added a fourth type to the Mason classifi cati on: radial head fracture with dislocati on of the elbow joint.17 Hotchkiss quanti fi ed the amount of displacement in his management- based classifi cati on: type I indicates a fracture that is ≤ 2 mm displaced, a type II fracture is > 2 mm displaced but amenable to internal fi xati on, a type III fracture is comminuted and not amenable to internal fi xati on.18 The Broberg and Morrey modifi cati on states that a displacement of ≥ 30% of the arti cular surface and a dislocati on of > 2 mm should be considered as a Mason type II fracture, opposed to the non-displaced type I fracture.19 Van Riet et al. developed the Mason-Mayo classifi cati on which includes the associated osseous and ligamentous injuries of the elbow by adding a suffi x for injury to the olecranon, coronoid and/or ligaments to the Mason classifi cati on.20 Mason type I fractures account for 50-67% of all radial head fractures, type II fractures for 14-36% and type III fractures for 5-19% of all radial head fractures. Concomitant elbow dislocati on (Mason-Johnston type IV) is seen in 2-14% of the radial head fractures.10, 11, 21

ASSOCIATED InjuRIES

In a large retrospecti ve study of 333 pati ents with a radial head fracture, clinically relevant concomitant injuries of the ipsilateral upper extremity were diagnosed in 39% of the pati ents and there is a strong correlati on between the likelihood of associated injury and the severity of the radial head fracture: the incidence increases from 20% in Mason type I fractures to 80% in type III fractures.21 The importance of these lesions in the treatment of pati ents with a radial head fracture is increasingly appreciated. Van Riet et al. found a clinically relevant lateral collateral ligament (LCL) lesion in 11% of the cases, a MCL lesion in 1.5% and a combinati on of both MCL and LCL lesions in 6%.21 3-14% of all radial head fractures is accompanied by a dislocati on of the elbow. It occurs aft er a fall on the (nearly) extended arm.21, 22 The combinati on of an elbow dislocati on, radial head fracture and coronoid fracture is called “the terrible triad of the elbow”, as it can result in severe joint instability and many post-traumati c complicati ons.23 As the radial head forcefully comes into contact with the capitellum under the axial loading, (osteo)chondral lesions can occur. Itamura et al. found osteochondral lesions in 96% of Mason type II and III fractures using 14 Chapter 1

magnetic resonance imaging (MRI).24 Capitellar fractures occur in 2%.21 Other associated injuries include acute longitudinal radioulnar dissociation (ALRUD) or Essex-Lopresti-lesion (radial head fracture, rupture of the membrana interossea between radius and ulna and a rupture of the triangular fibrocartilage complex (TFCC))25, 26, a Monteggia injury21 and severe anterior displacement of the radial head may cause injury to the radial nerve. Posterior interosseous nerve injury has also been reported in literature.9, 27

DIAGnOSIS

Patients with a radial head fracture usually present after a fall with elbow pain. On physical examination the radial head is painful on palpation and a hemarthros is seen. Elbow function, especially pro- and supination, is decreased because of pain. Ligamentous injury can be suspected in case of pain on palpation and/or ecchymosis of the medial and/or lateral aspects of the elbow. Aspiration of the hemarthrosis and intra-articular injection of a local anesthetic is helpful in determining if a restriction in motion, especially in rota- tional directions, is a consequence of pain or a true mechanical block of motion. In case of pain and swelling of the wrist and forearm, an ALRUD should be suspected. In case of a dislocation the forearm bones are displaced posterior to the distal humerus. Stability and neurovascular status should be examined. The diagnosis can be made with lateral, anteroposterior radiographs of the elbow. An additional radial head-capitellum view can be made. A positive fat-pad sign (Fig. 4), caused by the hemarthros, indicates presence of

Figure 4: Positive fat-pad sign (arrows) in a patient with a Mason type I radial head fracture of the left elbow. General introducti on 15 a radial head fracture. If one suspects an ALRUD, additi onal radiographs of the forearm and wrist should be made, to see if proximal migrati on of the radius is present. Rupture 1 of the membrana interossea can be diagnosed with MRI. A computer tomography (CT) scan is indicated in case of coronoid or capitellar fractures, to determine the amount of dislocati on in Mason type II and III fractures or for pre-operati ve planning.

TREATMEnT

Mason type I fractures are treated conservati vely with early moti on, with excellent results.9 Aspirati on of the elbow joint can be performed, as 1 mL of intra-arti cular fl uid decreases the range of moti on (ROM) with 2 degrees. Intra-arti cular injecti on of an anestheti c does not improve functi onal results.28, 29 The preferred treatment for Mason type II and III fractures is sti ll subject of discussion.30 Open reducti on and internal fi xati on (ORIF) can be performed in displaced fractures, amenable for stable reconstructi on and is indicated especially when forearm rotati on is limited by the fractured radial head.31, 32 If the fractured radial head cannot be reconstructed, an arthroplasty can be performed. The main goal of prostheti c replacement is to supply the secondary stabilizing functi on of the radial head and equalize load transmission across the elbow joint. Radial head prostheses are available in several designs, including monoblock metal implants33, 34, and bipolar prostheses35. In the past, silicon prostheses have been used, but they are abandoned due to high failure rates and silicon synoviti s.36-38 In general, excision of the radial head can only be performed in isolated comminuted radial head fractures or as a delayed treatment aft er initi ally conservati ve treated fractures that remain symptomati c, providing that the interosseus membrane and the MCL are intact.9 As Jones already stated in 193539: although the prognosis of radial head fractures is generally good, it rarely is a normal elbow. Persistent pain, reduced range of moti on, reduced grip strength, instability, and wrist pain are frequently reported aft er surgically or conservati vely treated radial head fractures.

OuTLInE OF THE THESIS

This thesis contains fi ve parts, each highlighti ng a diff erent aspect of the elbow with a fractured radial head. The fi rst part focuses on a general introducti on on the topic of radial head fractures and its current concepts in diagnosis and treatment. The second part aims to describe the epidemiology of radial head fractures and their associated osseous injuries in an European populati on. Radial head fractures and osteoporosis are linked, in order to explain the typical age and sex distributi on of pati ents with a radial head fracture. The incidence and clinical relevance of associated osseous, chondral and ligamentous lesions 16 Chapter 1

found with MRI of the elbow in patients with a radial head fracture are discussed in part III. In part IV we look to the inter- and intra-observer reliability of the Mason-Hotchkiss classification of radial head fractures. We also focus on treatment of type II radial head fractures with a systematic review of the current literature and the results of cemented and press-fit bipolar radial head prosthesis are discussed. A general discussion, conclusions of this thesis and recommendations for future research are discussed in the fifth and final part.

Part I: Introduction and current issues In chapter 2 current issues on radial head fractures are discussed, as a more extended introduction to the matter of this thesis. An overview of the most recent literature on diagnosis, fracture classification, associated injuries and treatment of radial head fractures is provided.

Part II: Epidemiology of radial head fractures Over the past years an increasing awareness on the importance of associated injuries in treating radial head fractures has increased.20, 40 Few reports on the epidemiology of radial head fractures and their associated osseous injuries are currently available and little is known about the incidence of radial head fractures and their associated injuries in the European population. Recent literature shows an increased mean age of female patients with radial head fractures compared with male patients with radial head fractures.21, 41 However, data on epidemiology of radial head fractures and specifically in relation to age distribution and male-female ratios of radial head fracture are scarce. Inchapter 3 it is our aim to describe the epidemiology of radial head fractures, especially the age distribution and male-female ratio, and their associated osseous injuries in the Dutch population. As age increases above 50 years, the number of females with a radial head fracture becomes significantly higher than the number of males with a radial head fracture. These findings suggest a possible link between radial head fractures and osteoporosis. This was the main research question in chapter 4 of the retrospective case-control study, comparing the bone mineral density of females ≥ 50 years old with a radial head fractures to women of the same age without a fracture. Our hypothesis was that female patients ≥ 50 years old with a radial head fracture have an increased relative risk on osteoporosis. Identifying radial head fractures as fragility fractures may improve case-finding for osteoporosis and preventing other fragility fractures, as radial head fractures occur earlier in life, compared to hip and vertebral fractures.42

Part III: Associated injuries of radial head fractures Radial head fractures are frequently accompanied by associated osseous, chondral and ligamentous injuries of the ipsilateral upper extremity.21, 22, 43 Especially ligamentous and General introducti on 17 chondral injuries commonly remain undetected by conventi onal radiographs, but may have consequences for treatment.9, 40, 44, 45 Clinically relevant associated injuries occur in 1 up to 39% of pati ents with a radial head fracture.21 On the other hand, Itamura et al. found concomitant lesions in up to 96% of Mason type II and III fractures using MRI of the elbow.24 Especially in pati ents with a more complex elbow trauma, such as elbow dislocati on, diagnosis and understanding of the concomitant injuries is of great importance for an adequate treatment.9, 46 The fi rst aim of the study in chapter 5 was to describe the incidence of associated injuries in pati ents with a radial head fracture detected with MRI of the elbow. The hypothesis was that in the general populati on with a radial head fracture, the incidence of associated injuries found with MRI is lower than the incidence reported by Itamura et al.43 The clinical relevance of these injuries is unclear. In chapter 6 the pati ents with a radial head fracture who underwent a MRI of the elbow were evaluated aft er at least 12 months. It was our hypothesis that not all of the injuries found in these pati ents with MRI are of clinical relevance, as the incidence of clinically relevant associated radial head fractures is lower21, compared to the incidence reported by Itamura et al.43 MCL injury can be seen in radial head fractures, especially in pati ents with concomitant elbow dislocati on, and can cause chronic valgus elbow instability in these pati ents. Injury to the MCL of the elbow is discussed in a broader spectrum and more in detail in chapter 7, as this injury can also occur in (throwing) athletes. As litt le is known about this injury and it is uncommon in daily orthopaedic practi ce, we performed a literature search on the subject of MCL injury and tried to answer the most important questi ons on incidence, eti ology, diagnosis and treatment of this injury.

Part IV: Classifi cati on and treatment of radial head fractures The fi nal part of this thesis focuses on the classifi cati on and treatment of radial head fractures. As menti oned earlier, radial head fractures can be classifi ed according to the Mason classifi cati on, or one of its modifi cati ons.16,18-20 A fracture classifi cati on system should name and describe fractures according to their characteristi cs, providing a hierarchy of those characteristi cs. It should provide a guideline for treatment or interventi on and should predict a clinical outcome. Ideally, a classifi cati on should be valid, reliable and reproducible by observers with diff erent levels of experience.47, 48 Few studies are currently available on the inter- and intra-observer agreement of the Mason classifi cati on and its modifi cati ons.20, 49-52 To our knowledge, only one study of the Mason-Hotchkiss classifi cati on is available50. The inter- and intra-observer reliability of the Mason-Hotchkiss classifi cati on are discussed in chapter 8. Only a few studies on inter- and intra-observer reliability of the Mason classifi cati on or its modifi cati ons are available. None of these studies provide informati on on whether the clinicians’ experience improves agreement. It was our hypothesis that experience will improve the agreement. 18 Chapter 1

Treatment of Mason type I fractures is non-operative, with early mobilization, and type III fractures should be managed operatively. However, the best treatment of type II fractures that are not associated with other fractures or ligament injuries (so-called “isolated fractures”) is still debated. Some favor non-operative treatment and other favor open reduction and internal fixation (ORIF).31 The aim of the systematic review in chapter 9 was to combine the results of relevant studies on treatment of displaced partial articular radial head fractures without associated elbow dislocation or other elbow fractures, to inform the debate between operative and non-operative treatment. We hypothesized that current evidence is not strong enough to provide a definitive answer to the optimal treatment of the isolated Mason type II fracture. Comminuted, type III fractures, which are not amenable for reconstruction, can be treated with a radial head prosthesis or excision of the radial head. Replacement of the comminuted fractured radial head is regarded to be the best treatment option when the forearm or elbow is unstable as a result of concomitant injuries.9 The floating radial head prosthesis is a bipolar radial head prosthesis and is available in two types: a long-stemmed cemented prosthesis and short-stemmed press-fit prosthesis. The more recently introduced press-fit system possibly allows easier revision, which may be required in young, demanding patients and it is easier to insert, as the stem is shorter and straight. Only a few small case series on the short and medium term results of the cemented bipolar design have been published35, 53-57, and to our knowledge no results of the more recent, press-fit bipolar floating radial head prosthesis have been published. In chapter 10, the main goal was to describe the clinical results of the cemented and press-fit bipolar radial head prosthesis. It was our hypothesis that bipolar radial head implants have comparable clinical results to other implants and that there is no difference in functional outcome between the press-fit and cemented design.

Part V: General discussion, summary and conclusions The chapter 11 of this thesis is the general discussion in which the previous chapters are put into perspective, with a special focus on the relevance of the results for daily clinical practice. Furthermore, conclusions are drawn and recommendations for future research are discussed in final chapter 12. General introducti on 19

REFEREnCE LIST

(1) van Glabbeek F, Clockaerts S. Functi onal anatomy of the elbow. In: Eygendaal D, editor. The Elbow. 1 1 ed. Nieuwegein: Arko Sports Media; 2009. p. 15-34. (2) McGinley JC, Hopgood BC, Gaughan JP, Sadeghipour K, Kozin SH. Forearm and elbow injury: the infl uence of rotati onal positi on. J Bone Joint Surg Am 2003 Dec; 85-A(12): 2403-9. (3) van Riet RP, An KN. Biomechanics of the elbow. In: Eygendaal D, editor. The Elbow. 1 ed. Nieuwe- gein: Arko Sports Media; 2009. p. 27-34. (4) Morrey B. Anatomy of the Elbow Joint. In: Morrey B, Sanchez-Sotelo J, editors. The Elbow and Its Disorders. 4 ed. Philadelphia: Saunders; 2009. p. 11-38. (5) Safran MR, Baillargeon D. Soft -ti ssue stabilizers of the elbow. J Shoulder Elbow Surg 2005 Jan; 14(1 Suppl S):179S-85S. (6) O’Driscoll SW, Jupiter JB, King GJ, Hotchkiss RN, Morrey BF. The unstable elbow. Instr Course Lect 2001;50: 89-102. (7) Hotchkiss RN, An KN, Sowa DT, Basta S, Weiland AJ. An anatomic and mechanical study of the interosseous membrane of the forearm: pathomechanics of proximal migrati on of the radius. J Hand Surg Am 1989 Mar;14(2 Pt 1):256-61. (8) Morrey BF, Askew LJ, Chao EY. A biomechanical study of normal functi onal elbow moti on. J Bone Joint Surg Am 1981 Jul;63(6): 872-7. (9) van Riet RP, van Glabbeek F, Morrey BF. Radial Head Fracture: General Considerati ons, Conservati ve Treatment and Open Reducti on and Internal Fixati on. In: Morrey B, Sanchez-Sotelo J, editors. The Elbow and its Disorders. 4 ed. Philadelphia: Saunders; 2009. p. 359-81. (10) Herbertsson P, Josefsson PO, Hasserius R, Karlsson C, Besjakov J, Karlsson M. Uncomplicated Mason type-II and III fractures of the radial head and neck in adults. A long-term follow-up study. J Bone Joint Surg Am 2004 Mar;86-A(3): 569-74. (11) Kaas L, van Riet RP, Vroemen JP, Eygendaal D. The incidence of associated fractures of the upper limb in fractures of the radial head. Strategies Trauma Limb Reconstr 2008 Sep;3(2): 71-4. (12) Aegina P. Fractures and Dislocati on. London: New Sydenham Society; 1846. (13) Cutler CW. Fractures of the head and neck of the radius. Annals of Surgery 1926;83(2): 267-78. (14) Flemming CW. Fractures of the head of the radius. Proceedings of the Royal Society of Medicine 1932;25(7): 1011-5. (15) Amis A, Miller J. Mechanisms of elbow fractures: an investi gati on using impact tests in vitro. Injury 1995;26(3): 163-8. (16) Mason ML. Some observati ons on fractures of the head of the radius with a review of one hundred cases. Br J Surg 1954;42: 123-32. (17) Johnston GW. A follow-up of one hundred cases of fracture of the head of the radius with a review of the literature. Ulster Med J 1962 Jun 1;31: 51-6. (18) Hotchkiss RN. Displaced fractures of the radial head: internal fi xati on or excision? J Am Acad orthop Surg 1997;5: 1-10. (19) Broberg MA, Morrey BF. Results of treatment of fracture-dislocati ons of the elbow. Clin Orthop Relat Res 1987 Mar;(216): 109-19. (20) van Riet RP, Morrey BF. Documentati on of associated injuries occurring with radial head fracture. Clin Orthop Relat Res 2008 Jan;466(1): 130-4. (21) van Riet RP, Morrey BF, O’Driscoll SW, van Glabbeek F. Associated injuries complicati ng radial head fractures: a demographic study. Clin Orthop Relat Res 2005;441: 351-5. 20 Chapter 1

(22) Kaas L, van Riet RP, Vroemen J, Eygendaal D. The epidemiology of radial head fractures. J Shoulder Elbow Surg 2010 Jun 1; 19(4): 520-3. (23) Ring D, Jupiter JB, Zilberfarb J. Posterior dislocation of the elbow with fractures of the radial head and coronoid. J Bone Joint Surg Am 2002 Apr; 84-A(4): 547-51. (24) Itamura J, Roidis N, Mirzayan R, Vaishnav S, Learch T, Shean C. Radial head fractures: MRI evaluation of associated injuries. J Shoulder Elbow Surg 2005 Jul; 14(4): 421-4. (25) Essex-Lopresti P. Fractures of the radial head with distal radio-ulnar dislocation; report of two cases. J Bone Joint Surg Br 1951 May; 33B(2): 244-7. (26) Sloots CE, Frolke JP. [Wrist pain following radial head fracture caused by a tear in the interosseous membrane (Essex-Lopresti lesion)]. Ned Tijdschr Geneeskd 2007 Jan 27; 151(4): 248-52. (27) Sudhahar TA, Patel AD. A rare case of partial posterior interosseous nerve injury associated with radial head fracture. Injury 2004 May; 35(5): 543-4. (28) Chalidis BE, Papadopoulos PP, Sachinis NC, Dimitriou CG. Aspiration alone versus aspiration and bupivacaine injection in the treatment of undisplaced radial head fractures: a prospective randomized study. J Shoulder Elbow Surg 2009 Sep; 18(5): 676-9. (29) McGuigan FX, Bookout CB. Intra-articular fluid volume and restricted motion in the elbow. J Shoul- der Elbow Surg 2003 Sep; 12(5): 462-5. (30) Struijs PA, Smit G, Steller EP. Radial head fractures: effectiveness of conservative treatment versus surgical intervention. A systematic review. Arch Orthop Trauma Surg 2007 Feb; 127(2): 125-30. (31) Lindenhovius AL, Felsch Q, Ring D, Kloen P. The long-term outcome of open reduction and internal fixation of stable displaced isolated partial articular fractures of the radial head. J Trauma 2009 Jul; 67(1): 143-6. (32) Ikeda M, Sugiyama K, Kang C, Takagaki T, Oka Y. Comminuted fractures of the radial head. Compari- son of resection and internal fixation. J Bone Joint Surg Am 2005 Jan; 87(1): 76-84. (33) Doornberg JN, Parisien R, van Duijn PJ, Ring D. Radial head arthroplasty with a modular metal spacer to treat acute traumatic elbow instability. J Bone Joint Surg Am 2007 May; 89(5): 1075-80. (34) Harrington IJ, Sekyi-Otu A, Barrington TW, Evans DC, Tuli V. The functional outcome with metallic radial head implants in the treatment of unstable elbow fractures: a long-term review. J Trauma 2001 Jan; 50(1): 46-52. (35) Judet T, Garreau de LC, Piriou P, Charnley G. A floating prosthesis for radial-head fractures. J Bone Joint Surg Br 1996 Mar; 78(2): 244-9. (36) Swanson AB, Jaeger SH, La RD. Comminuted fractures of the radial head. The role of silicone-implant replacement arthroplasty. J Bone Joint Surg Am 1981 Sep; 63(7): 1039-49. (37) VanderWilde RS, Morrey BF, Melberg MW, Vinh TN. Inflammatory arthritis after failure of silicone rubber replacement of the radial head. J Bone Joint Surg Br 1994 Jan; 76(1): 78-81. (38) Moon JG, Southgate RD, Fitzsimmons JS, O’Driscoll SW. Arthroscopic removal of the failed silicone radial head prosthesis. Knee Surg Sports Traumatol Arthrosc 2009 Oct; 17(10): 1243-8. (39) Jones SG. Fractures of the head and neck of the radius - seperation of the upper radial epiphysis. New England Journal of Medicine 1935; 212: 914-7. (40) Davidson PA, Moseley JB, Jr., Tullos HS. Radial head fracture. A potentially complex injury. Clin Orthop Relat Res 1993 Dec; (297): 224-30. (41) Gebauer M, Rucker AH, Barvencik F, Rueger JM. [Therapy for radial head fractures]. Unfallchirurg 2005 Aug; 108(8): 657-67. (42) Mallmin H, Ljunghall S, Persson I, Naessen T, Krusemo UB, Bergstrom R. Fracture of the distal forearm as a forecaster of subsequent hip fracture: a population-based cohort study with 24 years of follow-up. Calcif Tissue Int 1993 Apr; 52(4): 269-72. General introducti on 21

(43) Itamura J, Roidis N, Mirzayan R, Vaishnav S, Learch T, Shean C. Radial head fractures: MRI evaluati on of associated injuries. J Shoulder Elbow Surg 2005 Jul;14(4): 421-4. (44) Steinmann SP. Coronoid process fracture. J Am Acad Orthop Surg 2008 Sep;16(9): 519-29. 1 (45) Nalbantoglu U, Gereli A, Kocaoglu B, Aktas S, Turkmen M. Capitellar carti lage injuries concomitant with radial head fractures. J Hand Surg (Am) 2009;33(9): 1602-7. (46) O’Driscoll SW, Jupiter JB, Cohen MS, Ring D, McKee MD. Diffi cult elbow fractures: pearls and pitf alls. Instr Course Lect 2003;52: 113-34. (47) Marti n JS, Marsh JL. Current classifi cati on of fractures. Rati onale and uti lity. Radiol Clin North Am 1997 May;35(3): 491-506. (48) Dirschl D, Cannada L. Classifi cati on of Fractures. In: Bucholz R, Heckman J, Court-Brown C, editors. Rockwood and Green’s Fractures in Adults. 6 ed. Philadelphia: Lipincot Williams & Wilkins; 2006. p. 43-4. (49) Matsunaga FT, Tamaoki MJ, Cordeiro EF, Uehara A, Ikawa MH, Matsumoto MH, et al. Are classifi cati ons of proximal radius fractures reproducible? BMC Musculoskelet Disord 2009; 10: 120. (50) Sheps DM, Kiefer KR, Boorman RS, Donaghy J, Lalani A, Walker R, et al. The interobserver reliability of classifi cati on systems for radial head fractures: the Hotchkiss modifi cati on of the Mason classifi cati on and the AO classifi cati on systems. Can J Surg 2009 Aug; 52(4): 277-82. (51) Doornberg J, Elsner A, Kloen P, Marti RK, van Dijk CN, Ring D. Apparently isolated parti al arti cular fractures of the radial head: prevalence and reliability of radiographically diagnosed displacement. J Shoulder Elbow Surg 2007 Sep;16(5): 603-8. (52) Morgan SJ, Groshen SL, Itamura JM, Shankwiler J, Brien WW, Kuschner SH. Reliability evaluati on of classifying radial head fractures by the system of Mason. Bull Hosp Jt Dis 1997;56(2): 95-8. (53) Dotzis A, Cochu G, Mabit C, Charissoux JL, Arnaud JP. Comminuted fractures of the radial head treated by the Judet fl oati ng radial head prosthesis. J Bone Joint Surg Br 2006 Jun; 88(6): 760-4. (54) Popovic N, Lemaire R, Georis P, Gillet P. Midterm results with a bipolar radial head prosthesis: radiographic evidence of loosening at the bone-cement interface. J Bone Joint Surg Am 2007 Nov; 89(11):2469-76. (55) Brinkman JM, Rahusen FT, de Vos MJ, Eygendaal D. Treatment of sequelae of radial head fractures with a bipolar radial head prosthesis: good outcome aft er 1-4 years follow-up in 11 pati ents. Acta Orthop 2005 Dec;76(6): 867-72. (56) Burkhart KJ, Matt yasovszky SG, Runkel M, Schwarz C, Kuchle R, Hessmann MH, et al. Mid- to long- term results aft er bipolar radial head arthroplasty. J Shoulder Elbow Surg 2010 Oct; 19(7): 965-72. (57) Celli A, Modena F, Celli L. The acute bipolar radial head replacement for isolated unreconstructable fractures of the radial head. Musculoskelet Surg 2010 May;94 Suppl 1:S3-S9.

Chapter 2 Treatment of radial head fractures: Current concepts

Laurens Kaas, Jesse B. Jupiter, C. Niek van Dijk, Denise Eygendaal

Shoulder & Elbow 2011; 3(1): 34-40. (Invited review) 24 Chapter 2

AbSTRACT

Radial head fractures are common injuries and are accompanied by clinically relevant associated injuries in over one third of the patients. They are commonly classified by the Mason classification, or one of its modifications. Type I fractures are treated conservatively with early mobilization. Type II fractures can be treated conservatively or by open reduction and internal fixation (ORIF), depending on fragment size and dislocation. Bony restriction in forearm rotation is an indication for surgical treatment. Type III fractures are treated surgically, by means of ORIF, prosthetic replacement or excision. Comminuted fractures with > 3 fragments are regarded by some authors as unsuitable for ORIF. How- ever, optimal treatment of type II and III fractures is still subject of debate and there is a strong need of randomized clinical trials and uniform fracture classification and outcome measures. Management of radial head fractures 25

InTRODuCTIOn

Although the prognosis of most isolated radial head fractures is good1, in 1935 Jones2 already stated that: “The fracture of the head of the radius is a serious injury, and whilst the prognosis is good for recovery of a useful elbow, rarely it is a normal elbow.” Complica- 2 ti ons such as loss of elbow moti on or persistent elbow pain are frequently encountered.3-6 Over the past few years, there is an increasing understanding of the trauma mechanism of radial head fractures, of the clinical importance of their associated injuries and of the role of the radial head in elbow biomechanics. In this review the incidence and eti ology of radial head fractures are described, an overview of the classifi cati on of radial head fractures is given, the importance of associated injuries is discussed and a treatment rati onale for radial head fractures is suggested.

InCIDEnCE AnD ETIOLOGy

Fracture of the radial head accounts for up to one third of all elbow fractures.1 The incidence is esti mated at 2.5 to 2.9 per 10,000 per year.5, 7 Radial head fractures are most oft en the result from a fall on the outstretched hand with the elbow parti ally fl exed and pronated.1, 8 Amis and Miller correlated elbow fractures to the angle of fl exion of the elbow during a fall, the so-called “arc of injury”.8 In their experimental studies, the radial head only fractures at a fl exion angle between 0 and 80 degrees. With fl exion of < 35 degrees either the coronoid process or the radial head (or both) may fracture. The radial head plays an important role in maintaining elbow stability. The ulnohumeral arti culati on in combinati on with the medial and lateral collateral ligaments are the three primary stati c stabilizers of the elbow. Secondary constraints include the radial head, the joint capsule and the common fl exor and extensor origins. The muscles around the elbow, especially the anconeus, triceps and biceps, functi on as dynamic stabilizers.9 If the coronoid process or medial collateral ligament (MCL) are injured, the radial head becomes a criti cal stabilizer.9

FRACTuRE CLASSIFICATIOn

A variety of classifi cati on systems for radial head fractures have been developed, of which most are based on the classifi cati on introduced by Mason in his classic paper of 1954.3 (Table I) According to the Mason classifi cati on, radial head fractures are divided into three types corresponding to the radiological fi ndings: A type I fracture is a fi ssure or marginal fracture without displacement, a type II fracture is a marginal sector fracture with displacement and type III fractures are comminuted, involving the enti re radial head. Johnston 26 Chapter 2

Type Classification type and description Mason Johnston Hotchkiss Broberg and Morrey I Undisplaced Undisplaced <2 mm dislocation <2 mm dislocation II Displaced Displaced >2 mm dislocation, >2 mm dislocation + >30% reconstructable articular surface III Comminuted Comminuted Comminuted, Comminuted unreconstructable IV - Radial head fracture + - - elbow dislocation Table 1: Description of the original Mason classification7, and a description of the Johnston-modification10, the Hotckiss-modification12 and the Broberg and Morrey modification14 of the Mason classification.

added a fourth type to the Mason classification: radial head fracture with dislocation of the elbow joint.10 Intra-observer agreement of the Mason classification is satisfactory and inter-observer agreement moderate.11 Hotchkiss quantified the amount of displacement in his management-based classification: type I indicates a fracture that is ≤ 2 mm displaced, a type II fracture is > 2 mm displaced but amenable to internal fixation, a type III fracture is comminuted and not amenable to internal fixation.12 The inter-observer reliability of the Hotchkiss modification is moderate, with a κ-statistic of 0.585.13 The Broberg and Morrey modification states that a displacement of ≥ 30% of the articular surface and a dislocation of > 2 mm should be considered as a Mason type II fracture, opposed to the non-displaced type I fracture.14 Intra-observer agreement is excellent, and inter-observer agreement is moderate.15 van Riet et al. developed the Mason-Mayo classification which includes the associated osseous and ligamentous injuries of the elbow by adding a suffix for injury to the olecranon, coronoid and/or ligaments to the Mason classification.16 Intra-observer agreement of the Mason-Mayo classification is fair, and inter-observer agreement ranges from fair to moderate.11 The AO Foundation developed the AO classification for long bone fractures.17 Fractures of the proximal radius and ulna are divided into 3 types: type A (extra-articular fracture of radius and/or ulna), type B (intra-articular fracture of one forearm bone, with or without an extra-articular fracture of the other bone) and type C (intra-articular fracture of both radius and ulna). The fractures are then subdivided into groups 1, 2 and 3 for involvement of radius and/or ulna, and the location of the fracture line. These are then further subdivided into subgroups 0.1, 0.2 or 0.3, based on fracture characteristics as comminution. Inter-observer reliability ranges from poor to fair and intra-observer agreement is graded as poor, possibly due to the complexity of the AO classification.11, 13 This classification system for radial head fractures is less frequently used in daily clinical practice. The original Mason classification and its variations are all commonly used in literature. For this current concept article the original Mason classification3 is used for practical rea- Management of radial head fractures 27 sons: when discussing management of radial head fractures, the original arti cles uniformly have used the Mason classifi cati on or one of its modifi cati ons. These modifi cati ons can all be reduced to original the Mason classifi cati on, allowing discussion of the combined results. If the results of a single arti cle are referred, the classifi cati on of this original research is used. 2

ASSOCIATED InjuRIES

The importance of concomitant injuries in the treatment of pati ents with a radial head fracture is increasingly appreciated. In a retrospecti ve study by van Riet et al.18 of 333 pati ents with a radial head fracture, clinically relevant associated injuries of the ipsilateral upper extremity were diagnosed in 39% of the pati ents. There is a strong correlati on between the likelihood of associated injury and the severity of the radial head fracture: the incidence can increase from 20% in Mason type I fractures to 80% in type III fractures.18 Loss of corti cal contact between fracture fragments in type II fractures is also strongly predicti ve for a complex injury patt ern.19 Using magneti c resonance imaging (MRI), associated injuries ranging from ligamentous injuries to capitellar bone bruise can be found in 76 to 96% of the pati ents with a radial head fracture.20, 21 However, the majority of these injuries probably have no clinical relevance.22 Hausmann et al. found parti al lesions of the interosseous membrane (IOM)with MRI in 9 of 14 pati ents with a Mason type I fracture, of which 7 reported pain in the region on the distal IOM.

Ligamentous injuries As the radial head fractures with the elbow in fl exion and pronati on with the hand fi xed on the ground, the lateral collateral ligament (LCL) ruptures as a result of the forced supinati on of the forearm when the body rotates internally on the elbow under axial compression as the body approaches the ground. If the rotati onal and axial forces conti nue a posterolateral dislocati on fi nally can occur, with or without rupture of the MCL. The MCL can also rupture as a result of a valgus moment.23, 24 Ligamentous injuries are found with MRI in 61 to 80% of the pati ents with a radial head fracture.21 van Riet et al. found a clinically relevant LCL lesion in 11% of the cases, a MCL lesion in 1.5% and a combinati on of both MCL and LCL lesions in 6%.18

Elbow dislocati on, coronoid process fractures and the “terrible triad of the elbow” Three to 14% of all radial head fractures is accompanied by a posterolateral dislocati on of the elbow. It occurs aft er a fall on the (nearly) extended arm.7, 18 During posterolateral dislocati on the ligamentous structures and the capsule are ruptured in a circle from lateral to medial.23 The axial compression and supinati on cause the LCL to rupture, which 28 Chapter 2

results in a posterolateral rotator movement of the forearm. After rupture of the dorsal and ventral elbow capsule the elbow joint dislocates as a result of the axial forces. The coronoid process is pushed under the trochlea of the humerus, causing a shear fracture. Until this phase the dislocated elbow can self-reduce. Finally the MCL ruptures asthe coronoid process is pushed further under and behind the trochlea, but this does not occur in all cases.9 The combination of an elbow dislocation, radial head fracture and coronoid fracture is called “the terrible triad of the elbow” because it can result in severe joint instability and many post-traumatic complications.25

ulnar fractures A concomitant fracture of the ulna occurs in 1.2-12% of the patients with a radial head fracture.7, 18 A special variety of the combination of a radial head fracture and an ulnar fracture is the Monteggia lesion (radial head dislocation and fracture of the distal one third of the ulna). It occurs after a fall on the outstretched arm with the forearm in hyper- pronation. In complex proximal ulna fractures, Monteggia-like dislocation of the fractured radial head has been described as well.

Capitellar injuries As the radial head forcefully comes into contact with the capitellum under the axial loading, osteochondral lesions can occur. Capitellar injuries are seen with MRI in 39 to 96% of patients with a radial head fracture.21, 26 Capitellar fractures occur in 2%.18

Other associated injuries - An acute longitudinal radioulnar dissociation (ALRUD) or Essex-Lopresti-lesion results from a high-energy axial loading, which causes a radial head fracture, rupture of the IOM between radius and ulna and a rupture of the triangular fibrocartilage complex.27, 28 Although this is a rare injury, Hausmann et al. reported on partial ruptures of the IOM diagnosed with MRI in 9 of 14 patients with a Mason type I fracture, suggesting that injuries of the IOM are more frequent than generally expected.29 - Severe anterior displacement of the radial head may cause injury to the radial nerve.1 Posterior interosseus nerve injury after radial head fracture has also been reported in literature.30, 31 - Brachial artery injury occurs in 0.3 to 1.7% of the elbow dislocations.32 Neurologic problems occur in 20% of the elbow dislocations. The ulnar and median nerve are most susceptible.33 Management of radial head fractures 29

ASSESSMEnT AnD IMAGInG

Pati ents with a radial head fracture usually present aft er a fall with elbow pain. On physical examinati on the radial head is painful on palpati on and an heamarthrosis is seen. Elbow range of moti on, especially pro- and supinati on, is decreased because of pain. Ligamen- 2 tous injury can be suspected in case of pain on palpati on and/or ecchymosis of the medial and/or lateral aspects of the elbow. Aspirati on of the haemarthrosis and intra-arti cular injecti on of a local anestheti c can be helpful in determining if a restricti on in moti on is a consequence of pain or a true mechanical block. In case of pain and swelling of the wrist and forearm an ALRUD should be suspected. In case of an elbow dislocati on the forearm bones are displaced in a posterolateral directi on in relati on to the distal humerus in most cases. Stability and neurovascular status should be examined. The diagnosis can be made with lateral and anteroposterior (AP) radiographs of the elbow. A positi ve fat-pad sign, caused by the hemarthrosis, can indicate presence of a radial head fracture. An additi onal radial head-capitellum (RHC) view is assumed to reveal the degree of displacement.34 On the other hand, no signifi cant increase in inter- and intra-observer agreement is seen if this RHC view is performed.35 If one suspects an ALRUD, additi onal radiographs of the forearm and wrist should be made, to see if proximal migrati on of the radius is present. Rupture of the interosseous membrane can be diagnosed with MRI. A computer tomography (CT) scan is indicated in case of coronoid or capitellar fractures, or in Mason-Broberg type II fractures to determine the amount of dislocati on or for pre-operati ve planning.

TREATMEnT

Restorati on of stability and a pain free range of moti on (especially rotati on and extension) is the main objecti ve when treati ng radial head fractures. In Mason type I fractures this will be achieved in most cases, but more complex radial head fractures, with or without associated injuries, demand a careful and individual approach. Complex injuries with forearm instability, such as an ALRUD or coronoid fracture, require restorati on of the ulnohumeral joint and the radiocapitellar contact in order to maintain a stable elbow joint.36 In this review, we focus on the treatment of the radial head fracture as such. Concomitant injuries should be treated within their own merit and are not discussed.

Mason type I It is generally agreed that type I fractures can be treated with early mobilizati on. Aspira- ti on of the elbow joint can be performed, as 1cc of intra-arti cular fl uid decreases the range of moti on (ROM) with 2 degrees. Intra-arti cular injecti on of an anaestheti c does not improve functi onal results.37, 38 Good results are achieved in 85 to 95%.6, 24 30 Chapter 2

Figure 1: Lateral radiograph of a right elbow Figure 2: Lateral radiograph of a right elbow with a with a Mason type II fracture. Mason type II fracture after ORIF.

Mason type II The treatment of type II radial head fractures is still at debate. Dislocation of > 2 mm and a lack of forearm rotation due to bony obstruction of the malformated radial head have been regarded as an indication for surgical treatment.12 Several techniques and materials for ORIF, e.g. Herbert screws39, FFS-screws40, biodegradable screws41, 42 and mini plates43-45, have been described with in general satisfactory results of > 85% (Figs 1 and 2). Biodegrad- able screws have comparable outcomes compared to standard implant materials for ORIF of radial head fractures.42 In a study with long-term results of ORIF in 16 patients are good

Figure 3: Anteroposterior radiograph of a comminuted and dislocated radial head fracture. Management of radial head fractures 31 in 81%, aft er an average follow-up of 22 years.46 Arthroscopic reducti on and percutaneous fi xati on of Mason type II (and III) fractures is described by Michels et al.47 and Rolla et al.48 This minimally invasive technique is technically demanding, but adequate reducti on under visualizati on and evaluati on of associated injuries can be achieved. So far, the arthroscopic technique has not been proven to give superior results in the treatment of radial head 2 fractures, in comparison to ORIF. Akesson et al. reviewed the long-term results of conservati ve treatment of Mason-Bro- berg type II fractures with at least 2 mm of displacement: 82 to 100% had no or minor elbow complaints and a good functi onal outcome.49, 50 Therefore, Lindenhovius et al. suggest that stable, isolated Mason-Broberg type II fractures with unrestricted forearm rotati on can be treated conservati vely, as ORIF does not necessary leads to bett er functi onal results.46 If the elbow remains symptomati c, a delayed radial head excision5, 51, 52 or replacement with a radial head prosthesis can be performed.53 We conclude that randomized clinical trials are in need to determine which type II fractures can be treated conservati vely and which require surgical treatment.

Mason type III Treatment of type III fractures is usually surgical: ORIF, prostheti c replacement or excision (Fig. 3). The preferred surgical treatment is sti ll in debate. Comminuted fractures can be treated with ORIF if a stable, reliable reconstructi on can be achieved. Successful treatment of type III fractures with ORIF has been reported in 80 to 100%.40, 44, 54 However, in a study by Ring et al., 10 of 14 pati ents with a fracture consisti ng of > 3 fragments treated with

Figure 4: Lateral radiograph of a left elbow aft er radial head replacement with a bipolar radial head prosthesis and LCL reconstructi on. 32 Chapter 2

ORIF needed a delayed excision due to failure of the osteosynthesis, non-union and/or a poor forearm rotation. In these cases, the authors advise prosthetic replacement.55 Radial head prostheses come in a variety of designs: monoblock or modular prostheses are available. The modular prostheses can be monopolar or bipolar (Fig. 4). The fixation of the implant can be cemented, press fit or “intentional loose fit”.56-58 Intentional loose fit prostheses allow a degree of play, which compensates the anatomic difference of the native and prosthetic radial head during elbow motion. Fixed stems rely on their position and approximation of the native anatomy to achieve congruency with the capitellum and the lesser sigmoid notch. Bipolar prostheses (available in cemented and press fit stem varieties) allow centering of the radiocapitellar joint as a result of an articulation at the head-neck junction and are more forgiving in alignment of the prosthesis in relation to the capitellum.59 The bipolar implants are believed to reduce forces across the capitellum60; however clinical studies to support this theory are not available yet. Cadaveric studies show that bipolar implants provide less mechanic stability, compared to monopolar implants.60, 61 This has not been supported by clinical studies yet. Short to medium-term results of radial head prostheses are promising.62-64 Complica- tions as overstuffing, nerve injury and dislocation of the implant have been described in up to 20%.57, 63, 65, 66 Long term results are incompletely defined. Harrington et al. report on good to excellent long term results in 16 of 20 patients with metal prosthetic radial head spacer and a mean follow-up of 12.1 (range: 6 to 29) years.57 Popovic et al. 63 report on radiographic evidence of loosening at the bone-cement interface and osteolysis of the proximal radius in patients with a bipolar floating Judet prosthesis with satisfactory clinical results after a mean follow-up of 8.4 years, possibly due to wear of the polyethylene part of the prosthesis. However, Burkhart et al. did not find this proximal osteolysis in 16 elbows with a follow-up of 8.8 years and claim that it is caused by insufficient cementing techniques.67 One randomized clinical trial to compare ORIF to prosthetic replacement in Mason type III fractures is currently available. Ruan et al.68 found favorably results for bipolar prosthetic replacement, compared to ORIF, in trial of 22 Mason type III fractures and a follow-up of 10 to 27 months. Good to excellent result were achieved in 13 of 14 patients in the prosthetic replacement group, compared to 1 of 8 patients in the ORIF group. How- ever, the small patient number, short follow-up and inclusion of 2 delayed cases make the reliable interpretation of these results difficult. Once the standard treatment for type III fractures3, excision of the radial head is now reserved for isolated comminuted fractures in which a reliable osteosynthesis cannot be achieved. However, with type III radial head fractures associated injuries occur in >75% of the patients.18;20 After radial head excision, elbow stability should be tested during surgery to exclude ligamentous injury. Satisfactory long-term functional outcomes have been reported after primary or delayed radial head excision.52, 69-72 However, wrist pain due to Management of radial head fractures 33 proximal migrati on of the radius and decreased grip strength are known complicati ons44 and most of these studies do not take associated injuries into account. Some authors suggest that in absence of the radial head ulnohumeral osteoarthriti s is accelerated due to the altered elbow kinemati cs73: about 57% of the load applied to the hand crosses the radiocapitellar joint in an intact elbow, but is dependent on the positi on of the elbow and 2 muscle loading.74 Excision of the radial head can lead to valgus instability, especially in case of associated MCL injury.73, 75 Ikeda et al. concluded aft er a study of 28 pati ents with a Mason type III fracture that pati ents treated with ORIF had greater strength en bett er functi on, compared to pati ents treated with resecti on.44 Excision cannot be recommended for pati ents who engage in prolonged heavy use of their upper extremiti es, such as heavy manual labourers or athletes, nor in pati ents with concomitant injury.76

DISCuSSIOn

Radial head fractures are common and up to one-third have concomitant injuries. Al- though knowledge on the subject of radial head fractures and their associated injuries has increased over the past years, the opti mal treatment for Mason type II and III fractures is sti ll uncertain. The vast majority of the evidence is based on retrospecti ve case series and only a handful of prospecti ve studies are available.77 There is a strong need for standardizing fracture classifi cati on and clinician based and pati ent reported outcome measures, in order to make results of treatment comparable. The Broberg and Morrey adaptati on of the Mason classifi cati on is preferred by the authors, as it is widely used, provides a clear defi niti on of displacement and arti cular surface, and the intra- and inter-observer agreement is bett er, compared to other classifi cati ons.11, 13, 15 With current knowledge, we can state that the best available guideline for treatment of radial head fractures is that Mason type I fractures are stable and can be treated conservati vely, Mason type II fractures with > 2mm dislocati on and > 30% of the arti cular surface are usually unstable and can best be treated with ORIF with good results. Mason type III fractures with ≤ 3 fragments can be treated with ORIF. In case of > 3 fragments prostheti c replacement is required. The role of radial head excision without prostheti c replacement is limited and contra-indicated in pati ents with associated injury.1 Concerning isolated Mason type II fractures with > 2 mm of dislocati on, there might be a greater role for conservati ve treatment.46, 49 Also there are reports available of sati sfactory results aft er ORIF of Mason type III fractures with > 3 fragments.44, 45 Treatment of radial head fractures therefore remains subject of discussion. There is a need for randomized clinical trials with suffi cient pati ent numbers. The treati ng physician should be aware of associated injuries and take them into account when treati ng pati ents 34 Chapter 2

with displaced and/or comminuted radial head fractures in order to achieve a functional and stable elbow joint.

COnCLuSIOnS

Radial head fractures are common injuries and are accompanied by clinically relevant associated injuries in over one third of the patients. Mason type I fractures can be treated conservatively. The optimal (surgical) treatment for Mason type II and III fractures is still uncertain. There is a strong need for randomized clinical trials, standardizing of fracture classification and clinician based and patient reported outcome measures, in order to make results of treatment reported in literature comparable. Management of radial head fractures 35

REFEREnCE LIST

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(41) Givissis PK, Symeonidis PD, Ditsios KT, Dionellis PS, Christodoulou AG. Late results of absorbable pin fi xati on in the treatment of radial head fractures. Clin Orthop Relat Res 2008 May; 466(5): 1217-24. (42) Helling HJ, Prokop A, Schmid HU, Nagel M, Lilienthal J, Rehm KE. Biodegradable implants versus standard metal fi xati on for displaced radial head fractures. A prospecti ve, randomized, multi center study. J Shoulder Elbow Surg 2006 Jul;15(4): 479-85. (43) Moore DR, Tanner SL, Jeray KJ. The use of minicondylar blade plates in the treatment of radial head and neck fractures. Orthopedics 2006 Nov;29(11): 974-7. 2 (44) Ikeda M, Sugiyama K, Kang C, Takagaki T, Oka Y. Comminuted fractures of the radial head. Compari- son of resecti on and internal fi xati on. J Bone Joint Surg Am 2005 Jan; 87(1): 76-84. (45) Businger A, Ruedi TP, Sommer C. On-table reconstructi on of comminuted fractures of the radial head. Injury 2009 Nov 20. (46) Lindenhovius AL, Felsch Q, Ring D, Kloen P. The long-term outcome of open reducti on and internal fi xati on of stable displaced isolated parti al arti cular fractures of the radial head. J Trauma 2009 Jul; 67(1):143-6. (47) Michels F, Pouliart N, Handelberg F. Arthroscopic management of Mason type 2 radial head fractures. Knee Surg Sports Traumatol Arthrosc 2007 Oct;15(10): 1244-50. (48) Rolla PR, Surace MF, Bini A, Pilato G. Arthroscopic treatment of fractures of the radial head. Arthros- copy 2006 Feb;22(2): 233. (49) Akesson T, Herbertsson P, Josefsson PO, Hasserius R, Besjakov J, Karlsson MK. Primary nonoperati ve treatment of moderately displaced two-part fractures of the radial head. J Bone Joint Surg Am 2006 Sep;88(9): 1909-14. (50) Akesson T, Herbertsson P, Josefsson PO, Hasserius R, Besjakov J, Karlsson MK. Displaced fractures of the neck of the radius in adults. An excellent long-term outcome. J Bone Joint Surg Br 2006 May; 88(5):642-4. (51) Broberg MA, Morrey BF. Results of delayed excision of the radial head aft er fracture. J Bone Joint Surg Am 1986 Jun;68(5): 669-74. (52) Herbertsson P, Josefsson PO, Hasserius R, Besjakov J, Nyqvist F, Karlsson MK. Fractures of the radial head and neck treated with radial head excision. J Bone Joint Surg Am 2004 Sep;86-A(9): 1925-30. (53) Chapman CB, Su BW, Sinicropi SM, Bruno R, Strauch RJ, Rosenwasser MP. Vitallium radial head prosthesis for acute and chronic elbow fractures and fracture-dislocati ons involving the radial head. J Shoulder Elbow Surg 2006 Jul;15(4): 463-73. (54) Nalbantoglu U, Kocaoglu B, Gereli A, Aktas S, Guven O. Open reducti on and internal fi xati on of Mason type III radial head fractures with and without an associated elbow dislocati on. J Hand Surg Am 2007 Dec;32(10): 1560-8. (55) Ring D. Open reducti on and internal fi xati on of fractures of the radial head. Hand Clin 2004 Nov; 20(4):415-27, vi. (56) Doornberg JN, Parisien R, van Duijn PJ, Ring D. Radial head arthroplasty with a modular metal spacer to treat acute traumati c elbow instability. J Bone Joint Surg Am 2007 May; 89(5): 1075-80. (57) Harrington IJ, Sekyi-Otu A, Barrington TW, Evans DC, Tuli V. The functi onal outcome with metallic radial head implants in the treatment of unstable elbow fractures: a long-term review. J Trauma 2001 Jan;50(1): 46-52. (58) Judet T, Garreau de LC, Piriou P, Charnley G. A fl oati ng prosthesis for radial-head fractures. J Bone Joint Surg Br 1996 Mar;78(2): 244-9. (59) Stuff mann E, Baratz ME. Radial head implant arthroplasty. J Hand Surg Am 2009 Apr; 34(4): 745-54. (60) Moungondo F, El KW, Van RR, Feipel V, Rooze M, Schuind F. Radiocapitellar joint contacts aft er bipolar radial head arthroplasty. J Shoulder Elbow Surg 2009 Dec 24. 38 Chapter 2

(61) Moon JG, Berglund LJ, Zachary D, An KN, O’Driscoll SW. Radiocapitellar joint stability with bipolar versus monopolar radial head prostheses. J Shoulder Elbow Surg 2009 Sep; 18(5): 779-84. (62) Doornberg JN, Parisien R, van Duijn PJ, Ring D. Radial head arthroplasty with a modular metal spacer to treat acute traumatic elbow instability. J Bone Joint Surg Am 2007 May; 89(5): 1075-80. (63) Popovic N, Lemaire R, Georis P, Gillet P. Midterm results with a bipolar radial head prosthesis: radiographic evidence of loosening at the bone-cement interface. J Bone Joint Surg Am 2007 Nov; 89(11): 2469-76. (64) Moro JK, Werier J, MacDermid JC, Patterson SD, King GJ. Arthroplasty with a metal radial head for unreconstructible fractures of the radial head. J Bone Joint Surg Am 2001 Aug; 83-A(8): 1201-11. (65) Grewal R, MacDermid JC, Faber KJ, Drosdowech DS, King GJ. Comminuted radial head fractures treated with a modular metallic radial head arthroplasty. Study of outcomes. J Bone Joint Surg Am 2006 Oct; 88(10): 2192-200. (66) O’Driscoll SW, Herald J. Symptomatic failure of snap-on bipolar radial head prosthesis. J Shoulder Elbow Surg 2009 Sep; 18(5): e7-11. (67) Burkhart KJ, Mattyasovszky SG, Runkel M, Schwarz C, Kuchle R, Hessmann MH, et al. Mid- to long- term results after bipolar radial head arthroplasty. J Shoulder Elbow Surg 2010 Oct; 19(7): 965-72. (68) Ruan HJ, Fan CY, Liu JJ, Zeng BF. A comparative study of internal fixation and prosthesis replacement for radial head fractures of Mason type III. Int Orthop 2009 Feb; 33(1): 249-53. (69) Janssen RP, Vegter J. Resection of the radial head after Mason type-III fractures of the elbow: follow-up at 16 to 30 years. J Bone Joint Surg Br 1998 Mar; 80(2): 231-3. (70) Stoffelen DV, Holdsworth BJ. Excision or Silastic replacement for comminuted radial head fractures. A long-term follow-up. Acta Orthop Belg 1994; 60(4): 402-7. (71) Coleman DA, Blair WF, Shurr D. Resection of the radial head for fracture of the radial head. Long- term follow-up of seventeen cases. J Bone Joint Surg Am 1987 Mar; 69(3): 385-92. (72) Antuna SA, Sanchez-Marquez JM, Barco R. Long-term results of radial head resection following isolated radial head fractures in patients younger than forty years old. J Bone Joint Surg Am 2010 Mar; 92(3): 558-66. (73) Sanchez-Sotelo J, Romanillos O, Garay EG. Results of acute excision of the radial head in elbow radial head fracture-dislocations. J Orthop Trauma 2000 Jun; 14(5): 354-8. (74) van Riet RP, An KN. Biomechanics of the elbow. In: Eygendaal D, editor. The Elbow. 1 ed. Nieuwe- gein: Arko Sports Media; 2009. p. 27-34. (75) Beingessner DM, Dunning CE, Gordon KD, Johnson JA, King GJ. The effect of radial head excision and arthroplasty on elbow kinematics and stability. J Bone Joint Surg Am 2004 Aug; 86-A(8): 1730-9. (76) Ikeda M, Oka Y. Function after early radial head resection for fracture: a retrospective evaluation of 15 patients followed for 3-18 years. Acta Orthop Scand 2000 Apr; 71(2): 191-4. (77) Struijs PA, Smit G, Steller EP. Radial head fractures: effectiveness of conservative treatment versus surgical intervention. A systematic review. Arch Orthop Trauma Surg 2007 Feb; 127(2): 125-30. Part II Epidemiology and osteoporosis

Chapter 3 The epidemiology of radial head fractures

Laurens Kaas, Roger P. van Riet, Jos P.A.M. Vroemen, Denise Eygendaal.

Journal of Shoulder and Elbow Surgery 2010; 19(4):520-3. 42 Chapter 3

AbSTRACT

Background: Recent literature shows an increased mean age of female patients with radial head fractures compared with male patients with radial head fractures. However, data on epidemiology of radial head fractures and specifically in relation to age distribution and male-female ratios of radial head fracture, are scarce. Methods: A retrospective database search was performed to identify all patients with a radial head fracture over a 3-year period. Results: A total of 328 radial head fractures were diagnosed in 322 patients. The incidence was 2.8 per 10.000 inhabitants per year. The male-female ratio was 2:3. The average age was 48.0 years (range: 14–88, SD 14.8). The average age of female patients (52.8 years) was significantly higher than male patients (40.5 years) (p = 0.001). As the age increases above 50 years, the number of female patients becomes significantly higher than male patients (p = 0.001). An associated injury occurred in 40 patients (12.4%). Con- clusions: Radial head fractures are common and associated injuries are frequent. Epidemiology of radial head fractures 43

InTRODuCTIOn

Radial head fractures are common and account for one third of all fractures of the elbow. They usually result from a fall on the outstretched arm with the elbow in pronati on and parti al fl exion.1 Radial head fractures can be classifi ed using the Mason-classifi cati on, which is based on a series of 100 pati ents. According to this classifi cati on, radial head fractures can be divided into three types: a type I fracture is a non-displaced fracture, a type II fracture is a displaced fracture and type III fractures are comminuted fractures.2 Johnston added a fourth type: a radial head fracture with dislocati on of the elbow (table 3 I).3 Because it has been shown that the outcome of radial head fractures is highly dependent on associated lesions recently, a Mayo Clinic adaptati on of the Mason classifi cati on (based on 333 cases4) was published in order to include these lesions.5 Historically, most fractures have been reported to occur between 20-60 years of age, with a mean age of 30 to 40 years.2, 6 Radial head fractures have also been reported to be more common in females than in males, with a rati o of 2:1.1 However, recent publicati ons provide a diff erent insight in the epidemiology of radial head fractures and its associated injuries. van Riet et al.4 and Kaas et al.7 found an average age of 45-45.9 years and that on average females are 7-16.8 years older than males. Male-female rati os are 2:3. The goal of this study is to examine the epidemiology of radial head fractures and specifi cally to describe age distributi on and male-female rati os of radial head fracture above the age of 50 years.

METHODS

A retrospecti ve database search was performed to identi fy all pati ents who presented with a radial head fracture on the emergency department of our hospital between January 1st 2006 and January 1st 2009. This level 2 trauma centre provides a region of 400.000 inhabitants with acute medical care and is annually visited by approximately 44.000 pati ents. Radiographs of the elbow were reviewed by two of the authors. Gender, age, side and associated osseous injury were documented. Radiographs of the ipsilateral upper extremity were also reviewed for associated injuries. Radial head fractures were classifi ed

Type Descripti on I Non-displaced fracture II Minimal displacement with angulati on or impression III Comminuted fracture with dislocati on IV Radial head fracture with dislocati on of the elbow Table I: The Mason-Johnston classifi cati on of radial head fractures.2 44 Chapter 3

according to the Mason-Johnston classification (table I) and coronoid fractures according to the Regan and Morrey classification (table II).8 The statistical analysis was performed by a biostatician. A Chi-square test was used to statistically analyse differences between genders for: types of fractures, over or under 50 years of age and associated lesions. This test was also used to analyse differences between Mason types for average age and associated injuries. The analysis of variance test was performed to determine significant difference in age for Mason type and gender. A paired t-test was performed to determine the significance of the difference of average age between patients with or without associated injuries. A p-value ≤ 0.05 was considered statistically significant.

RESuLTS

In the selected three-year period, a total of 322 patients, with a mean age was 47.9 years (range: 14–88 years, SD: 16.7), were diagnosed with a total of 328 radial head fractures.

Type Description I Avulsion fracture the coronoid process II Fracture of <50% of the coronoid process III Fracture of >50% of the coronoid process Table II: The Regan and Morrey classification of coronoid fractures.8

30 Number Number of patients

0 0-19 20-29 30-39 40-49 50-59 60-69 70-79 80-99 Age group (in years)

Figure 1: Age distribution of the patients with a radial head fracture (left = total, middle = male, right = female). Epidemiology of radial head fractures 45

The esti mated incidence was 2.8 per 10.000 inhabitants per year. The male-female rati o was 2:3, with 126 male pati ents (39.1%) and 196 female pati ents (60.9%), which represents a signifi cant diff erence in gender (p = 0.001). In 122 pati ents (37.9%) the radial head fracture was on the right side, and 194 pati ents (60.2%) had a radial head fracture on the left . In additi on, 6 pati ents (1.9%) had bilateral radial head fractures. The mean age of female pati ents was 52.8 years (range: 14–88 years, SD: 16.3), which is signifi cantly older (p = 0.001) than the mean age of male pati ents, which was40.5 years (range: 16-76 years, SD: 14.4). The peak incidence of radial head fractures in female pati ents was between 50 and 59 years of age, compared to the peak incidence between 3 30 and 39 years in male pati ents (fi gure 1). There was no stati sti cal diff erence (p = 0.65) between the number of male pati ents and female pati ents below the age of 50 years. However, as the age rises above the age of 50 years, there were signifi cantly more female pati ents (n = 120) than male pati ents (n = 36) (p = 0.001). A Mason type I fracture was seen in 207 pati ents (64.3%), with a mean age of 45.9 years (SD: 14.8). A Mason type II fracture was diagnosed in 69 pati ents (21.4%), with a mean age of 52.3 years (SD: 15.0). A Mason type III fracture was found in 38 pati ents (11.8%) (mean age: 50.2 years, SD :18.8), and 8 pati ents (2.5%) with a mean age of 54.0 years (SD 9.2), had an associated elbow dislocati on. There was no stati sti cal signifi cant diff erence in age and gender between the Mason-types (p = 0.99). Of the 322 pati ents, 40 (12.4%) presented with some sort of associated osseous injury on the emergency department (fi gure 2). Coronoid fractures were most common. Of the

Figure 2: A lateral elbow view of a 35 year-old male with a Mason-Hotchkiss type 3 radial head fracture (arrow R) with posterior dislocati on of the elbow, a displaced olecranon fracture (arrow O) and a Regan- Morrey type 1 fracture of the coronoid (arrow C). 46 Chapter 3

Associated injury Number of patients % of total % of fractures Coronoid fracture 19 5.9 47.5 Scaphoid fracture 9 2.8 22.5 Capitellar fracture 5 1.6 12.5 Proximal ulna fracture 4 1.2 10 Avulsion fracture LCL 2 0.6 5 Avulsion fracture MCL 1 0.3 2.5 Essex-Lopresti injury 1 0.3 2.5 Subcapital humeral fracture 1 0.3 2.5 Radial head dislocation 1 0.3 2.5 Total 40 12.4 100 Table III: Associated osseous injuries with radial head fractures.

Mason Average age Males Females Number of patients with associated fractures type (years) I 45.9 77 130 15 (7.2%) II 52.3 25 44 6 (8.7%) III 50.2 20 18 14 (36.8%) IV 54.0 3 5 5 (62.5%) Total 47.9 125 197 40 (12.4%) Table IV: Patient characteristics of each different Mason-type group.

19 patients (5.9%) with this type of injury, 16 presented with a Regan and Morrey type I coronoid fracture and 3 patients had a type II fracture. Scaphoid fractures were seen in 9 patients (2.8%) and capitellar fractures in 5 patients (1.6%). Fractures of the proximal ulna or olecranon were diagnosed in 4 patients (1.2%). Distal radial fractures or an avulsion fracture of the lateral collateral ligament were seen in 2 patients each (1.2%). An Essex- Lopresti injury, triquetral fracture, avulsion fracture of the medial collateral ligament and a dislocation of the radial head were each seen in 1 patient (0.3%) (table III). Associated osseous injuries were present in 15 patients (7.2%) with a Mason type I and 6 patients (8.7%) with a type II fracture. 36.8% (n = 14) of the patients with a Mason type III fracture and 62.5% (n = 5) with a type IV fracture had associated fractures (table IV). The difference between the incidence of associated osseous injuries and Mason types were significant (p = 0.001). The mean age of patients with associated injuries did not differ significantly compared to the patients without associated injuries (p = 0.18). There was also no statistical significant difference between the number of male patients (n = 16) and females patients (n = 24) with associated injuries (p = 0.99). Epidemiology of radial head fractures 47

DISCuSSIOn

The results found in this study are similar to those in a previous study, published by our study group in 2008: a retrospecti ve study that consisted of a series of 147 pati ents.7 The esti mated incidence was 2.5 per 10,000 per year, compared with 2.8 per 10,000 per year in the current study. The mean age of the pati ents was similar as well: 45.9 compared to 47.9 years old.7 The mean age increases from 30 to 40 years in the earlier literature, to 47.9 years.1, 7 This is a similar increase to that reported in a previous retrospecti ve study of 333 pati ents.4 3 In literature, male-female rati os vary between 1:1 and 3:2.2, 6, 9 However, the more recent publicati ons show male-female rati os of 2:3, with female pati ents being signifi cantly older than male pati ents (37-41 years vs 48-54 years).4, 7 The current study confi rms a peak incidence in men between the age of 30 and 40 and in women between 50 and 60 years.4 The number of female pati ents with a radial head fracture is signifi cantly larger than male pati ents as the age rises above 50. Under the age of 39, male pati ents are more commonly aff ected by this injury, but this diff erence is not signifi cant. These fi ndings might suggest a possible link between radial head fractures and osteoporosis. The correlati on between radial head fractures and osteoporosis has to be further investi gated. If a strong correlati on could been established, females above the age of 50 should be off ered screening for osteoporosis in order to prevent other osteoporoti c fractures. The incidence of associated osseous injury is similar to that found earlier by our study group in 2008: 10.2% versus 12.4% found in this study.7 It is interesti ng that in a study by van Riet et al.4, associated fractures were described in 23%, but this diff erence may be due to the fact that the study was conducted in a referral practi ce, and showed a relati vely higher incidence of Mason type 3 fractures (19.6% compared with 11.8%). In both studies coronoid fractures were most the commonly associated osseous injury, followed by scaphoid fractures. No signifi cant diff erence in age was found in this study between pati ents with or without associated injuries, so a possible relati onship of associated osseous injuries and osteoporosis is not likely. Recent literature shows the clinical importance of these associated injuries, so the treati ng physician should be aware of these injuries when treati ng pati ents with a radial head fracture.6, 10-12

COnCLuSIOnS

A radial head fracture is a common injury, frequently accompanied by associated osseous injuries. On average, female pati ents are signifi cantly older than male pati ents, witha signifi cant increase in incidence as the age rises above 50 years. A possible correlati on between radial head fractures and osteoporosis has to be further investi gated. 48 Chapter 3

REFEREnCE LIST

Laurens Kaas, Inger N. Sierevelt, Jos P.A.M. Vroemen, C. Niek van Dijk, Denise Eygendaal

Submitted 50 Chapter 4

AbSTRACT

Introduction: Identifying radial head fractures as fragility fractures may improve case- finding for osteoporosis and thus be an indicator other fragility fractures. Methods: 35 female patients of ≥50 years of age with a radial head fracture and 57 controls were retrospectively selected and matched for age in strata of 5 years. Peripheral bone density measurement (BMD) was performed at the calcaneus. A T-score of <-2.7 was considered osteoporosis. In case of a T-value between -1.4 and -2.7, an additional dual energy X- ray (DXA) scan was performed. Results: The median age of the patients was 60 years, compared to 58 years of the control patients (P = 0.33). The mean T-score of the patients was -1.8 (range: -2.2 to -0.3, SD: 1.0), compared to -1.2 (range: -4.0 to 1.3, SD: 1.2) for the control patients (P = 0.04). 11 patients and 5 control patients were diagnosed with osteoporosis. The patients had an increased risk of osteoporosis compared to the control patients, with an odds ratio (OR) of 3.4, with a P-value of 0.027. Conclusions: This study confirms that radial head fractures in female patients ≥50 years are potential osteoporotic fractures. Offering these patients a BMD measurement may prevent future osteoporotic fractures, such as hip and spine fractures. Level of evidence: Level III. Radial head fractures and osteoporosis 51

InTRODuCTIOn

Radial head fractures are common, with an incidence of 2.5-2.9 per 10.000 inhabitants per year and account for up to one third of all elbow fractures.1, 2 The pati ents mean age is 45-48 years old, with a male to female rati o ranging from 1:1 to 2:3.2, 3 Women are signifi - cantly older (53-57 years) compared to men (34 to 41 years) when suff ering a radial head fracture. Peak incidence in male pati ents is between the age of 30 to 40 and in females between 50 to 60 years.2, 4 The number of female pati ents with a radial head fracture is signifi cantly larger than males as the age rises above 50 years. Gebauer et al. studied 60 radial heads from cadavers and found osteoporoti c changes in the micro-architecture, in both males and females, which can imply that radial head fractures are at least parti al osteoporoti c fractures.2, 5 These observati ons suggest a possible correlati on between radial 4 head fractures and osteoporosis. Identi fying radial head fractures as fragility fractures may improve case-fi nding for osteoporosis and thus be an indicator of other fragility fractures, as radial head fractures occur earlier in life, compared to hip and vertebral fractures.6 The hypothesis of this retrospecti ve case-control study is that there is an increased incidence of osteoporosis in female pati ents ≥50 years of age with a radial head fracture compared to control pati ents without a radial head fracture.

PATIEnTS AnD METHODS

Pati ents The study cases in this retrospecti ve non-randomized case-control study were female pati ents of ≥50 years of age, who visited the emergency department of the Amphia hospital (Breda, the Netherlands) with a radiographically visible radial head fracture in the period between January 1st and December 31st 2009 were retrospecti vely reviewed. According to the current protocol for screening on osteoporosis by the Dutch Orthopaedic Federati on, these pati ents were off ered a standard osteoporosis screening with a bone mineral density (BMD) measurement at our fracture and osteoporosis (FO) clinic aft er initi al fracture treatment.7 Control subjects were selected from the medical records of female pati ents, ≥50 years, who underwent a BMD measurement, which was off ered to visitors of the open door day of our hospital for the general public. Pati ents with recent fractures (<12 months), immobility, dementi a and bone disorders other than osteoporosis were excluded. Control pati ents were matched for gender (all female) and age (within 5 years) with the cases. At least one control pati ents was matched to each case and some cases had two controls. All control pati ents underwent a BMD assessment. A specialized nurse practi ti oner at the FO clinic collected all pati ent’s data, such as length, weight, BMI and period between menopause and radial head fracture. Additi onal risk factors for os- 52 Chapter 4

teoporosis, such as smoking behaviour, corticosteroid use, previous osteoporotic fractures and a body weight of >60 kg, were collected.

bMD measurement The BMD was measured using dual energy X-ray (DXA) and laser absorptiometry of the non-dominant calcaneus with the DXL Calscan (Demetech AB, Solna, Sweden). This peripheral BMD measuring device combines dual energy X-ray absorptiometry with laser absorptiometry. The laser absorptiometry corrects for the soft tissue component of the heel, which results in 10-20% more accuracy compared to other peripheral DXA technol- ogy. Several studies have shown that this method can be used in the measurement of BMD.8-10 A T-score of >-1.4 measured with the DXL Calscan was considered as normal, indicating normal bone density. A T-score with the DXL Calscan of <-2.7 was considered as abnormal and proof of osteoporosis. A T-score between -1.4 and -2.7 was considered as indication of osteopenia. In these cases an additional DXA scan of the femoral neck was performed, which is regarded as the gold standard.11 The T-score of the DXA scan was considered as the final result for these patients. Reference values of the DXA scan interpreted were according to the World Health Organisation (WHO): A patient was classified as being osteoporotic if the T-score was below –2.5.12

Statistical analysis Due to skewed distributions data are presented as medians with accompanying ranges. The Mann-Whitney test was used to compare baseline characteristics such as age, Length, weight and time interval between menopause and BMD assessment. The Cox regression model was used to perform a matched logistic regression analysis to determine the effect of osteoporosis on radial head fractures. Cases and controls were stratified in age groups of 5 years and odds ratios with 95% confidence intervals were calculated. A p-value of 0.05 was considered as statistically significant. Analysis was performed using SPSS for Windows version 16 (SPSS Inc., Chicago, IL, USA).

RESuLTS

In the selected period, patients with a radial head fracture who met the inclusion criteria were identified. They were offered a standard osteoporosis screening with a BMD measurement at our FO clinic after initial fracture treatment. Of these 47 patients, 35 accepted the protocol and were screened, with a median age of 60 (50-84) years. The mean time between the radial head fracture and the BMD measurement was 6.8 (2-12) months. A total number of 57 controls were included, with a median age of 60 (50-84) years. All cases and controls were Caucasian. Except for the period between menopause and BMD assessment Radial head fractures and osteoporosis 53

Cases (n=35) Controls (n=58) P-value Age (years) Median 60 58 0.33 Range 51-84 50-84 Period menopause-scan Median 11 8 0.05 (years) Range 0-40 0-36 Length (m) Median 1.66 1.65 0.97 Range 1.48-1.80 1.53-1.80 Weight (kg) Median 69 68 0.54 Range 49-100 45-110 BMI (kg/cm2) Median 25.2 24.1 0.39 Range 19.1-36.4 18.5-38.7 Table I: Baseline data of cases and controls. 4 (a median of 11 years of the cases vs. a median of 8 years in the control group), there were no signifi cant diff erences between the case- and control-groups. Pati ent characteristi cs are summarized in table I. A total of 23 pati ents (14 cases and 9 controls), had a t-score of between -1.4 and -2.7 with the DXL Calscan and underwent an additi onal DXA scan to determine a fi nal T-score. The mean T-score of the fracture cases was -1.8 (range: -2.2 to -0.3, SD: 1.0), compared to -1.2 (range: -4.0 to 1.3, SD: 1.2) for the control group (p = 0.04). 11 fracture cases and 5 controls were diagnosed with osteoporosis (p = 0.01). The cases had an increased risk of osteoporosis compared to the controls, with an Odds Rati o (OR) of 3.4 (95% Confi dence Interval (CI); 1.1-10.1), with a p-value of 0.03.

DISCuSSIOn

The results of this study support the hypothesis that radial head fractures in women ≥50 years old are to be considered as osteoporoti c fractures. This could also explain the typical age distributi on of pati ents with a radial head fracture.2, 4 This hypothesis is also supported by the osteoporoti c anatomical changes found in 30 cadaveric radial heads of elderly human specimens by Gebauer et al.5: histomorphometry revealed a signifi cant reducti on of corti cal thickness, bone volume per ti ssue volume, and trabecular thickness in male and female specimens. A signifi cant decrease of total and corti cal bone mineral density was also observed. Identi fying and treati ng female pati ents ≥50 years with a radial head fracture as pati ents with a high risk of osteoporosis, may prevent future fragility fractures such as hip and vertebral fractures, as they occur later in life compared to radial head fractures.6 However, the OR for osteoporosis is lower compared to distal radial fractures: 7.1 vs. 3.4 in this study.13 This diff erence can be explained by the anatomy of the proximal and distal radius. The process of demineralizati on in osteoporosis is more manifest in the 54 Chapter 4

cancellous bone and compared to the proximal radius, the distal radius consists of more cancellous bone in relationship to the amount of cortical bone.14 The DXL Calscan has been introduced as a novel (screening) method to assess BMD. The main advantages are that the device is patient-friendly, easy to use, with a relatively short examination time.15, 16 The DXL Calscan sensitivity (80% for osteoporosis and 82% for osteopenia) and specificity (82% for osteoporosis and 89% for osteopenia) is reported to be reasonably high and reproducibility is good.17 To increase sensitivity and specificity of the DXL Calscan, the thresholds were set at T-score of >-1.4 for manifest non-osteoporotic and <-2.7 for manifest osteoporosis, according to guideline of the United Kingdom National Osteoprosis Society.18 These thresholds are defined so that patients with osteoporosis at the hip or spine are identified with 90% sensitivity and 90% specificity. Patients with a DXL Calscan result below the lower threshold are likely to have osteoporosis at the hip or spine, patients with a result above the upper threshold are unlikely to have osteoporosis, while those between the two thresholds require a hip and spine BMD examination for a definitive diagnosis. A weakness of this study is the possible bias of a significant difference in the mean period between start of the menopause and BMD: 15.5 years in patients with a radial head fracture, compared to 10.5 years in the control patients. This bias might underestimate the incidence of osteoporosis in the control group.

COnCLuSIOnS

In conclusion we can state that this is, to our knowledge, the first case-control study that links radial head fractures to an increased risk for osteoporosis in female patients of ≥50 years of age. Identifying radial head fractures in these patients as potential osteoporotic fractures and offering a BMD measurement improves the early diagnosis of osteoporosis. Subsequent and adequate treatment of osteoporosis may then prevent future osteoporotic fractures, such as hip and spine fractures. Radial head fractures and osteoporosis 55

REFEREnCE LIST

(1) Herbertsson P, Josefsson PO, Hasserius R, Karlsson C, Besjakov J, Karlsson M. Uncomplicated Mason type-II and III fractures of the radial head and neck in adults. A long-term follow-up study. J Bone Joint Surg Am 2004 Mar;86-A(3): 569-74. (2) Kaas L, van Riet RP, Vroemen J, Eygendaal D. The epidemiology of radial head fractures. J Shoulder Elbow Surg 2010 Jun 1;19(4): 520-3. (3) van Riet RP, Morrey BF, O’Driscoll SW, van Glabbeek F. Associated injuries complicati ng radial head fractures: a demographic study. Clin Orthop Relat Res 2005;441: 351-5. (4) Gebauer M, Rucker AH, Barvencik F, Rueger JM. [Therapy for radial head fractures]. Unfallchirurg 2005 Aug;108(8): 657-67. (5) Gebauer M, Barvencik F, Mumme M, Beil FT, Vett orazzi E, Rueger JM, et al. Microarchitecture of the Radial Head and Its Changes in Aging. Calcif Tissue Int 2009 Nov 13. (6) Mallmin H, Ljunghall S, Persson I, Naessen T, Krusemo UB, Bergstrom R. Fracture of the distal 4 forearm as a forecaster of subsequent hip fracture: a populati on-based cohort study with 24 years of follow-up. Calcif Tissue Int 1993 Apr;52(4): 269-72. (7) Kwaliteitsinsti tuut voor de Gezondheidszorg CBO. Osteoporose, Tweede herziene richtlijn. 2010. (8) Kullenberg R, Falch JA. Prevalence of osteoporosis using bone mineral measurements at the calcaneus by dual X-ray and laser (DXL). Osteoporos Int 2003 Oct;14(10): 823-7. (9) Hakulinen MA, Saarakkala S, Toyras J, Kroger H, Jurvelin JS. Dual energy x-ray laser measurement of calcaneal bone mineral density. Phys Med Biol 2003 Jun 21;48(12): 1741-52. (10) de Klerk G, van der Velde V, van der Palen J, van Bergeijk L, Hegeman JH. The usefulness of dual energy X-ray and laser absorpti ometry of the calcaneus versus dual energy X-ray absorpti ometry of hip and spine in diagnosing manifest osteoporosis. Arch Orthop Trauma Surg 2009 Feb;129(2): 251-7. (11) Kanis JA, McCloskey EV, Johansson H, Oden A, Melton LJ, III, Khaltaev N. A reference standard for the descripti on of osteoporosis. Bone 2008 Mar; 42(3): 467-75. (12) Kanis JA. Assessment of fracture risk and its applicati on to screening for postmenopausal osteoporosis: synopsis of a WHO report. WHO Study Group. Osteoporos Int 1994 Nov;4(6): 368-81. (13) Oyen J, Brudvik C, Gjesdal CG, Tell GS, Lie SA, Hove LM. Osteoporosis as a risk factor for distal radial fractures: a case-control study. J Bone Joint Surg Am 2011 Feb;93(4): 348-56. (14) Bartl R, Frisch B. Pathogenesis of osteoporosis. In: Bartl R, Frisch B, editors. Osteoporosis: diagnosis, treatment and therapy. 2 ed. Berlin: Springer-Verlag; 2009. p. 29-37. (15) Kullenberg R. Reference database for dual X-ray and laser Calscan bone densitometer. J Clin Densi- tom 2003;6(4): 367-72. (16) Marti ni G, Valenti R, Gennari L, Salvadori S, Galli B, Nuti R. Dual X-ray and laser absorpti ometry of the calcaneus: comparison with quanti tati ve ultrasound and dual-energy X-ray absorpti ometry. J Clin Densitom 2004;7(3): 349-54. (17) Thorpe JA, Steel SA. The DXL Calscan heel densitometer: evaluati on and diagnosti c thresholds. Br J Radiol 2006 Apr;79(940): 336-41. (18) Blake GM, Chinn DJ, Steel SA, Patel R, Panayiotou E, Thorpe J, et al. A list of device-specifi c thresholds for the clinical interpretati on of peripheral x-ray absorpti ometry examinati ons. Osteoporos Int 2005 Dec;16(12): 2149-56.

Part III: Associated injuries of radial head fractures

Chapter 5 Magnetic resonance imaging findings in 46 elbows with a radial head fracture

Laurens Kaas, Jeroen L. Turkenburg, Roger P. van Riet, Jos P.A.M. Vroemen, Denise Eygendaal

Acta Orthopaedica 2010; 81(3): 373-6. 60 Chapter 5

AbSTRACT

Background and purpose: Radial head fractures are common, and may be associated with orther injuries of clinical importance. We present the results of a standard additional magnetic resonance imaging (MRI) scan for patients with a radial head fracture. Patients and methods: 44 patients (mean age: 47 years) with 46 radial head fractures underwent MRI. 17 elbows had a Mason type I fracture, 23 had a Mason type II fracture, and 6 elbows had a Mason type III fracture. Results: Associated injuries were found in 35 elbows: 28 elbows had a lateral collateral ligament lesion, 18 had capitellar injury, 1 elbow had a coronoid fracture and 1 elbow had medial collateral ligament injury. Interpretation: The incidence of associated injuries with radial head fractures with MRI was high. The clinical relevance should be investigated. Key words: Radial head fracture, associated injury, trauma, magnetic resonance imaging. MRI fi ndings in elbows with a radial head fracture 61

InTRODuCTIOn

Fractures of the head of the radius are common and account for approximately one- third of all fractures of the elbow. The outcome of undisplaced or minimally displaced radial head fractures is good.1 Radial head fractures are usually classifi ed according to the Mason-Hotchkiss classifi cati on into type I to III. A type I fracture is minimally displaced (< 2 mm), a fracture with > 2 mm dislocati on is a type II fracture and type III fractures are comminuted.2 Recent studies have revealed a high incidence of associated injuries of the ipsilateral upper extremity with radial head fractures.3-5 Ligamentous and chondral injuries especially may go undetected by conventi onal radiographs, but may be important for treatment.4, 6-8 To assess the incidence of these injuries, we included a MRI scan of the elbow for every pati ent with a radial head fracture and now we present the fi ndings of the fi rst 46 elbows. 5 PATIEnTS AnD METHODS

44 pati ents (mean age: 45 (range: 20-75) years, 19 males and 25 females) with 46 radial head fractures who presented with a radial head fracture at our emergency department within 48 h aft er trauma, and who were available for follow-up in our hospital and, underwent an MRI scan of the elbow. 2 pati ents had bilateral radial head fractures and 26 fractures were on the dominant side. Anteroposterior and lateral conventi onal radiographs were evaluated for associated osseous injuries to the ipsilateral upper extremity. Additi onal images such as oblique views and shoulder or wrist images were obtained when indicated. An MRI scan of the injured elbow was done on a mean of 7 (range: 1-16) days aft er injury. 10 other pati ents did not receive an MRI scan as the ti ming of it would adversely delay the treatment of the injury. 5 pati ents had a Mason type II fracture (including 1 pati ent with a Monteggia lesion) and 5 pati ents with a Mason type III fracture (including 1 pati ent with an olecranon fracture and posterior dislocati on, 1 pati ent with an olecranon fracture and a type III coronoid fracture aft er a posterior dislocati on and 1 pati ent with a coronoid fracture and posterior dislocati on). MR imaging was performed with a 1.5 Tesla scanner with a dedicated small fl ex coil. Pati ents were imaged in the supine positi on with his or her arm overhead andthe forearm supinate. Imaging began about 10 cm above the elbow joint and extended to the bicipital tuberosity. Images were acquired in the axial, coronal, and sagitt al planes. Imaging comprised axial and coronal T1-weighted spin-echo (TR range/TE, 400-480/14) coronal fat-suppressed proton density-weighted fast spin-echo (TR/TE, 3500/30), coronal T2*-weighted gradient echo (TR/TE, 540/10) and sagitt al T2-weighted fast-recovery fast spin-echo (TR/TE, 6000/67) sequences. The T1-weighted sequences were obtained with 62 Chapter 5

the following parameters: 12 to 14 cm field of view, 256 x 192 image matrix, and 3.2 mm section thickness with a 0.3 to 0.5 mm intersection gap. The T2*-weighted sequence was obtained with the following parameters: 12 cm field of view, 256 x 192 image matrix, and 3.2 mm section thickness with a 0.3 mm intersection gap. The T2-weighted sequence was obtained with the following parameters: 12 cm field of view, 256 x 192 image matrix, and 3 mm section thickness with a 0.3 mm intersection gap. 2 signals were acquired for all sequences. The quality of the MRI was good in all but 2 elbows, where evaluation was difficult because of movement artefacts. The MRI scans and radiographs were evaluated by 1 of 2 experienced radiologists using a standardized scoring list. Osseous, chondral and ligamentous injury or dislocation of the ipsilateral upper extremity in combination with a radial head fracture were regarded as an associated injury. Specific attention was given to: loose bodies, bone bruising or fracture, osteochondral damage, injury to the lateral collateral ligament (LCL) complex, common extensor tendon, medial collateral ligament (MCL) complex, common flexor tendon and injury of the biceps and triceps tendon. Ligamentous injuries were divided into 4 subtypes: distortion (edema of the ligament, but no signs of rupture), partial rupture, complete rupture, and avulsion fracture. The Regan and Morrey classification9 was used for the classification of coronoid fractures. A type I fracture is an avulsion fracture, a type II fracture consists of < 50% of the coronoid height and a type III fracture of > 50% of the coronoid height. In case of doubt when analysing the MR images the final decision was made by a single musculoskeletal radiologist (JT).

RESuLTS

On conventional radiographs, a Mason type I fracture was found in 17 elbows, a Mason type II fracture in 23 elbows, and a Mason type III fracture in 6 elbows. 2 patients, both with a Mason type-III fracture, presented with a posterior dislocation of the elbow. With MRI, 2 elbows with a Mason type II fracture, were classified as a Mason type I fracture. Associated osseous injury on conventional radiographs was diagnosed in 3 elbows: 1 fracture of the coronoid process, 1 scaphoid fracture and 1 avulsion fracture of the lateral epicondyle. In 35 of the 46 elbows additional concomitant injuries were diagnosed with MR imaging of the elbow (table I). 11 of the 17 elbows with a Mason type I fracture had associated injury: 8 elbows had injury to the LCL, and 8 elbows had capitellar injury (figure 1). 17 of the 23 elbows with a type II fracture had associated injury: 15 elbows had LCL injury, and 8 elbows had capitellar injury. 2 elbows had a loose body and one elbow had bone bruising of the lateral epicondyle. All 6 elbows with a Mason type III suffered associated injuries: 5 elbows had LCL injury and 1 elbow had a rupture of the MCL. There was no MRI fi ndings in elbows with a radial head fracture 63

ABCDEFGHIJKLM 1 1 + 29 1 5 ------2* 1 - 28 1 4 - 1 3 - - - - 3 0 + 44 1 15 - - 1 - - - - 4 1 - 51 1 3 - 1 - - - - - 5 0 - 45 1 2 ------6 0 - 21 1 5 - - 1 - - - - 7 1 + 61 1 5 - 2 - - - - - 8 0 + 45 1 7 - 1 - - - - - 9 0 + 26 1 6 - - 1 - - - - 10 0 - 56 1 8 - 1 - - - - - 11 1 - 55 1 1 - 1 2 - - - - 12 0 + 42 1 3 ------13 0 + 52 1 5 - 1 2 - - - - 14 1 + 29 1 8 - 1 1 - - - - 15# 0 + 44 1 9 ------5 16 1 + 20 1 6 - - 1 - - - - 17 1 - 60 1 11 ------O 18 0 - 48 2 9 ------19 1 + 35 2 10 - 2 2 - - 1 - 20 0 - 45 2 10 - 2 - - - - - 21 0 + 53 2 16 - - 2 - - - - 22 1 + 53 2 10 - - 2 - - - - 23 0 + 75 2 6 - 2 3 - - - - 24 1 - 37 2 13 - 0 - - - - - 25 1 - 35 2 13 ------26 1 + 22 2 13 - 0 - - - - S 27 0 - 60 2 2 - 0 - - - - - 28 0 - 61 2 1 - 1 1 - - - - 29# 0 - 44 2 9 - 2 - - - 1 - 30 0 - 25 2 7 - 1 ----- 31 0 + 36 2 3 ------32 0 - 38 2 1 ------33 0 + 41 2 2 - 1 - - - - - 34 0 - 69 2 3 - 0 - - - - - 35* 1 + 28 2 4 ------36 1 + 59 2 8 - 1 - - - - - 37 1 + 37 2 16 - 0 2 - - - O 38 1 + 35 2 9 - - 1 - - - - 39 1 + 54 2 7 - 2 1 - - - - 40 0 - 34 2 4 ------64 Chapter 5

41 0 + 53 3 6 - 3 - - - - - 42 0 + 68 3 10 2 2 - - 1 - - 43 1 + 45 3 11 - 1 1 - - - M 44 0 + 51 3 4 - 1 - - 1 - Su 45 0 - 64 3 6 X X - 1 - - M 46 0 - 52 3 6 - 2 3 - - - - Table I: Details of all the elbows of the series. A = Number of subject B = Sex: 0 = female, 1 = male C = Dominant side D = Age (years) E = Mason-Hotchkiss type F = Number of days between trauma and MRI G = MCL lesion: 0 = contusion, 1 = partial, 2 = complete, 3 = avulsion fracture H = LCL lesion: 0 = contusion, 1 = partial, 2 = complete, 3 = avulsion fracture I = Capitellum: 1 = bone edema, 2 = chondral damage, 3 = fracture J = Coronoid fracture: 1 = type I, 2 = type II and 3 = type III (Regan and Morrey classification) K = Dislocation of the elbow joint L = Loose body M = Other: M = Movement artefacts, O = Oedema of the lateral epicondyle, S = scaphoid fracture, Su = elbow surgery. x = No reliable observation because of movement artefacts. * and # = bilateral fracture of the radial head in two patients

Figure 1: A MR-image of a full-thickness capitellar cartilage injury (black arrow) in an elbow with a Mason type 1 fracture (white arrow). MRI fi ndings in elbows with a radial head fracture 65

Associated injury Mason type I (n=17) II (n=23) III (n=6) LCL 8 15 6 MCL - - 1 Capitellar injury 8 8 2 Loose ostechondral fragment - 2 - Bone bruise lateral epicondyle - 1 - Coronoid fracture - - 1 Any type of associated injury 12 17 6 Table II: The number of elbows with a Mason type-I, type-II and type-III fracture with associated injuries on MR imaging. reliable observati on of ligamentous injuries because of movement artefacts occurred in 1 elbow with a Mason type III fracture. Osteochondral damage to the capitellum was seen in 2 elbows. 1 elbow with a Mason type III fracture had a coronoid fracture. 1 pati ent underwent surgery of the injured elbow: an open repositi on and internal fi xati on of the 5 comminuted fracture of the radial head and a refi xati on of the LCL. The fi ndings with the MRI scan were confi rmed during surgery - except for a complete tear of the LCL, which had been diagnosed as a parti al tear by MRI. (Table II)

DISCuSSIOn

Diagnosis of associated soft ti ssue injuries of the elbow with MR imaging can be diffi - cult, but ligamentous structures of the elbow can be evaluated with a good sensiti vity and specifi city.10-12 Inter-observer reliability of diagnosing LCL lesions with MRI is graded moderate to good.13 Mirowitz and London14 demonstrated a high correlati on between abnormaliti es of the MCL seen on MRI and pathologic fi ndings. Itamura et al.3 described a coeffi cient variati on less than 5% for intra-observer reliability. The F-test between two observers was not stati sti cally signifi cant for each MRI set.4 However, our study is limited as inter- and intra-observer reliability and the clinical relevance were not established. We found that MR imaging of pati ents with a radial head fracture revealed associated injuries in three-quarters of them, thus supporti ng recent studies on this subject. These injuries may be an explanati on for longstanding symptoms aft er an adequate treatment of radial head fracture.3, 4, 6 Early diagnosis of these injuries using MR imaging may contribute to a bett er understanding of the injuries of the pati ent with a radial head fracture, opti miz- ing (surgical) treatment and giving bett er outcome. The LCL typically ruptures as a result of external rotati onal forces and valgus moment under axial load aft er a fall on the outstretched hand. If the rotati onal forces conti nue, a dislocati on can fi nally occur, with or without rupture of the MCL. An elbow dislocati on can 66 Chapter 5

also occur without rupturing of the MCL.15 Because of the axial loading of the forearm the radiocapitellar joint is forcefully compressed. This explains the high incidence of associated capitellar injury. Fractures of the coronoid process are common in posterior (sub) luxations of the elbow, as the valgus force under axial load pushes the tip of the coronoid away against the trochlea. Hausman et al.16 found partial disruptions of the interosseous membrane in 9 of 14 patients with Mason type I radial head fractures using MRI. None of these disruptions were of clinical importance. As the entire forearm was not scanned in our study, we cannot draw any conclusions about injury to the interosseous membrane. 39% of the patients were reported to have concomitant fractures or clinically significant soft tissue injury in a large retrospective study of 333 adults with radial head fractures. LCL insufficiency occurred in 11%, MCL insufficiency in 2%. Combined lesions of the LCL and MCL occurred in 6%.4 Mason type I radial head fractures are likely to be stable fractures, without any ligamentous injury. Mason type II and type III radial head fractures are frequently associated with ligamentous injury and other fractures.4, 6, 17 We found LCL injury in 8 of 17 Mason type I fractures. Probably not all ligamentous lesions detected with MRI, are of clinical importance, i.e. ligamentous distorsion or partial lesions, where stability remains intact. The incidence of clinically relevant osteochondral lesions of the capitellum is reported to be 2% of all radial head fractures.4 In patients with a Mason type II and type III fractures who have undergone elbow surgery the incidence rises to 14 to 20%.3, 8, 18 Itamura et al.3 found osteochondral defects in one third of 24 patients with a Mason type II and type III fractures using MRI. We found osteochondral defects in 6 of 46 elbows. Osteochondral damage is possibly the least recognised associated injury in patients with a radial head fracture. Cartilagenous damage is usually not visible on conventional radiographs, but may cause persistent symptoms like crepitus and mechanical elbow locking. The incidence of associated injuries of the elbow with radial head fractures with MRI is high. The clinical importance of these associated injuries found with MRI has to be investigated. The treating physician should be aware of the associated injuries and has to take these into account when treating patients with radial head fractures. Persistent pain or other symptoms after a radial head fracture may have other causes than the fracture itself. MRI fi ndings in elbows with a radial head fracture 67

REFEREnCE LIST

(1) van Riet RP, van Glabbeek F, Morrey BF. Radial Head Fracture: General Considerati ons, Conservati ve Treatment and Open Reducti on and Internal Fixati on. In: Morrey B, Sanchez-Sotelo J, editors. The Elbow and its Disorders. 4 ed. Philadelphia: Saunders; 2009. p. 359-81. (2) Hotchkiss RN. Displaced fractures of the radial head: internal fi xati on or excision? J Am Acad orthop Surg 1997;5: 1-10. (3) Itamura J, Roidis N, Mirzayan R, Vaishnav S, Learch T, Shean C. Radial head fractures: MRI evaluati on of associated injuries. J Shoulder Elbow Surg 2005 Jul;14(4): 421-4. (4) van Riet RP, Morrey BF, O’Driscoll SW, van Glabbeek F. Associated injuries complicati ng radial head fractures: a demographic study. Clin Orthop Relat Res 2005;441: 351-5. (5) Kaas L, van Riet RP, Vroemen JP, Eygendaal D. The incidence of associated fractures of the upper limb in fractures of the radial head. Strategies Trauma Limb Reconstr 2008 Sep;3(2): 71-4. (6) Davidson PA, Moseley JB, Jr., Tullos HS. Radial head fracture. A potenti ally complex injury. Clin Orthop Relat Res 1993 Dec;(297): 224-30. (7) Steinmann SP. Coronoid process fracture. J Am Acad Orthop Surg 2008 Sep;16(9): 519-29. (8) Nalbantoglu U, Gereli A, Kocaoglu B, Aktas S, Turkmen M. Capitellar carti lage injuries concomitant with radial head fractures. J Hand Surg (Am) 2009;33(9): 1602-7. 5 (9) Regan W, Morrey BF. Fractures of the coronoid process of the ulna. J Bone Joint Surg 1989;71A: 1348-54. (10) Kaplan LJ, Pott er HG. MR imaging of ligament injuries to the elbow. Radiol Clin North Am 2006 Jul; 44(4):583-94, ix. (11) Pott er HG, Weiland AJ, Schatz JA, Palett a GA, Hotchkiss RN. Posterolateral rotatory instability of the elbow: usefulness of MR imaging in diagnosis. Radiology 1997 Jul;204(1): 185-9. (12) Hill NB, Jr., Bucchieri JS, Shon F, Miller TT, Rosenwasser MP. Magneti c resonance imaging of injury to the medial collateral ligament of the elbow: a cadaver model. J Shoulder Elbow Surg 2000 Sep; 9(5):418-22. (13) Carrino JA, Morrison WB, Zou KH, Steff en RT, Snearly WN, Murray PM. Lateral ulnar collateral ligament of the elbow: opti mizati on of evaluati on with two-dimensional MR imaging. Radiology 2001 Jan;218(1): 118-25. (14) Mirowitz SA, London SL. Ulnar collateral ligament injury in baseball pitchers: MR imaging evaluati on. Radiology 1992 Nov; 185(2): 573-6. (15) O’Driscoll SW, Jupiter JB, King GJ, Hotchkiss RN, Morrey BF. The unstable elbow. Instr Course Lect 2001;50: 89-102. (16) Hausmann JT, Vekszler G, Breitenseher M, Braunsteiner T, Vecsei V, Gabler C. Mason type-I radial head fractures and interosseous membrane lesions--a prospecti ve study. J Trauma 2009 Feb; 66(2): 457-61. (17) Doornberg J, Elsner A, Kloen P, Marti RK, van Dijk CN, Ring D. Apparently isolated parti al arti cular fractures of the radial head: prevalence and reliability of radiographically diagnosed displacement. J Shoulder Elbow Surg 2007 Sep;16(5): 603-8. (18) Michels F, Pouliart N, Handelberg F. Arthroscopic management of Mason type 2 radial head fractures. Knee Surg Sports Traumatol Arthrosc 2007 Oct;15(10): 1244-50.

Chapter 6 Magnetic resonance imaging in radial head fractures: Most injuries are not clinically relevant.

Laurens Kaas, Jeroen L. Turkenburg, Roger P. van Riet, Jos P.A.M. Vroemen, C. Niek van Dijk, Denise Eygendaal

Journal of Shoulder and Elbow Surgery 2011;20(8): 1282-8. 70 Chapter 6

AbSTRACT

Background: Recent studies report that magnetic resonance imaging (MRI) shows a high incidence of associated injuries in patients with a radial head fracture. This retrospective study describes the clinical relevance of these injuries. Methods: Forty patients with 42 radial head fractures underwent a MRI scan after a mean of 7.0 days after trauma and were reviewed after a mean of 13.3 months. Results: MRI showed 24 of 42 elbows had a lateral collateral (LCL) lesion, 1 had a medial collateral ligament (MCL) and LCL lesion, 16 had an injury of the capitellum, 1 had a coronoid fracture and 2 had loose osteochondral fragments. Clinical evaluation after a mean of 13.3 months showed that 3 elbows had clinical MCL or LCL laxity, of which 2 elbows had no ligamentous injuries diagnosed with MRI. One elbow with a loose osteochondral fragment showed infrequent elbow locking. The mean Mayo Elbow Performance Scale was 97.5 (range: 80-100) after a mean of 13.3 months after trauma, with no significant difference between patients with and without associated injuries (p = 0.8). Conclusion: Most injuries found with MRI in patients with radial head fractures are not symptomatic or of clinical importance in short term follow-up. Keywords: radial head fracture, elbow, trauma, magnetic resonance imaging, associated injuries. Level of evidence: IV. Clinical relevance of MRI fi ndings 71

InTRODuCTIOn

Radial head fractures are common, accounti ng for approximately one third of all fractures of the elbow and for 1.7 to 5.4% of all fractures in adults.1, 2 They usually are categorized according to the Mason-Hotchkiss classifi cati on in to type I to III: a type I indicates a fracture that is ≤ 2 mm displaced, a type II fracture is > 2 mm displaced, a type III fracture is a comminuted fracture of the enti re radial head.3 Radial head fractures are frequently accompanied with associated osseous, chondral and/or ligamentous injuries of the ipsilateral upper extremity.4-6 Ligamentous and chondral injuries remain commonly undetected by conventi onal radiographs, but may have consequences for treatment.2, 7-9 Recent studies using magneti c resonance imaging (MRI) show a 76-92% incidence of associated injuries in pati ents with a radial head fracture.4, 10 In a retrospecti ve study of 333 pati ents with a radial head fracture, clinically relevant associated fractures or soft -ti ssue injuries, or both, were diagnosed in 39% of the pati ents.5 Early diagnosis of these injuries using MRI might provide greater understanding of injuries of the pati ent with a radial head fracture, and opti mise (surgical) treatment and provide the pati ent with a bett er esti mate of their prognosis. The clinical relevance of concomitant injuries found with MRI is unclear. This retrospecti ve, observati onal study aims to describe the clinical relevance of associated injuries diagnosed with MRI in pati ents with a radial head fracture. 6

PATIEnTS AnD METHODS

A retrospecti ve evaluati on was conducted of 44 consecuti ve pati ents who presented with 46 radial head fractures in our emergency department (ED) within 48 hours aft er trauma. Radial head fractures were classifi ed using the Mason-Hotchkiss classifi cati on.3 Apart from conventi onal radiographs, these pati ents underwent a standard MRI scan to evaluate associated injuries of the aff ected elbow. The MRI scan was made at a mean of 7.0 (range: 1-16) days aft er injury and was performed with a 1.5 Tesla scanner (Signa, General Electric Medical Systems, Milwaukee, WI, USA) with a dedicated small fl ex coil. The dominant arm was aff ected in 21 of 42 elbows. 17 elbows had a Mason type I fracture on plain radiographs, 19 had a type II fracture and 6 had a type III fracture. 2 elbows, both with a type III fracture, had a posterolateral elbow dislocati on. Treatment was initi ated by the (orthopaedic) surgeon on call. MRI results were available for treati ng physician. 1 pati ent with a Mason type III fracture with posterolateral elbow dislocati on underwent surgical treatment: an open repositi on and internal fi xati on of the comminuted fracture of the radial head and a refi xati on of the LCL. All other pati ents were treated conservati vely. According to a standard protocol for follow-up of pati ents with a radial head fracture, 38 pati ents (86%) with 40 radial head fractures, who were a mean age of 46.1 years (range: 72 Chapter 6

Points Pain None 45 Mild 30 Moderate 15 Severe 0 Motion arc > 100 degrees 20 50-100 degrees 15 < 50 degrees 5 Stability Stable 10 Moderate instability 5 Gross instability 0 Daily function Comb hair 5 Feed self 5 Hygiene 5 Shirt 5 Shoe 5 Total Maximum 100 Table I: The Mayo Elbow Performance Score. A score > 90 is regarded as excellent, between 75-89 as good, between 60-74 as fair and < 60 is graded as poor.11

21-75 years), were reviewed after at least 12 months and were evaluated at a mean of 3.5 (range: 3-5) months and 13.3 (range: 12-19) months after trauma. Two patients did not attend the evaluation at 12 months, but were willing to answer questions by phone. These results were included in this study. Four patients (11%), all with a Mason type II fracture, were lost to follow-up. Presence of crepitus or hydrops, range of motion (flexion/extension and pronation/ supination using a standard goniometer), carrying angle, and stability of both elbows were assessed. Stability was classified into 3 types: type I: painful on palpation and stress but stable, type II: mild laxity, type III: gross laxity. Furthermore, the patients were questioned on the presence of wrist pain, the use of analgesics and resumption of work. Elbow function was scored using the Mayo Elbow Performance Score (MEPS) (table I).11 Radiographs of the elbow and wrist were obtained on indication. The MRI scans and radiographs were evaluated for associated pathology by one of two experienced radiologists. Ligamentous injuries of the lateral (LCL) and medial collateral ligament (MCL) were divided into four subtypes: distortion, partial rupture, complete rupture and avulsion fracture. The Regan and Morrey classification was used to classify coronoid fractures.12 A type I fracture is an avulsion fracture, a type II fracture consists of <50% of the coronoid height and a type III fracture of >50%. In case of doubt when analysing the MRI’s the final decision was made by a single musculoskeletal radiologist. Clinical relevance of MRI fi ndings 73

Type of associated injury Mason (N) I (17) II (19) III (6) Total (42) LCL Distorti on 0 4 0 4 Parti al rupture 7 3 2 12 Complete rupture 1 5 2 8 Avulsion fracture 0 0 1 1 Total 8 12 5 (%) 25 MCL Complete rupture 0 0 1 1 Capitellum Bone bruise 6 1 1 8 Chondral damage 2 3 0 5 Fracture 1 1 1 3 Total 9 5 2 16 Coronoid fracture 0 0 1 1 Loose body 0 2 0 2 Total 17 19 9 45 Table II: MRI fi ndings of the 42 elbows. N = number of pati ents per Mason group.

The quality of the MRI’s was excellent in all except 2 elbows, where evaluati on of the images was diffi cult because of moti on artefacts. Ten other pati ents which presented at the ED in the same period did not receive an 6 MRI scan as the ti ming of it would adversely delay the treatment of the injury. Associated injuries in these were assessed during surgery. In these pati ents, 5 had a Mason type II fracture (including 1 pati ent with a Monteggia lesion) and 5 pati ents had a Mason type III fracture, including 1 pati ent with an olecranon fracture and posterior dislocati on, 1 pati ent with an olecranon fracture and a type III coronoid fracture aft er a posterior dislocati on and 1 pati ent with a coronoid fracture and posterior dislocati on). This imaging delay was caused by several factors, such as inability to perform a MRI scan within 10 days aft er trauma or severity of the injury, in which delay of more than 1 day by performing the MRI before surgical treatment was unacceptable. These pati ents were not included in this study.

STATISTICAL METHODS

Because of a skewed distributi on, The Mann-Whitney test was used to compare functi onal results between pati ent groups with or without associated injuries. The Chi-square test was used to compare dichotomous variables between groups. SPSS 16.0 soft ware (SPSS, Chicago, Il) was used for stati sti cal analysis. 74 Chapter 6

MRI Results Clinical results

Patient characteristics ABCDEFGHIJKL MNOP 1 1 + 29 1 -/- - - - - 13 0/0/0/0 -/- - 100 100 2* 1 -- 28 1 -/1 3 - - - 14 5/0/0/0 -/- - 100 100 3 0 + 44 1 -/- 1 - - - 12 0/0/0/0 -/- - 100 100 4 1 - 51 1 -/1 - - - - 13 10/10/0/0 -/- - 100 100 5 0 - 45 1 -/- - - - - 15 0/0/0/0 -/- - 85 100 6 0 - 21 1 -/- 1 - - - 19 85 100‡ 7 1 + 61 1 -/2 - - - - 12 0/0/0/0 -/- - 100 100 8 0 + 45 1 -/1 - - - - 13 0/20/0/0 -/- C 100 85 9 0 + 26 1 -/- 1 - - - 18 0/15/0/ -/- - - 100 10 0 - 56 1 -/1 - - - - 15 0/0/0/0 -/2 - 65 95 11 1 - 55 1 -/1 2 - - - 12 0/0/0/0 -/- - 100 100 12 0 + 42 1 -/- - - - - 14 0/0/0/0 -/- C,W 85 85 13 0 + 52 1 -/1 2 - - - 13 10/0/0/ -/- - 85 100 14 1 + 29 1 -/1 1 - - - 13 0/0/0/0 -/- S 100 100 15# 0 + 44 1 -/- - - - - 13 15/5/0/10 -/- C 95 100 16 1 + 20 1 -/- 1 - - - 12 0/0/0/10 -/- - 100 100 17 1 - 60 1 -/- - - - - 13 0/0/0/0 -/- - 100 100 18 0 - 48 2 -/- - - - - 12 0/15/0/0 -/- - 100 100 19 1 + 35 2 -/2 2 - - L 13 5/0/0/0 -/- L 85 85 20 0 - 45 2 -/2 - - - - 12 10/40/0/0 -/- C 85 85 21 0 + 53 2 -/- 2 - - - 13 0/10/0/0 -/- - 100 100 22 1 + 53 2 -/- 2 - - - 12 0/0/0/0 -/- - 100 100 23 0 + 75 2 -/2 3 - - - 12 0/20/0/0 -/- - 100 100 24 1 - 37 2 -/0 - - - - 19 10/5/0/0 -/- - 85 100 25 1 + 22 2 -/0 - - - - 12 0/0/0/0 -/- - 100 100 26 0 - 60 2 -/0 - - - - 12 0/0/0/0 -/- C 100 100 27 0 - 61 2 -/1 1 - - - 13 5/10/0/0 -/- - 100 100 28# 0 - 44 2 -/2 - - - L 13 15/5/0/10 -/- C 95 100 29 0 - 25 2 -/1 - - - - 12 10/10/0/0 -/- C 65 85 30 0 + 36 2 -/- - - - - 13 0/0/0/0 -/- - 100 100 31 0 - 38 2 -/- - - - - 13 5/0/0/0 -/- C 100 100 32 0 - 69 2 -/0 - - - - 16 0/10/0/0 -/- C 100 100 33* 1 + 28 2 -/- - - - - 14 5/0/0/0 -/- - 100 100 34 1 + 59 2 -/1 - - - - 13 0/10/5/0 -/- - 85 100 35 1 + 54 2 -/2 1 - - - 12 5/30/0/0 -/- C 85 100 36 0 - 34 2 -/- - - - - 13 0/0/0/0 -/- - 65 100 37 0 + 53 3 -/3 - - - - 15 0/15/0/10 -/- C 100 100 Clinical relevance of MRI fi ndings 75

38 0 + 68 3 2/2 - - 1 - 13 95 100‡ 39 1 + 45 3 -/1 1 - - M 13 15/10/0/0 2/- C,W 80 80 40 0 + 51 3 -/1 - - 1 - 12 0/5/0/0 2/- C 100 95 41 0 - 64 3 x/x - 1 - M 12 10/10/0/10 -/- - 85 100 42 0 - 52 3 -/2 3 - - - 12 25/10/0/0 -/- - 95 100 Table III: Pati ents characteristi cs, MRI fi ndings and clinical results aft er the mean follow-up of 13.3 months, summarised per pati ent. Legends to table 3: A = Number of subject B = Sex: 0 = female, 1 = male C = Dominant side D = Age (years) E = Mason-Hotchkiss type F = MCL/LCL lesion: 0 = contusion, 1 = parti al, 2 = complete, 3 = avulsion fracture G = Capitellum: 1 = bone oedema, 2 = chondral damage, 3 = fracture H = Coronoid fracture: 1 = type I, 2 = type II and 3 = type III I = Dislocati on of the elbow joint J = Other: M = Movement artefacts, L = loose body K= Follow-up period in months L = Flexion/extension/pronati on/supinati on defi cit M = Grade of instability: MCL/LCL N = Complaints: E = elbow pain, C = Crepitus, L = Locking, W= Wrist pain, S = Snapping O = MEPS aft er 3.5 months P = MEPS aft er 13.3 months, ‡ = MEPS obtained by phone 6 x = No reliable observati on because of movement artefact. * and # = bilateral fracture of the radial head in two pati ents.

RESuLTS

MRI scanning results With MRI, 2 elbows with a presumed Mason type II fracture, were reclassifi ed as a Mason type I fracture. In 32 of the 42 elbows (76%), 45 concomitant injuries were diagnosed with MRI, and 12 pati ents with a type I fracture, 14 with a type II fracture and 6 with a type III fracture appeared to have associated injuries. LCL injuries were diagnosed in 25 pati ents. Injury to the LCL occurred in 47% of the Mason type I fractures compared with 63% and 83% in type II and III fractures; however, this increase in incidence was not stati sti cally signifi cant (p=0.10) A complete MCL rupture was seen in 1 pati ent, capitellar injuries occurred in 16, osteochondral loose bodies were found in 2, and a Regan and Morrey type I coronoid fracture was seen in 1. Results are summarized in table II. MRI fi ndings per pati ent are presented in table III.

Clinical fi ndings At the follow-up period of 13.3 months, a fl exion defi cit occurred in 19 of 42 elbows(45%) and was a mean of 3.9° (range: 0-25). An extension defi cit occurred in 15 elbows (43%) and was a mean of 6.4° (range: 0-40). Seven (16%) elbows had supinati on defi cit and the 76 Chapter 6

Type of associated symptoms Number of patients Grade 3.5 months 13.3 months LCL instability I 4 - II - 1 II - - MCL instability I 1 - II 2 2 III - - Crepitus 11 13 Locking 0 1 Wrist pain 6 2 Table IV: Clinical findings of the patients after 3.5 and 13.3 months.

mean supination deficit was 1.3° (range: 0-10). Pronation was equal to the unaffected side in all patients. A non-painful crepitus was present in 13 patients, of which 1 patient had chondral damage of the capitellum with MRI. One of the 2 patients with a loose body on MRI had an infrequent non-painful elbow locking. One other patient experienced non-painful elbow snapping. These symptoms were mild and neither patient needed surgery. Two patients presented with a pain at the wrist, but further evaluation by an upper extremity specialist did not reveal any signs of longitudinal instability. One patient with a type I fracture oc- casionally used analgesics for elbow pain. All patients resumed their original professions except 1 patient who had a type I fracture without associated injuries. The mean MEPS was 92.8 (range: 65-100) after 3.5 months and 97.5 (range: 80-100) after 13.3 months: 6 elbows scored a good result after 13.3 months, and 36 scored an excellent result. There was no statistically significant difference in MEPS between patients with and without associated injuries (p = 0.8). At 3.5 months, a grade I varus laxity was present in 4 elbows (2 Mason type I and 2 Mason type II fractures), which were asymptomatic and stable at the evaluation after 13.3. months. In 2 of these patients an LCL injury was diagnosed with MRI. A grade II varus laxity was diagnosed in 1 elbow with a Mason type I fracture at 13.3 months. This patient had no laxity at 3.5 months and had a partial LCL lesion with MRI, but did not experience pain or instability complaints of the injured elbow at follow-up. The MRI-documented LCL lesion of the patient with type III fracture who underwent surgical treatment was confirmed and reconstructed during surgery. A grade I valgus laxity was diagnosed in 1 elbow with a Mason type II fracture and a grade II valgus laxity in 2 elbows with a Mason type III fracture at the follow-up of 3.5 months. At 13.3 months 2 patients Mason type III fracture had a grade II valgus laxity, of which one was symptomatic with heavy lifting. This patient did not have surgical MCL reconstruction as the complaints were only incidental. The other patient had no objective Clinical relevance of MRI fi ndings 77 laxity at 3.5 months of follow-up. In these 2 pati ents the MCL was diagnosed as intact with MRI. The pati ent with the complete MCL rupture on MRI completed a telephone interview aft er 13 months. Stability could not be objecti vely tested, but the pati ent did not experience subjecti ve elbow instability. Clinical results are summarized in table IV and clinical results per pati ents are presented in table III. Medical records were reviewed of the 4 pati ents lost to follow-up, all with Mason type II fractures: one pati ent did not appear on the out-pati ent clinic aft er the primary visit to the ED, another pati ent was seen on the out-pati ent clinic 10 days aft er trauma and acti ve mobilisati on was advised. The third pati ent had an extension defi cit of 10° with normal pro- and supinati on 3 weeks aft er trauma. The fourth pati ent had an extension defi cit of 25° at 4 months aft er trauma and was advised physiotherapy en re-evaluati on if no functi onal improvement was achieved. This pati ent did not return for re-evaluati on. Stability was not tested in all these pati ents.

DISCuSSIOn

This study shows that concomitant injuries of the elbow with a radial head fracture are common, but not always symptomati c. MRI led to the diagnosis of associated injuries in 6 32 of 42. Only 2 of 45 (4.4%) MRI fi ndings were symptomati c at a mean follow-up of 13.3 months. MRI was used to diagnose 22 parti al or complete ruptures of one of the collateral ligaments of the elbow. Aft er 13.3 months follow-up, laxity of the elbow was seen in only 1 of these cases. This pati ent did not report subjecti ve elbow instability; however, this was a low-demand sedentary pati ent. In the pati ents with ligamentous injury without elbow laxity, suffi cient clinical elbow stability may be provided by the remaining part of the injured ligament, the intact osseous constraint, and the secondary stabilizers, as the common extensor tendon and the common fl exor-pronator tendon.13 Another explanati on may be the potenti al self-healing power of the collateral ligaments, as has been described for the ankle and knee14, 15, or that a pseudo-instability existed as result of an insuffi cient radial head. A fourth explanati on is that the specifi city and sensiti vity of the MR images could be low, as in this populati on 2 elbows had MCL laxity at 13.3 months follow-up, without a lesion with MRI. MRI has a reported sensiti vity of 57-100% and a specifi city of 100% in complete MCL rupture.16, 17 MRI has a sensiti vity of only 57% and a specifi city of 100% in detecti ng parti al ruptures of the MCL.17 Pott er et al. have shown that MRI is highly sensiti ve and specifi c for LCL pathology in pati ents with posterolateral instability.18 MRI-arthrography (MRA) improves the sensiti vity and specifi city of parti al ligament rupture and MRA is preferred for diagnosis of loose bodies.19, 20 If joint eff usion is present, as is the case in our pati ents who were scanned in the acute phase aft er radial head fracture, MRI without contrast is preferred.21 We did 78 Chapter 6

not investigate inter- and intra-observer reliability, as Itamura et al. found a coefficient variation less than 5% for intra-observer reliability and the F-test between two observers was not statistically significant for each MRI set.4 Several studies in the past 10 years have shown a high incidence of associated injuries with radial head fractures. MRI has found associated injuries ranging from ligamentous injuries to capitellar bone bruise are found in 76 to 96% of the patients with a radial head fracture.4, 10 In a retrospective study of 333 patients with a radial head fracture by van Riet et al., clinically relevant associated injuries of the ipsilateral upper extremity were diagnosed in 39%.5 The Mayo classification of radial head fractures was based on this study, and accounts for these clinically relevant injuries, by addition of a suffix to the original Mason classification.22 It was not used in the current study, as all associated injuries were detected by MRI and it was our goal to examine the clinical relevance of these lesions. Our study is the first study that attempts to correlate the results of MRI in patients with a radial head fracture with clinical findings. It also provides a possible explanation of the difference between the high incidence of concomitant injuries found with MRI4, 10 and the lower incidence of clinically relevant associated injuries on physical examination found by van Riet et al.5 Hausmann et al.23 found partial ruptures of the interosseous membrane using MRI of the forearm in 9 of 14 patients with a Mason type I radial head fracture, of whom 7 were symptomatic. This suggests that lesions of the interosseous membrane is more frequent than expected. In this study 2 of 42 elbows had wrist pain after 13.3 months of follow-up, although no signs of an ALRUD were found. The study by Hausmann could explain the wrist pain of the patients in our study, although we did not visualize the interossous membrane. The incidence of LCL injuries noted by MRI suggests a trend of increasing injury in radial head fractures of increased severity (Mason type II and III), but due to small patients numbers, this increase is not statistically significant. However, van Riet et al.5 already showed a significant increased likelihood of associated injuries as the radial head fracture severity increases. Johansson found ligament or capsular disruption by arthrography in 4% of type I, 21% of type II and 85% of type III fractures.24 An important limitation of this study is that 10 cases underwent surgery without having a MRI, as the MRI would adversely delay their treatment. The incidence of associated injuries in these patients can be expected to be higher owing to the type of their lesions.5 This deficiency has the potential to skew results, because these excluded patients also had radial head fractures with concomitant elbow dislocation or ulnar fracture. In these severe injuries, one might suspect a higher incidence of associated pathology and that such pathology might be clinically more relevant. Diagnosis and understanding of the concomitant injuries in these patients is of great importance for an adequate treatment.2, 25 A pre-operative MRI might help with pre-operative planning and could be of benefit for this group. However, assessment during surgery is a good alternative, for example, stability Clinical relevance of MRI fi ndings 79 testi ng under fl uoroscopy, and evaluati on of the carti lage of the capitellum during ORIF of the radial head. Mason type I and (borderline) type II radial head fractures were mostly included in this study. Most pati ents with these fracture types usually do well with conservati ve treatment, as was noted in this study. The MRI fi ndings in these pati ents did not nor would have infl uenced treatment. Four pati ents, all with a Mason type II fracture, were lost to follow-up. This is a considerable number and may have infl uenced the results of this study; however, a review these pati ents’ medical records indicated that good functi onal results are likely. An advantage of this study is the relati ve large number of pati ents compared with other clinical studies of radial head fractures. However, the populati on in this study is too diverse and too small to draw fi rm conclusions on the clinical relevance of associated injuries in subgroups. Follow-up was relati vely too short to assess the precise clinical consequences of the osteochondral lesions, as these pati ents might be more prone to develop osteoarthriti s in later life compared to those without osteochondral lesions.

COnCLuSIOnS

A high number of associated injuries is detected in pati ents with radial head fractures. 6 Associated injuries were diagnosed with MRI in 32 of 42 elbow with a Mason type I to III radial head fracture. However, the vast majority of these fi ndings were not were symptomati c aft er 13.3 months of follow-up.

ACKnOwLEDGEMEnTS

The authors would like to thank I.N. Sierevelt, MSc, Department of Orthopaedic Surgery, Academic Medical Center, Amsterdam, the Netherlands, for her help with the stati sti cal analysis of the collected data and H.A.J. Dijkstra, MD, Department of Radiology, Amphia Hospital, Breda, the Netherlands, for his contributi on to the interpretati on of the MRI images. 80 Chapter 6

REFEREnCE LIST

(1) Herbertsson P, Josefsson PO, Hasserius R, Karlsson C, Besjakov J, Karlsson MK. Displaced Mason type I fractures of the radial head and neck in adults: a fifteen- to thirty-three-year follow-up study. J Shoulder Elbow Surg 2005 Jan; 14(1): 73-7. (2) van Riet RP, van Glabbeek F, Morrey BF. Radial Head Fracture: General Considerations, Conservative Treatment and Open Reduction and Internal Fixation. In: Morrey B, Sanchez-Sotelo J, editors. The Elbow and its Disorders. 4 ed. Philadelphia: Saunders; 2009. p. 359-81. (3) Hotchkiss RN. Displaced fractures of the radial head: internal fixation or excision? J Am Acad orthop Surg 1997; 5: 1-10. (4) Itamura J, Roidis N, Mirzayan R, Vaishnav S, Learch T, Shean C. Radial head fractures: MRI evaluation of associated injuries. J Shoulder Elbow Surg 2005 Jul; 14(4): 421-4. (5) van Riet RP, Morrey BF, O’Driscoll SW, van Glabbeek F. Associated injuries complicating radial head fractures: a demographic study. Clin Orthop Relat Res 2005; 441: 351-5. (6) Kaas L, van Riet RP, Vroemen J, Eygendaal D. The epidemiology of radial head fractures. J Shoulder Elbow Surg 2010 Jun 1; 19(4): 520-3. (7) Davidson PA, Moseley JB, Jr., Tullos HS. Radial head fracture. A potentially complex injury. Clin Orthop Relat Res 1993 Dec; (297): 224-30. (8) Steinmann SP. Coronoid process fracture. J Am Acad Orthop Surg 2008 Sep; 16(9): 519-29. (9) Nalbantoglu U, Gereli A, Kocaoglu B, Aktas S, Turkmen M. Capitellar cartilage injuries concomitant with radial head fractures. J Hand Surg (Am) 2009; 33(9): 1602-7. (10) Kaas L, Turkenburg JL, van Riet RP, Vroemen J, Eygendaal D. Magnetic resonance imaging findings in 46 elbows with a radial head fracture. Acta Orthopaedica 2010; 81(3): 373-6. (11) Morrey BF, An KN, Chao E. Functional evaluation of the elbow. In: Morrey.BF., editor. The elbow and its disorders. 2 ed. Philadephia: Saunders; 1993. p. 86-97. (12) Regan W, Morrey BF. Fractures of the coronoid process of the ulna. J Bone Joint Surg 1989; 71A: 1348-54. (13) O’Driscoll SW, Jupiter JB, King GJ, Hotchkiss RN, Morrey BF. The unstable elbow. Instr Course Lect 2001; 50: 89-102. (14) Woo SL, Chan SS, Yamaji T. Biomechanics of knee ligament healing, repair and reconstruction. J Biomech 1997 May; 30(5): 431-9. (15) Safran MR, Benedetti RS, Bartolozzi AR, III, Mandelbaum BR. Lateral ankle sprains: a comprehensive review: part 1: etiology, pathoanatomy, histopathogenesis, and diagnosis. Med Sci Sports Exerc 1999 Jul; 31(7 Suppl): S429-S437. (16) Sonin AH, Fitzgerald SW. MR imaging of sports injuries in the adult elbow: a tailored approach. AJR Am J Roentgenol 1996 Aug; 167(2): 325-31. (17) Timmerman LA, Schwartz ML, Andrews JR. Preoperative evaluation of the ulnar collateral ligament by magnetic resonance imaging and computed tomography arthrography. Evaluation in 25 baseball players with surgical confirmation. Am J Sports Med 1994 Jan; 22(1): 26-31. (18) Potter HG, Weiland AJ, Schatz JA, Paletta GA, Hotchkiss RN. Posterolateral rotatory instability of the elbow: usefulness of MR imaging in diagnosis. Radiology 1997 Jul; 204(1): 185-9. (19) Schwartz ML, al-Zahrani S, Morwessel RM, Andrews JR. Ulnar collateral ligament injury in the throwing athlete: evaluation with saline-enhanced MR arthrography. Radiology 1995 Oct; 197(1): 297-9. (20) Brunton LM, Anderson MW, Pannunzio ME, Khanna AJ, Chhabra AB. Magnetic resonance imaging of the elbow: update on current techniques and indications. J Hand Surg Am 2006 Jul; 31(6): 1001-11. Clinical relevance of MRI fi ndings 81

(21) Shahabpour M, Kichouh M, Laridon E, Gielen JL, De Mey J. The eff ecti veness of diagnosti c imaging methods for the assessment of soft ti ssue and arti cular disorders of the shoulder and elbow. Eur J Radiol 2008 Feb;65(2): 194-200. (22) van Riet RP, Morrey BF. Documentati on of associated injuries occurring with radial head fracture. Clin Orthop Relat Res 2008 Jan;466(1): 130-4. (23) Hausmann JT, Vekszler G, Breitenseher M, Braunsteiner T, Vecsei V, Gabler C. Mason type-I radial head fractures and interosseous membrane lesions--a prospecti ve study. J Trauma 2009 Feb; 66(2): 457-61. (24) Johansson O. Capsular and ligament injuries of the elbow joint. A clinical and arthrographic study. Acta Chir Scand Suppl 1962;Suppl 287:1-159. (25) O’Driscoll SW, Jupiter JB, Cohen MS, Ring D, McKee MD. Diffi cult elbow fractures: pearls and pitf alls. Instr Course Lect 2003;52: 113-34. (26) Akesson T, Herbertsson P, Josefsson PO, Hasserius R, Besjakov J, Karlsson MK. Primary nonoperati ve treatment of moderately displaced two-part fractures of the radial head. J Bone Joint Surg Am 2006 Sep;88(9): 1909-14.

Chapter 7 Ulnar collateral ligament injury

Denise Eygendaal, Laurens Kaas

Evidence Based Orthopedics, 1st edition. M. Bhandari (ed.) Wiley-Blackwell, Oxford; 2012: Page 781-786. 84 Chapter 7

CASE SCEnARIO

A 23 year old professional athlete (baseball pitcher) has been complaining about his right elbow for 6 months. The pain is medial sided and the onset of the symptoms was gradual. A wrong pitch 5 months ago has severely increased the pain, resulting in an inability to pitch. At physical examination there is a slight extension deficit of 10°, a positive moving valgus test and a positive milking test.1 This test can identify partial tears of the ulnar collateral ligament (UCL) by extending the elbow from the fully flexed position, while the examiner exerts a valgus moment by grasping the thumb and resisting extension. The patient has no neurovascular symptoms.

RELEVAnT AnATOMy

Stability of the elbow is attained by dynamic and static constraints. Static or passive constraints are provided by both the bones and the soft tissues of the elbow. The role of the muscles as dynamic constraints is becoming increasingly clear and is probably larger than previously postulated. The relative role of the osseous and soft tissue restraints are shown in table I. The ulnar collateral ligament consists of an anterior and a posterior bundle, and a transverse ligament (also known as the Cooper ligament). The anterior and posterior bundles originate from a broad anteroinferior surface of the medial humeral epicondyle. The anterior bundle inserts the base of the coronoid process of the ulna and the posterior bundle inserts the medial part of the semilunar notch of the ulna. The mean length of the anterior UCL is 27.1 mm and that of posterior UCL 24.2 mm, the mean widths are about 4.7 mm and 5.3 mm respectively. The function of these ligaments is to restrain valgus stress, during extension (anterior bundle) and during flexion (posterior bundle). Studies reveal that the anterior medial collateral ligament can be subdivided into three regions or bands according to their function (see figure 1).2-4

IMPORTAnCE OF THE PRObLEM

Injury to the UCL was first recognized in 1946 in javelin throwers.5 The injury has since become well recognized in baseball pitchers and other overhead throwing athletes. However,

Extended 90° elbow flexion MCL 31 54 Soft tissue, capsule 38 10 Osseous articulation 31 33 Table 1: Relative contribution to valgus stress resistance (%).37 UCL instability of the elbow 85

Figure 1. The UCL complex consists of an anterior (1) and a posterior(2) bundle, and a transverse ligament.3 (reproduced with permission) exact numbers or incidence of this injury in athletes or in the general populati on are not known. The three most common causes of UCL injury are elbow dislocati on, chronic at- tenuati on in athletes or acute valgus injury. The elbow joint is the second most commonly 7 dislocated major joint aft er the shoulder. In children it is the most commonly dislocated joint.6 The incidence of this dislocati on is esti mated to be 6/100,000 in the general populati on, usually in the posterior or posterolateral directi on.7 Josefsson8 showed that elbow dislocati on induced injury in the lateral as well as the medial ligamentous structures, whereas O’Driscoll9 demonstrated that the joint could be dislocated experimentally with preservati on of the medial ligaments. During dislocati on ligamentous injury occurs in a lateral to medial circle. In stage 1, the radial collateral ligament is disrupted; in stage 2, the other lateral ligamentous structures as well as the anterior and posterior capsule are disrupted. In stage 3, disrupti on of the UCL can be parti al with disrupti on of the posterior bundle only (3A) or complete (3B).9 The UCL can therefore be disrupted aft er dislocati on of the elbow joint. Persistent valgus instability aft er conservati ve treatment of elbow dislocati on has been described in up to 50%. It is related to degenerati ve changes of the elbow joint aft er an average follow-up of 9 years.10 86 Chapter 7

TOP 5 QuESTIOnS

Diagnosis 1. Is UCL insufficiency a frequently encountered problem in general orthopedic practice? 2. As the clinical instability of the elbow is underestimated in most cases, what is de ‘gold standard’ for the evaluation of the UCL?

Treatment 3. Should (professional) athletes with an acute injury of the UCL always be treated surgically? 4. What are the surgical treatment options?

Prognosis 5. Does surgical reconstruction of the UCL prevent accelerated degeneration of the elbow joint?

QuESTIOn 1: IS uCL InSuFFICIEnCy A FREQuEnTLy EnCOunTERED PRObLEM In GEnERAL ORTHOPEDIC PRACTICE?

Case clarification The patient was treated in an upper limb unit specializing in sports medicine. In a general orthopedic practice with a small number of sports-related injuries or post-traumatic de- formities of the elbow, the incidence is low. In those situations the ‘doctor’s delay’ due to unfamiliarity with UCL injury can be an issue.

Finding the evidence - Cochrane Database: No reviews available. - PubMed: No reports on incidence of UCL injury of the elbow in the general population or in throwing athletes.

Findings There are no scientific reports on the incidence of UCL injury in throwing athletes or the general population. One study found an incidence of UCL lesions in 33% of 490 baseball players who underwent rehabilitation for any kind of injury of the upper extremity.11 As previously mentioned, persistent valgus instability after conservatively treated elbow dislocations has been described in up to 50% of the cases.10 In up to 54% of the patients with a radial head fracture a UCL lesion is diagnosed with MRI, although the incidence of clinical relevant UCL injuries is much lower (1-8%).12-15 Orthopedic surgeons should think UCL instability of the elbow 87 of UCL insuffi ciency in pati ents with medial sided elbow pain especially in athletes and in pati ents with postt raumati c conditi ons of the elbow as a posterolateral dislocati on.

Recommendati ons - UCL insuffi ciency of the elbow has been mainly reported in athletes and in pati ents with post-traumati c conditi ons of the elbow as a postero-lateral dislocati on, although the incidence in the general (or athlete) populati on is unknown. [Overall quality very low]

QuESTIOn 2: AS THE CLInICAL InSTAbILITy OF THE ELbOw IS unDERESTIMATED In MOST CASES, wHAT IS DE ‘GOLD STAnDARD’ FOR THE EVALuATIOn OF THE uCL?

Case clarifi cati on In the case described above, the history was very suggesti ve for UCL injury. Apparently this athlete had ruptured the UCL 5 months ago, but this injury had subsided; aft er a new event, the ‘chronic rupture’ of UCL became symptomati c again. Physical examinati on revealed a positi ve milking maneuver; the MRI with arthrogram (MRA) revealed a detachment of the UCL on the humeral side.

Current opinion Anteropostererior, lateral and axillary views of the elbow are assessed for degenerati ve 7 changes, such as joint space narrowing, ossifi cati on of the UCL and loose bodies. A small bony avulsion fragment might be identi fi ed when a UCL bony avulsion exists.

Finding the evidence - Cochrane Database: No reviews available - PubMed: 7 reports on MRA in UCL pathology. 2 reports on CTA in UCL pathology.

Quality of the evidence - Level IV: 6 case series. - Level V: 2 expert opinion.

Findings Dynamic radiographs under valgus load have been described in the past as a useful diagnosti c tool; however mild valgus laxity has been observed in uninjured overhead athletes and dynamic radiographs in symptomati c elbows seems to be inconsistent.16, 17 Another imaging modality is CT with arthrogram (CTA), with a sensiti vity of 86% and a specifi city of 91%.18 However, the preferred imaging technique for UCL injuries of the elbow is MRA. 88 Chapter 7

MRI is capable of identifying full thickness tears, MRA improves the diagnosis of partial tears. 17, 19-22 Another advantage of MRI/MRA is the ability to identify associated pathology, such as medial epicondylitis and chondral lesions. Sensitivity of MRA is reported to be up to 97% in detecting UCL injury, including partial undersurface UCL tears, with a specificity of up to 100%.18, 23, 24 No comparative studies between CTA and MRA are currentlu available.

Recommendations - MRA is the preferred imaging technique for detection of UCL injuries of the elbow. [Overall quality very low]

QuESTIOn 3: SHOuLD (PROFESSIOnAL) ATHLETES wITH An ACuTE InjuRy OF THE uCL ALwAyS bE TREATED SuRGICALLy?

Case clarification Treatment of UCL of the elbow injuries is based on the patients athletic demands and the degree of UCL injury. Initial conservative treatment consists of rest, anti-inflammatory measures and physical therapy.

Finding the evidence - Cochrane Database: No reviews on conservative treatment of UCL available - PubMed: 1 report on conservative treatment of UCL injury of the elbow

Quality of the evidence - Level IV: 1 case series.

Findings Rettig et al. 25 was the first to report on the results of conservative treatment in throwing athletes. Phase I of the conservative treatment consisted of rest and modalities to treat symptoms for 2 to 3 months. If pain free, the athlete began with phase II which consisted of muscle strengthening and throwing. Thirteen of 31 athletes (42%) returned to same level of play, with an average return of 24 weeks after injury after conservative - treat ment. This rehabilitation period is shorter compared to the rehabilitation period after UCL reconstruction. No history or physical examination features are predictive for athletes who will respond to no non-operative treatment. UCL instability of the elbow 89

Recommendati ons - reatment of UCL of the elbow injuries is based on the pati ents athleti c demands and the degree of UCL injury. [Overall quality very low]

QuESTIOn 4: wHAT ARE THE SuRGICAL TREATMEnT OPTIOnS?

Current opinion Persistent symptomati c UCL instability aft er initi al conservati ve treatment is an indicati on for reconstructi on.

Finding the evidence - Cochrane Database: 0 reviews available on results of UCL reconstructi on. - PubMed: 17 reports available on results of UCL reconstructi on.

Quality of the evidence - Level I: 2 systemati c reviews. - Level IV: 14 case series. - Level V: 1 expert opinion.

Findings The fi rst successful UCL reconstructi on was performed in 1974 by Dr. Frank Jobe and 7 colleagues. They published their initi al results in throwing athletes in 1986, using the palmaris longus tendon as an autograft , with detachment of the fl exor-pronator muscu- lature, submuscular transpositi on of the ulnar nerve and a fi gure-of-eight graft fi xati on technique. In this fi xati on technique the autograft is placed through two drill holesin the ulna and three in the medial epicondyle in a fi gure-of-eight fashion, going through the posterior humeral cortex and suturing the graft to itself.26 Several modifi cati ons of this original technique have been introduced over the past 35 years. Muscle splitti ng instead of detachment and abandoning the obligatory ulnar nerve transpositi on, improved clinical results and decreased the complicati on rate.27, 28 The introducti on of the docking technique by Rohrbough et al.29 allows easier graft passing, tensioning and fi xati on. It uses the same ulnar tunnels as in the Jobe technique, but the humeral tunnels are created with one single inferior tunnel, with two small superior and one anterior exit tunnels. The graft is positi oned in the inferior tunnel, and tensioned with sutures that exit the superior tunnels. The graft is fi xated by tying the sutures over a bony bridge. Another graft fi xati on technique is interference screw fi xati on, where one or both graft endings are fi xed with a bioabsorbable interference screw.23, 30 Diff erent autograft s have been described: the palmaris longus tendon, plantaris tendon, hamstrings tendon, tendon 90 Chapter 7

allografts or triceps tendon can be used.27, 30 Ulnar decompression or transposition can be indicated in patients with symptoms of ulnar nerve irritation, which is present in over 40% of the patients with UCL insufficiency.16 Additional diagnostic arthroscopy can be performed if intra-articular pathology is suspected.23, 29 After surgery a long arm cast is applied for 1-2 weeks to allow wound healing. Some authors use an additional hinged brace during mobilization for 2-6 weeks. Strengthening exercises (with or without brace) are initiated after 4-6 weeks. Throwing is usually allowed after 2-5 months. Return to competition- var ies between ‘when ready’ to 12 months after surgery.23, 31-35 The original report on UCL reconstruction by Jobe et al. reported excellent results in 63%.26 With the improvement of the surgical technique, success rates increased: 74-95% of all athletes returned to their previous level of injury or higher.16, 34, 36 Previous surgery for UCL insufficiency is associated with poorer results.16, 17 The most frequent reported complication is a transient ulnar neuropathy, which occurs in 1-21% of the patients, with a mean of 6%. About 1% of the patients experience graft site complications.27 In this case UCL reconstruction is advised, if conservative treatment under supervision of a specialized physiotherapist for 3 months, is not successful.

Recommendations - Symptomatic UCL insufficiency is indication for reconstruction. Reconstruction ofa non-symptomatic UCL injury is not indicated. [Overall quality very low] - The preferred surgical techniques are the docking technique or interference screw fixation. [Overall quality very low] - Injury to the UCL of the elbow was once a career-ending-injury in overhead athletes, UCL reconstruction have made return to previous of higher level of athlete participa- tion in sports likely to occur. [Overall quality very low]

QuESTIOn 5: DOES SuRGICAL RECOnSTRuCTIOn OF THE uCL PREVEnT ACCELERATED DEGEnERATIOn OF THE ELbOw jOInT?

Current opinion Persistent valgus instability can be related to accelerated degeneration of the elbow joint. The question whether surgical reconstruction of the UCL can prevent accelerated degeneration of the elbow has not been answered yet.

Finding the evidence - Cochrane Database: No reviews available on prevention of degeneration with UCL reconstruction. - PubMed: No reports available on prevention of degeneration with UCL reconstruction. UCL instability of the elbow 91

Findings Symptomati c UCL insuffi ciency is indicati on for reconstructi on; a reconstructi on of UCL to prevent further damage to the joint in the future is not indicated. Reconstructi on of a non-symptomati c UCL injury is not indicated.10

Recommendati ons - A reconstructi on of the UCL to prevent further damage to the joint in the future is not indicated. [Overall quality very low]

SuMMARy OF RECOMMEnDATIOnS

- UCL insuffi ciency of the elbow has been mainly reported in athlete’s and in pati ents with postt raumati c conditi ons of the elbow as a postero-lateral dislocati on, although the incidence in the general (or athlete) populati on is unknown. - The preferred imaging technique for detecti on of UCL injuries of the elbow is MRI with arthrography. - Treatment of UCL of the elbow injuries is based on the pati ents athleti c demands and the degree of UCL injury. - Symptomati c UCL insuffi ciency is indicati on for reconstructi on. Reconstructi onofa non-symptomati c UCL injury is not indicated. - The preferred surgical techniques are the docking technique or interference screw 7 fi xati on. - Injury to the UCL of the elbow was once a career-ending-injury in overhead athletes, UCL reconstructi on have made return to previous of higher level of athlete parti cipa- ti on in sports likely to occur. - A reconstructi on of the UCL to prevent further damage to the joint in the future is not indicated.

COnCLuSIOnS

Research on diagnosis and treatment of UCL injury should conti nue to fi nd higher levels of evidence. Prospecti ve studies to determine preferable diagnosti c technique, best graft fi xati on techniques and long term results of conservati ve and surgical treatment are in demand. 92 Chapter 7

REFEREnCE LIST

(1) Veltri DM, O’Brien SJ, Field LD, Altchek DW, Warren RF. The milking maneuvre. In: 10th Open Meet- ing of the American Shoulder and Elbow Surgeons, New Orleans, 1994. (2) Callaway GH, Field LD, Deng XH, Torzilli PA, O’Brien SJ, Altchek DW, et al. Biomechanical evaluation of the medial collateral ligament of the elbow. J Bone Joint Surg Am 1997 Aug; 79(8): 1223-31. (3) Regan WD, Korinek SL, Morrey BF, An KN. Biomechanical study of ligaments around the elbow joint. Clin Orthop Relat Res 1991 Oct; (271): 170-9. (4) Eygendaal D, Olsen BS, Jensen SL, Seki A, Sojbjerg JO. Kinematics of partial and total ruptures of the medial collateral ligament of the elbow. J Shoulder Elbow Surg 1999 Nov; 8(6): 612-6. (5) Waris W. Elbow injuries in javelin throwers. Acta Chir Scand 1946; 93: 563-75. (6) Linscheid RL, Wheeler DK. Elbow dislocations. JAMA 1965 Dec 13; 194(11): 1171-6. (7) Josefsson PO, Nilsson BE. Incidence of elbow dislocation. Acta Orthop Scand 1986 Dec; 57(6): 537-8. (8) Josefsson PO, Johnell O, Wendeberg B. Ligamentous injuries in dislocations of the elbow joint. Clin Orthop Relat Res 1987 Aug; (221): 221-5. (9) O’Driscoll SW, Morrey BF, Korinek S, An KN. Elbow subluxation and dislocation. A spectrum of instability. Clin Orthop Relat Res 1992 Jul; (280): 186-97. (10) Eygendaal D, Verdegaal SH, Obermann WR, van Vugt AB, Poll RG, Rozing PM. Posterolateral dislocation of the elbow joint. Relationship to medial instability. J Bone Joint Surg Am 2000 Apr; 82(4): 555-60. (11) Han KJ, Kim YK, Lim SK, Park JY, Oh KS. The effect of physical characteristics and field position on the shoulder and elbow injuries of 490 baseball players: confirmation of diagnosis by magnetic resonance imaging. Clin J Sport Med 2009 Jul; 19(4): 271-6. (12) Itamura J, Roidis N, Mirzayan R, Vaishnav S, Learch T, Shean C. Radial head fractures: MRI evaluation of associated injuries. J Shoulder Elbow Surg 2005 Jul; 14(4): 421-4. (13) van Riet RP, Morrey BF, O’Driscoll SW, van Glabbeek F. Associated injuries complicating radial head fractures: a demographic study. Clin Orthop Relat Res 2005; 441: 351-5. (14) Kaas L, Turkenburg JL, van Riet RP, Vroemen J, Eygendaal D. Magnetic resonance imaging findings in 46 elbows with a radial head fracture. Acta Orthopaedica 2010; 81(3): 373-6. (15) Morrey BF. Current concepts in the treatment of fractures of the radial head, the olecranon, and the coronoid. Instr Course Lect 1995; 44: 175-85. (16) Conway JE, Jobe FW, Glousman RE, Pink M. Medial instability of the elbow in throwing athletes. Treatment by repair or reconstruction of the ulnar collateral ligament. J Bone Joint Surg Am 1992 Jan; 74(1): 67-83. (17) Thompson WH, Jobe FW, Yocum LA, Pink MM. Ulnar collateral ligament reconstruction in athletes: muscle-splitting approach without transposition of the ulnar nerve. J Shoulder Elbow Surg 2001 Mar; 10(2): 152-7. (18) Timmerman LA, Schwartz ML, Andrews JR. Preoperative evaluation of the ulnar collateral ligament by magnetic resonance imaging and computed tomography arthrography. Evaluation in 25 baseball players with surgical confirmation. Am J Sports Med 1994 Jan; 22(1): 26-31. (19) Cotten A, Jacobson J, Brossmann J, Pedowitz R, Haghighi P, Trudell D, et al. Collateral ligaments of the elbow: conventional MR imaging and MR arthrography with coronal oblique plane and elbow flexion. Radiology 1997 Sep; 204(3): 806-12. (20) Munshi M, Pretterklieber ML, Chung CB, Haghighi P, Cho JH, Trudell DJ, et al. Anterior bundle of ulnar collateral ligament: evaluation of anatomic relationships by using MR imaging, MR arthrography, and gross anatomic and histologic analysis. Radiology 2004 Jun; 231(3): 797-803. UCL instability of the elbow 93

(21) Kijowski R, Tuite M, Sanford M. Magneti c resonance imaging of the elbow. Part II: Abnormaliti es of the ligaments, tendons, and nerves. Skeletal Radiol 2005 Jan;34(1): 1-18. (22) Kaplan LJ, Pott er HG. MR imaging of ligament injuries to the elbow. Radiol Clin North Am 2006 Jul; 44(4):583-94, ix. (23) Azar FM, Andrews JR, Wilk KE, Groh D. Operati ve treatment of ulnar collateral ligament injuries of the elbow in athletes. Am J Sports Med 2000 Jan;28(1): 16-23. (24) Schwartz ML, al-Zahrani S, Morwessel RM, Andrews JR. Ulnar collateral ligament injury in the throwing athlete: evaluati on with saline-enhanced MR arthrography. Radiology 1995 Oct; 197(1): 297-9. (25) Retti g AC, Sherrill C, Snead DS, Mendler JC, Mieling P. Nonoperati ve treatment of ulnar collateral ligament injuries in throwing athletes. Am J Sports Med 2001 Jan;29(1): 15-7. (26) Jobe FW, Stark H, Lombardo SJ. Reconstructi on of the ulnar collateral ligament in athletes. J Bone Joint Surg Am 1986 Oct;68(8): 1158-63. (27) Vitale MA, Ahmad CS. The outcome of elbow ulnar collateral ligament reconstructi on in overhead athletes: a systemati c review. Am J Sports Med 2008 Jun; 36(6): 1193-205. (28) Purcell DB, Matava MJ, Wright RW. Ulnar collateral ligament reconstructi on: a systemati c review. Clin Orthop Relat Res 2007 Feb;455: 72-7. (29) Rohrbough JT, Altchek DW, Hyman J, Williams RJ, III, Bott s JD. Medial collateral ligament reconstructi on of the elbow using the docking technique. Am J Sports Med 2002 Jul; 30(4): 541-8. (30) Eygendaal D. Ligamentous reconstructi on around the elbow using triceps tendon. Acta Orthop Scand 2004 Oct;75(5): 516-23. (31) Palett a GA, Jr., Wright RW. The modifi ed docking procedure for elbow ulnar collateral ligament reconstructi on: 2-year follow-up in elite throwers. Am J Sports Med 2006 Oct; 34(10): 1594-8. (32) Koh JL, Schafer MF, Keuter G, Hsu JE. Ulnar collateral ligament reconstructi on in elite throwing athletes. Arthroscopy 2006 Nov;22(11): 1187-91. (33) Nissen CW. Eff ecti veness of interference screw fi xati on in ulnar collateral ligament reconstructi on. 7 Orthopedics 2008 Jul;31(7): 646. (34) Savoie FH, III, Trenhaile SW, Roberts J, Field LD, Ramsey JR. Primary repair of ulnar collateral ligament injuries of the elbow in young athletes: a case series of injuries to the proximal and distal ends of the ligament. Am J Sports Med 2008 Jun;36(6): 1066-72. (35) Bowers AL, Dines JS, Dines DM, Altchek DW. Elbow medial ulnar collateral ligament reconstructi on: clinical relevance and the docking technique. J Shoulder Elbow Surg 2010 Mar;19(2 Suppl):110-7. (36) Gibson BW, Webner D, Huff man GR, Sennett BJ. Ulnar collateral ligament reconstructi on in major league baseball pitchers. Am J Sports Med 2007 Apr;35(4): 575-81. (37) Morrey BF, An KN. Arti cular and ligamentous contributi ons to the stability of the elbow joint. Am J Sports Med 1983 Sep;11(5): 315-9.

Part IV Classification and treatment

Chapter 8 The Mason-Hotchkiss classification for radial head fractures: Intra- and inter-observer agreement

Laurens Kaas, Martijn A. van Hooft, Matthijs P. Somford, Leon H.G.J. Elmans, C. Niek van Dijk, Densie Eygendaal

Submitted 98 Chapter 8

AbSTRACT

Purpose: Only a few studies on inter- and intra-observer agreement of the Mason classification of radial head fractures or its modifications are available. None of these studies provide information on whether the clinicians experience view improves agreement. Methods: 46 radiographs of radial head fractures were classified according to the Mason- Hotchkiss classification by 4 observers with different levels of experience on 2 separate occasions. Results: The κ-value of intra-observer agreement was 0.72 and the inter-observer agreement ranged from 0.27 to 0.74. Surgeons scored an intra-observer agreement of 0.81, compared to a κ-value of 0.61 for residents. This difference was not statistically significant. The κ-value for intra-observer agreement for surgical or conservative treatment was 0.69, and inter-observer agreement ranged between 0.38 to 0.57. Conclusions: The inter-observer agreement was substantial and the intra-observer agreement ranged from fair to substantial. More clinical experience did not significantly improve agreement.Clini - cal relevance: Establishing the inter- and intra observer agreement of the Mason-Hotchkiss classification and the influence of clinical experience is of importance in decision making when treating patients with a radial head fracture. Study type: Diagnostic study. Level of evidence: Level III.

InTRODuCTIOn

The radiographic classification of radial head fractures by Mason in 1954 is widely used and has been adapted by several authors.1-4 Hotchkiss introduced a treatment-based modification, quantifying the amount of displacement and is frequently used in literature and as a guideline for decision making for treatment of radial head fractures in daily practice.5 (Table I) A fracture classification system should name and describe fracture according to their characteristics, providing a hierarchy of those characteristics. It should provide a guideline for a treatment or intervention and should predict a clinical outcome. Ideally, a classification should be valid, reliable and reproducible by observers with different levels of experience.6,7 Only a few studies are currently available on the inter- and intra-observer agreement of the Mason classification and its modifications.4,8-11 Only one study of the Mason-Hotchkiss classification is currently available.9 None of the studies on agreement of

Type Description I Undisplaced or minimally displaced (<2 mm) II Displaced fracture (>2 mm), amenable to internal fixation III Comminuted fracture, not amenable to internal fixation Table I: The Mason-Hotchkiss classification for radial head fractures.8 Intra- and interobserver reliability 99

Figure 1: Lateral radiograph of a Mason-Hotchkiss type II radial head fracture. the Mason classifi cati on and its modifi cati ons include an analysis of the impact of clinical experience on agreement. The main goal of this study was to determine whether radial head fractures could be classifi ed reliably with standard radiographs with Mason-Hotchkiss classifi cati on by diff erent observers with diff erent levels of experience and confi rm the results found by Sheps et al.9 The second purpose was to determine if diff erent observers 8 agree on treatment (conservati ve vs. surgery) of the radial head fracture as such, using the Mason-Hotchkiss classifi cati on as a guideline.

MATERIALS AnD METHODS

Anteroposterior and lateral elbow radiographs of 44 consecuti ve pati ents in a 5 month period, who presented at our emergency department with 46 intra-arti cular, radiographically visible radial head fractures at standard radiography, were included for this study. (Fig. 1) An additi onal RHC view of the elbow joint was made of 16 elbows. This RHC view was made to diagnose radiographic invisible radial head fractures on standard radiographs or on request of the treati ng physician and/or technician. Two elbows had associated osseous injuries (one coronoid fracture and one fracture of the lateral epicondyle) and 2 elbows presented with posterolateral dislocati on. The radiographs of the elbows were 100 Chapter 8

reviewed in an at random order by 4 independent observers with different levels of experience: 2 experienced orthopaedic surgeons (one upper extremity specialist and one traumatologist) and 2 residents in orthopaedic surgery with 3 and 4 years of clinical orthopaedic experience. All radiographs were viewed with IMPAX Web1000 software (Agfa HealthCare, Greenville, South Carolina). The radial head fractures were classified according to the Mason-Hotchkiss classification. (Table I) A written and illustrated description of this classification was provided to each observer. The radiographs were reviewed on two separate occasions in an at random order by the observers to determine the intra-observer agreement. Data collection and analysis was performed by an independent investigator. Institutional review board approval was not required for this study.

Statistical analysis Statistical analysis was performed with a Cohen’s weighted kappa12 with calculation of a standard error (SE) and a 95% confidence interval (CI) for the intra-observer agreement of the observations by the observers as one group, and the orthopaedic resident observers and orthopaedic surgeons as separate groups. Inter-observer agreement was calculated for each observer combination of the two separate observation moments. For statistical analysis between observers and observer-groups the Cohen’s weighted kappa12 was used and the SE and the 95% CI were calculated. As the Mason-Hotchkiss classification serves as a guideline for treatment, agreement was also measured for two types of treatment: non-operative and surgical treatment. For this purpose we combined the Mason type II and III fractures into one group. Inter- and intra observer agreement was calculated using the κ-statistic. Statistical significance was reached if there was no overlap between the 95% CI of 2 kappa-values. According to Landis and Koch,13 a κ-value of ≤ 0.20 represents slight agreement, 0.21 to 0.40 fair agreement, 0.41 to 0.60 moderate agreement, 0.61 to 0.80 substantial agreement and ≥ 0.81 high agreement. A κ-value of 0 represents no agreement and 1.0 represents perfect agreement. Statistical analysis was performed with SPSS 16.0 (SPSS, Chicago, Il) and Microsoft Excel 2007 (Microsoft Corporation, Redmond, WA) software.

RESuLTS

The mean period between the two viewing sessions was 5.8 weeks, with a range from 3 to 8 weeks. The intra-observer agreement of all observers was substantial: 0.72 (SE: 0.05). The intra-observer agreement of the surgeons was high: 0.81 (SE: 0.05) Residents scored substantial intra-observer agreement: 0.61 (SE: 0.08). The inter-observer agreement was moderate for both observer-groups: 0.44-0.45 for residents and 0.51-0.53 for surgeons. The agreement between surgeons and residents ranged from fair to moderate (0.27-0.60) Intra- and interobserver reliability 101

Type of Observers κ-value SE 95% CI agreement Intra-observer All 0.72 0.05 0.63-0.81 Surgeons 0.81 0.05 0.70-0.91 Residents 0.61 0.08 0.44-0.77 Inter-observer T1 Surgeons vs 0.28-0.60 - - residents Surgeons 0.51 0.11 0.29-0.73 Residents 0.44 0.11 0.23-0.66 Inter-observer T2 Surgeons vs 0.27-0.52 - - residents Surgeons 0.53 0.10 0.32-0.74 Residents 0.45 0.11 0.24-0.65 Table II: Intra- and inter-observer agreement of the Mason-Hotchkiss classifi cati on. T1 = fi rst observati on, T2 = second observati on, SE = Standard Error. CI = Confi dence Interval.

Type of Observers κ-value SE 95% CI agreement Intra-observer All 0.69 0.05 0.59-0.79 Surgeons 0.75 0.07 0.61-0.89 Residents 0.60 0.09 0.42-0.78 Inter-observer T1 Surgeons vs residents 0.39-0.57 - - Surgeons 0.52 0.13 0.26-0.78 Residents 0.48 0.12 0.24-0.72 Inter-observer T2 Surgeons vs residents 0.30-0.44 - - Surgeons 0.51 0.12 0.27-0.75 Residents 0.48 0.12 0.24-0.72 Table III: Intra- and inter-observer agreement between Mason-Hotchkiss type I (conservati ve) and Mason- 8 Hotchkiss type II+III fractures (surgical treatment). T1 = fi rst observati on, T2 = second observati on, SE = Standard Error. CI = Confi dence Interval. for both the observati on moments. The diff erences were not stati sti cally signifi cant. (Table II) Intra-observer agreement in treatment (conservati ve versus surgical) of the radial head fracture was substanti al, with a κ-value of 0.69. Inter-observer agreement between residents and surgeons varied between 0.39 and 0.57. Inter-observer agreement was 0.48 for residents and 0.51 for surgeons. (Table III) 102 Chapter 8

DISCuSSIOn

Classification systems are of great importance in orthopaedic practice, as they describe fractures, guide treatment and able us to compare outcome of treatment within and between studies. As a result, intra- and inter-observer agreement are important for any classification system.8 In our study the overall inter-observer agreement of the Mason- Hotchkiss was substantial. Inter-observer agreement ranged from 0.27 (fair) to 0.74 (substantial). We observed that experienced surgeons scored a higher (almost perfect) inter-observer agreement, compared to the lower end of substantial agreement between residents. However, this difference is not statistically significant. There are only a few studies on inter- and intra-observer agreement of the Mason- classification and its adaptations, with varying results, ranging from poor to excellent.8-11 This large variety may be caused by the classification modifications. For example: a type II fracture in the original Mason classification is “a marginal sector fracture with displacement”1, but in the Mason-Broberg adaptation3 the amount of displacement and fractures joint surface are more specified, leaving less room for interpretation. Doornberg et al.10 studied the agreement of the Broberg and Morrey modification and concluded that the intra-observer agreement was excellent, and the inter-observer reliability was moderate using the κ-value to measure agreement. However, this study included only radiographs of borderline Mason type I and II fractures. Morgan et al.11 considered the inter and intra- observer agreement of the Mason classification as poor. Matsunaga et al.8 compared the Mason, Mason-Morrey and the AO/ASIF classification systems for radial head fractures, and concluded that the Mason classification and Morrey and Broberg adaptation are the most reliable, with a moderate inter-observer agreement. The results from this study con- firm those found by Sheps et al.9 They concluded that the Mason-Hotchkiss classification inter-observer agreement was moderate, with a κ-value of 0.72. After collapsing Mason type II and type III fractures, inter-observer agreement increased to substantial. The AO/ ASIF classification scored poor on both inter- and intra-observer agreement. We did not include other adaptations of the Mason-classification in this study, so no comparison can be made. When including the results of this study, the Mason-Broberg modification still has the highest reported intra- and intra-observer agreement in literature.10 It is widely used and provides a good description of the amount of displacement and involved joint surface, making this modification a preferable classification for radial head fractures. The differentiation between Mason-Hotchkiss type I and type II fractures is the most challenging as, according to Hotchkiss, here lies the borderline between non-operative and operative treatment.5 Intra-observer agreement for treatment of the radial head fracture in this study is substantial, and inter-observer agreement ranged between fair to moderate. The amount of displacement in isolated type II fractures that requires ORIF is still subject of discussion in literature. Although results of ORIF are generally good14-16, there Intra- and interobserver reliability 103 are reports of sati sfactory results aft er conservati ve treatment of type II fractures with > 2 mm dislocati on. Akesson et al.17 reviewed 49 primary conservati vely treated pati ents with mason type II fractures with 2-5 mm of dislocati on of ≥ 30% of the joint surface. A delayed radial head excision was performed if the early outcome of the non-operati ve treatment is unsati sfactory in 6 pati ents. 48 of 49 pati ents had no or minor elbow complaints aft er a mean follow-up of 19 years. Karlsson et al. even reported no or minor long-term elbow complaints in 18 out of 19 pati ents with a comminuted radial head fracture.18 A new classifi cati on for radial head fractures is indicated as this borderline between conservati ve and surgical treatment becomes clear, based on the results of prospecti ve studies and/or randomised clinical trials.

COnCLuSIOnS

We can state that the inter-observer agreement of the Mason-Hotchkiss classifi cati on for radial head fractures was substanti al and the intra-observer agreement ranged from fair to substanti al. The experienced surgeons scored almost perfect inter-observer agreement, compared to the lower end of substanti al agreement between residents, although this difference was not stati sti cally signifi cant. Intra-observer agreement for surgical or conservati ve treatment of the radial head fracture in this study was substanti al, and inter-observer agreement ranged between fair to moderate.

8 104 Chapter 8

REFEREnCE LIST

(1) Mason ML. Some observations on fractures of the head of the radius with a review of one hundred cases. Br J Surg 1954; 42: 123-132. (2) Johnston GW. A follow-up of one hundred cases of fracture of the head of the radius with a review of the literature. Ulster Med J 1962; 31: 51-56. (3) Broberg MA, Morrey BF. Results of treatment of fracture-dislocations of the elbow. Clin Orthop Relat Res 1987; 216: 109-119. (4) van Riet RP, Morrey BF. Documentation of associated injuries occurring with radial head fracture. Clin Orthop Relat Res 2008; 466: 130-134. (5) Hotchkiss RN. Displaced fractures of the radial head: internal fixation or excision? J Am Acad orthop Surg 1997; 5: 1-10. (6) Martin JS, Marsh JL. Current classification of fractures. Rationale and utility. Radiol Clin North Am 1997; 35: 491-506. (7) Dirschl D, Cannada L. Classification of Fractures. In: Bucholz R, Heckman J, Court-Brown C, (eds): Rockwood and Green’s Fractures in Adults. 6 ed. Philadelphia: Lipincot Williams & Wilkins, 2006: 43-44. (8) Matsunaga FT, Tamaoki MJ, Cordeiro EF, Uehara A, Ikawa MH, Matsumoto MH, et al. Are classifica- tions of proximal radius fractures reproducible? BMC Musculoskelet Disord 2009; 10: 120. (9) Sheps DM, Kiefer KR, Boorman RS, Donaghy J, Lalani A, Walker R, et al. The interobserver reliability of classification systems for radial head fractures: the Hotchkiss modification of the Mason classification and the AO classification systems. Can J Surg 2009; 52: 277-282. (10) Doornberg J, Elsner A, Kloen P, Marti RK, van Dijk CN, Ring D. Apparently isolated partial articular fractures of the radial head: prevalence and reliability of radiographically diagnosed displacement. J Shoulder Elbow Surg 2007; 16: 603-608. (11) Morgan SJ, Groshen SL, Itamura JM, Shankwiler J, Brien WW, Kuschner SH. Reliability evaluation of classifying radial head fractures by the system of Mason. Bull Hosp Jt Dis 1997; 56: 95-98. (12) Cohen J. A coefficient agreement for nominal scales. Educ Psychol Meas 1960; 20: 37-46. (13) Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics 1977; 33: 159-174. (14) Lindenhovius AL, Felsch Q, Ring D, Kloen P. The long-term outcome of open reduction and internal fixation of stable displaced isolated partial articular fractures of the radial head. J Trauma 2009; 67: 143-146. (15) Ring D. Open reduction and internal fixation of fractures of the radial head. Hand Clin 2004; 20: 415-427. (16) Michels F, Pouliart N, Handelberg F. Arthroscopic management of Mason type 2 radial head fractures. Knee Surg Sports Traumatol Arthrosc 2007; 15: 1244-1250. (17) Akesson T, Herbertsson P, Josefsson PO, Hasserius R, Besjakov J, Karlsson MK. Primary nonoperative treatment of moderately displaced two-part fractures of the radial head. J Bone Joint Surg Am 2006; 88: 1909-1914. (18) Karlsson MK, Herbertsson P, Nordqvist A, Besjakov J, Josefsson PO, Hasserius R. Comminuted fractures of the radial head. Acta Orthop 2010; 81: 226-229. Chapter 9 Treatment of Mason type II radial head fractures: a systemati c review.

Laurens Kaas, Peter A.A. Struijs, David Ring, C. Niek van Dijk, Denise Eygendaal

Submitt ed 106 Chapter 9

AbSTRACT

Purpose: There is no consensus on the best treatment of Mason type II fractures without concomitant elbow fractures or dislocation. The aim of this systematic review was to compare the results of operative and non-operative treatment of these injuries.Materials and methods: The databases of Pubmed, EMBASE and Cochrane Library were systemati- cally screened until September 2011 for studies on non-operative or operative treatment of Mason type II fractures. Successful treatment was defined as an excellent or good result according to the Broberg and Morrey, Mayo Elbow Performance Score or Radin score. Exclusion criteria were: duration of follow-up of less than 6 months; an improperly described therapy or a combination of therapies; skeletal immaturity and articles written in non-English language. Results: Among 950 studies, 9 retrospective case series (Level IV) describing 224 patients satisfied our inclusion criteria. Non-operative treatment was successful in 114 of 142 (80%) of patients pooled from the studies (42 to 96% success in individual studies). Open reduction and internal fixation (ORIF) was successful in 93% (76 of 82) patients (81 to 100% success in individual studies). Discussion: Only a few studies with a low level of evidence address the treatment of isolated, displaced, partial articular fractures. The data must be interpreted in light of the fact that many of the case series of ORIF were written to introduce or promote operative techniques. There is a need for sufficiently powered randomized controlled trials. Clinical relevance: There is insufficient evidence to draw firm conclusions on the optimal treatment of stable, isolated partial articular Mason type II fractures. Level of evidence: Level IV. Study type: Therapeutic. Treatment of Mason type II radial head fractures 107

InTRODuCTIOn

Radial head fractures are common with an esti mated incidence of 2.5-2.9 per 10,000 people per year, accounti ng for approximately one third of all elbow fractures.1-3 Several classifi cati ons have been introduced to describe radial head fractures, nearly all derived from the classifi cati on introduced by Mason in 1954.4-8 A Mason type I fracture is a fi ssure or marginal sector fracture without displacement; type II fractures are arti cular fractures involving a part of the head with displacement; comminuted arti cular fractures involving the whole head of the radius are Mason type III fractures.5 Mason did not defi ne or quanti fy displacement. Broberg and Morrey modifi ed Mason’s classifi cati on, quanti fying displacement as 2 millimeters or greater arti cular step or gap and indicati ng that fracture fragments representi ng less than 30% of the arti cular surface should not be considered as type II.8 It is generally agreed that type I fractures can be treated non-operati vely with early mobilizati on.2 However, the best treatment of type II fractures that are not associated with other fractures or ligament injuries (so-called “isolated fractures”) is sti ll debated. Some favour non-operati ve treatment and others favour open reducti on and internal fi xati on (ORIF).9 The aim of this systemati c review was to combine the results of relevant studies on treatment of displaced parti al arti cular radial head fractures without associated elbow dislocati on or other elbow fractures, to inform the debate between operati ve and non- operati ve treatment.

MATERIALS AnD METHODS

This systemati c review was performed using the QUORUM statement for reports of meta- analyses of randomized controlled trials. 10 Search strategy and data sources 9 We have systemati cally screened the electronic databases PubMed (from 1980 unti l Sep- tember 2011), EMBASE and the Cochrane Controlled Trials Register. As main keywords we used the MeSH-terms “radial head” and “fracture OR trauma”, with limits set on humans. Of all the arti cles selected, the reference lists were searched for additi onal arti cles.

Study Selecti on Two reviewers independently assessed all references, abstracts and arti cles for inclusion. Agreement was needed for inclusion of a study. In case of disagreement, the opinion of a third investi gator was decisive. To prevent investi gator bias, scoring of the manuscripts was blinded to author and insti tute. Studies were included if there was a proper descripti on of the treatment for radial head fractures (implant type, surgical technique, rehabilitati on 108 Chapter 9

Variable Point value Motion Degree of flexion (0.2 x arc) 27 Degree of pronation (0. 1 x arc) 6 Degree of supination (0. 1 x arc 7 Strength Normal 20 Mild loss (appreciated but not limiting, 80% of opposite side) 13 Severe loss (limits everyday tasks, disabling) 0 Stability Normal 5 Mild loss (perceived by patient, no limitation) 4 Moderate loss (limits some activity) 2 Severe loss (limits everyday tasks) 0 Pain None 35 Mild (with activity, no medication) 28 Moderate (with or after activity) 15 Severe (at rest, constant medication, disabling) 0 Table I: The Broberg and Morrey elbow score. A score of 95 to 100 points is excellent; 80 to 94 points is good; 60 to 79 points is fair; and 0 to 59 points is poor.11 Points Pain None 45 Mild 30 Moderate 15 Severe 0 Motion arc > 100 degrees 20 50-100 degrees 15 < 50 degrees 5 Stability Stable 10 Moderate instability 5 Gross instability 0 Daily function Comb hair 5 Feed self 5 Hygiene 5 Shirt 5 Shoe 5 Total Maximum 100 Table II: The Mayo Elbow Performance Score. A score > 90 is regarded as excellent, between 75-89 as good, between 60-74 as fair and < 60 is graded as poor.12 Score Description Good Less than 10 degrees of loss of motion in any direction and no pain. Fair Up to 30 degrees of loss of motion in any directions or minor complaints, or both. Poor More than 30 degrees of loss of motion in any direction, major complaints, or both. Table III: The Radin score.13 Treatment of Mason type II radial head fractures 109 methods, immobilisati on, follow-up protocol) and a well-defi ned outcome: the Broberg and Morrey score11 (table I), Mayo Elbow Performance Score (MEPS)12 (table II) or the Radin Score12 (table III). Other inclusion criteria were a fracture classifi cati on according to the Mason classifi cati on or one of its modifi cati ons and separately described results for each Mason type. Exclusion criteria were: durati on of follow-up of less than 6 months; an improperly described therapy or a combinati on of therapies; and skeletal immaturity. Arti cles in other languages than English were excluded. Results of radial head fractures with associated elbow fractures or elbow dislocati on were also excluded. The type of study design, parti cipants’ characteristi cs and details of interventi on were also assessed.

Validity assessment and data extracti on Trials were considered to be valid if they sati sfi ed the inclusion and exclusion criteria and contained suffi cient data for further analysis. The initi al database search identi fi ed 717 potenti al reports. 657 of these reports could be excluded on the ti tle alone, 31 were excluded aft er analysis of the abstract. Twenty studies were excluded aft er analysis of the full text. A total number of 9 studies could be included. A search of the reference list of the included studies did not retrieve any additi onal reports. We did not identi fy any duplicate publicati ons. Pati ent data were extracted for each Mason group as much as possible by two separate reviewers. In case of disagreement, the opinion of a third investi gator was decisive. Adap- tati ons of the Mason-classifi cati on that were used, such as the Hotchkiss adaptati on6 and the Broberg and Morrey8 adaptati on, were reduced to the original Mason classifi cati on. So fractures classifi ed Mason-Hotchkiss type II and Mason-Broberg and Morrey type II fractures were regarded as Mason type II fractures. Successful treatment was defi ned as an excellent or good result at follow-up, according to the Broberg and Morrey score and MEPS, or good according to the Radin score13. Other parameters that were looked for were: range of moti on, subsequent surgery aft er initi al treatment and arthrosis of the elbow joint. 9 Study characteristi cs The level of evidence for each included arti cle was independently graded by two authors according to the adapted “Levels of evidence for primary research questi ons” system, as used by the JHS (A).14 In case of disagreement, the opinion of a third investi gator was decisive. All included studies were retrospecti ve case series (Level IV).

S t a ti s ti cs The Chi-square test (or Fisher’s exact test) was used for comparing the rate of success between the treatment groups aft er consultati on of a biostati sti cian. A P-value below 0.05 was considered to be signifi cant. Other data of the included studies were not pooled or 110 Chapter 9

compared: these data (for example patients’ characteristics, development of arthrosis, range of motion, pain and mechanical blockage) were missing or presented in different ways.

RESuLTS

A total of 9 retrospective case series (Level IV) could be included, describing 444 patients, of which data were extracted of 224 patients that met the inclusion criteria. We were not able to provide patients (mean) age, sex, and follow-up period for the included patients of each included study, so the means of all patients described in each study were used in this study. Non-operative treatment consisted of immediate active mobilization or cast immobilization for 1-3 weeks. Four studies report on non-operative treatment of type II radial head fractures. Success was documented in 114 of 142 (80%) of patients pooled from the studies (42 to 96% success in individual studies). Subsequent operative treatment after failed non-operative treatment was reported in 3 patients (2.1%). The results of ORIF were described in 7 studies including 82 patients. Success was documented in 93% (76 of 82) patients (81 to 100% success in individual studies). Revision surgery was reported in 4 patients (4.8%). Presence of arthrosis and subsequently operative treatment were not reported in all of the included studies. The rate of success was significantly higher in the ORIF group, compared to the non-operative group (P = 0.01). Detailed results of all studies can be found in table IV.15-21

DISCuSSIOn

Firm conclusions cannot be drawn from this systematic review, as they are all retrospective studies, with a low level of evidence, small patient numbers and a large heterogeneity in study design and results. Important data regarding development of arthrosis, range of motion, pain and mechanical blockage retrieved from the included studies are missing or presented in different ways. This, combined with the wide variety in classification systems, treatments, and outcome measures makes it difficult to compare results between studies. The mean range of motion was decreased in all directions after operative ornon- operative treatment (table IV). However, a full range of motion is not essential for performance of all the activities of daily living. The functional arc of flexion and extension about which most daily activities are performed is 30 to 130 degrees, and 50 degrees of pro- and supination are required to perform 90% of daily activities.22 So, if for example surgical treatment leads to a better range of motion, it might well be that this increase does not have any functional consequences. The follow-up period of most of the included studies Treatment of Mason type II radial head fractures 111 - - 2 (UH) 16 (NS) - 1 (NS) - - 1 (NS) 3 (NS) - - - Arthrosis 0 - 2 - 1 Subsequent Subsequent ve operati treatment # # 179 166 # # - ROM MEPS Flex Ext Pro Sup ROM provided in mean range of fl exion and extension/pro- extension/pro- exion and of fl in mean range provided ROM # Morrey 114/142 (80.3%)* - 76/82 (92.7%)* Radin Broberg- Success rates 121 - - 75/78 139 121 - - 2/2 - - - - 0 10 - - 8/9 130 -11 81 66 1 number of excluded ents pati 11.3) Mean follow-up in years (range) Mean age in years (range)

Men/ women 9 of ents pati in study - - 1992 261981 391966 17/9 882011 - 201 39 (21-77) 1.5 (0.5-7.8) 39/49 0 94/107 47 (24-75) - (14-77)2010 44 (16-83) > 2 21 1 10 (1-22)1995 - 20 52008 14/7 19 74 - 7/16 36 (25-58)1992 2.6 (0.9-6.7) 26 12/7 26/34 02008 - 6/14 16 - 29 (14-57) 37 (19-78)2007 17/9 7 (1-14) - 6.7 (1.9- 14 1292011 9/7 - - 6 201 39 (21-77) 10 - 1.5 (0.5-7.8) 5/9 76 16 - 39 (17-54) 94/107 59% full ROM 1.8 (1.2-2.5) 19/21 78 44 (16-83) 0 38 (19-57) - - 2 1 5.5 (1-11.3) - - 0 - 10/10 132 - -2 10/10 - - - - 73 13/16 - 142 72 -1 - 136 14/14 - 0 - 16 88 - 78 129 87 78 142 0 1 -3 - - 0 9 17 17 15 15 21 20 18 16 13 19 Combined results Michels Miller Duckworth Esser Givissis Khalfayan Lindenhovius Duckworth Combined results Radin Khalfayan ORIF Ertürer Treatment Author year number review for this excluded study ents of each pati studies. The number of IV Level ve, retrospecti of the included ents of all pati and results data Demographic IV: Table ned as defi are rates Success treated. ents number of pati total to the compared treatment with successful ents in the number of pati given are Results provided. are ve and surgical of non-operati Combined results the Radin score. to according and MEPS, or good and Morrey the Broberg to according result, or good an excellent on. on/supinati fl exion/extension/pronati in mean provided on (ROM) of moti Range provided. are treatment and supinati on. Subsequent operati ve treatment: number of pati ents that underwent surgery aft er failed non-operati ve treatment or re-surgery aft er primary surgery. surgery. aft er primary or re-surgery treatment ve er failed non-operati aft surgery that underwent ents pati number of treatment: ve operati on. Subsequent and supinati ed. *P=0.01. not specifi NS = type of arthrosis arthrosis. UH = ulnuhumeral follow-up. er aft of the elbow with arthrosis ents Number of pati Arthrosis: Non- ve operati 112 Chapter 9

was too short to determine a difference in degenerative changes of the elbow joint for both treatments. Although the success rate of operative treatment is significantly higher compared to non-operative treatment (80.3 vs. 92.7%), there are too many variables, such as period of immobilization and follow-up period, within and between treatment groups to claim that operative treatment provides the best results. In order to obtain comparable results from individual studies for this systematic review, the Mason-Broberg and Mason-Hotchkiss adaptations of the Mason classification were reduced to the original Mason classification. However, some Broberg and Morrey or Hotchkiss type I fractures would be considered a type II fracture in the Mason classification. We were not able to review the radiographs of the included studies for the degree of displacement and percentage of radial head involvement. We also had to make assump- tions regarding to the sex, age and follow-up of the Mason type II fractures because many papers did not provide separate data. In these cases we provided the data of the entire study cohort of the study, which also included other Mason type fractures and fractures with associated injuries. Presence of associated fractures or ligament injuries was not well described and has not clearly been distinguished in all of the included studies. A strong correlation between the likelihood of associated injury and absence of cortical contact of the radial head fragments (unstable radial head fractures) has been described by Rineer et al.23 Isolated, displaced fractures are not only difficult to define and diagnose, they are relatively uncommon and may not be reliably identified.24 The relative infrequency of these issues as well as incon- sistency in what various observers feel merits the diagnosis of “displacement” make these fractures difficult to study and the reported data difficult to interpret.24-26 Studies describing the results of ORIF should be interpreted in light of the fact that many of them were written to report on a new implant and/or technique for ORIF of displaced partial articular radial head fractures. These studies could be considered introductory and promotional and subject to bias and the tendency for initially positive results to become less positive or even neutral or reversed as additional experiments are done, due to result of regression to the mean, sampling error, and publication bias among other factors). There is still room for debate about the indications for surgery and the relative risks and benefits compared to non-operative treatment of Mason type II radial head fractures. Herbertsson et al.27 and Akesson et al.3 reported good long term results with non-operative treatment Mason type II radial head fractures after a mean follow-up of 19 years. Both studies were excluded from this review because of absence of one of the selected outcome measures and/or inclusion of patients with associated fractures, without providing separate results. To inform the debate between operative and non-operative treatment of displaced but stable, isolated partial articular fractures of the radial head we need prospective, randomized, control trials comparing the two treatment strategies. To ensure that the results of these trials can be generalized to the average patient and the average surgeon we need Treatment of Mason type II radial head fractures 113 clear defi niti ons as well as reliable and accurate methods for diagnosing and quanti fying displacement and associated injuries. Rather than physician based overall scoring systems, we should study fi nal forearm moti on and arm specifi c disability. In conclusion, we can state that there is insuffi cient evidence to draw fi rm conclusions on the opti mal treatment of stable isolated parti al arti cular Mason type II fractures. Only a few studies with a low level of evidence address the treatment of isolated, displaced, parti al arti cular fractures.

9 114 Chapter 9

REFEREnCE LIST

(1) Kaas L, van Riet RP, Vroemen J, Eygendaal D. The epidemiology of radial head fractures. J Shoulder Elbow Surg 2010 Jun 1; 19(4): 520-3. (2) van Riet RP, van Glabbeek F, Morrey BF. Radial Head Fracture: General Considerations, Conservative Treatment and Open Reduction and Internal Fixation. In: Morrey B, Sanchez-Sotelo J, editors. The Elbow and its Disorders. 4 ed. Philadelphia: Saunders; 2009. p. 359-81. (3) Akesson T, Herbertsson P, Josefsson PO, Hasserius R, Besjakov J, Karlsson MK. Primary nonoperative treatment of moderately displaced two-part fractures of the radial head. J Bone Joint Surg Am 2006 Sep; 88(9): 1909-14. (4) van Riet RP, Morrey BF. Documentation of associated injuries occurring with radial head fracture. Clin Orthop Relat Res 2008 Jan; 466(1): 130-4. (5) Mason ML. Some observations on fractures of the head of the radius with a review of one hundred cases. Br J Surg 1954; 42: 123-32. (6) Hotchkiss RN. Displaced fractures of the radial head: internal fixation or excision? J Am Acad orthop Surg 1997; 5: 1-10. (7) JOHNSTON GW. A follow-up of one hundred cases of fracture of the head of the radius with a review of the literature. Ulster Med J 1962 Jun 1; 31: 51-6. (8) Broberg MA, Morrey BF. Results of delayed excision of the radial head after fracture. J Bone Joint Surg Am 1986 Jun; 68(5): 669-74. (9) Lindenhovius AL, Felsch Q, Ring D, Kloen P. The long-term outcome of open reduction and internal fixation of stable displaced isolated partial articular fractures of the radial head. J Trauma 2009 Jul; 67(1): 143-6. (10) Moher D, Cook DJ, Eastwood S, Olkin I, Rennie D, Stroup DF. Improving the quality of reports of meta-analyses of randomised controlled trials: the QUOROM statement. Quality of Reporting of Meta-analyses. Lancet 1999 Nov 27; 354(9193): 1896-900. (11) Broberg MA, Morrey BF. Results of treatment of fracture-dislocations of the elbow. Clin Orthop Relat Res 1987 Mar; (216): 109-19. (12) Morrey BF, Adams RA. Semiconstrained arthroplasty for the treatment of rheumatoid arthritis of the elbow. J Bone Joint Surg Am 1992 Apr; 74(4): 479-90. (13) Radin EL, Riseborough EJ. Fractures of the radial head. A review of eighty-eight cases and analysis of the indications for excision of the radial head and non-operative treatment. J Bone Joint Surg Am 1966 Sep; 48(6): 1055-64. (14) http: //www.jhandsurg.org/authorinfo. Last update: november 2011. (15) Khalfayan EE, Culp RW, Alexander AH. Mason type II radial head fractures: operative versus nonoperative treatment. J Orthop Trauma 1992; 6(3): 283-9. (16) Miller GK, Drennan DB, Maylahn DJ. Treatment of displaced segmental radial-head fractures. Long- term follow-up. J Bone Joint Surg Am 1981 Jun; 63(5): 712-7. (17) Duckworth AD, Watson BS, Will EM, Petrisor BA, Walmsley PJ, Court-Brown CM, et al. Radial Head and Neck Fractures: Functional Results and Predictors of Outcome. J Trauma 2011 Jan 18. (18) Erturer E, Seckin F, Akman S, Toker S, Sari S, Ozturk I. The results of open reduction and screw or K-wire fixation for isolated type II radial head fractures. Acta Orthop Traumatol Turc 2010; 44(1): 20-6. (19) Esser RD, Davis S, Taavao T. Fractures of the radial head treated by internal fixation: late results in 26 cases. J Orthop Trauma 1995; 9(4): 318-23. Treatment of Mason type II radial head fractures 115

(20) Givissis PK, Symeonidis PD, Ditsios KT, Dionellis PS, Christodoulou AG. Late results of absorbable pin fi xati on in the treatment of radial head fractures. Clin Orthop Relat Res 2008 May; 466(5): 1217-24. (21) Michels F, Pouliart N, Handelberg F. Arthroscopic management of Mason type 2 radial head fractures. Knee Surg Sports Traumatol Arthrosc 2007 Oct;15(10): 1244-50. (22) Regan WD, Morrey BF. Physical examinati on of the elbow. In: Morrey BF, Sanches-Sotelo J, editors. The Elbow and Its Disorders. 4 ed. Philadelphia: Saunders-Elsevier; 2009. p. 67-79. (23) Rineer CA, Guitt on TG, Ring D. Radial head fractures: Loss of corti cal contact is associated with concomitant fracture or dislocati on. J Shoulder Elbow Surg 2010 Jan 1; 19(1): 21-5. (24) Doornberg J, Elsner A, Kloen P, Marti RK, van Dijk CN, Ring D. Apparently isolated parti al arti cular fractures of the radial head: prevalence and reliability of radiographically diagnosed displacement. J Shoulder Elbow Surg 2007 Sep;16(5): 603-8. (25) Sheps DM, Kiefer KR, Boorman RS, Donaghy J, Lalani A, Walker R, et al. The interobserver reliability of classifi cati on systems for radial head fractures: the Hotchkiss modifi cati on of the Mason classifi cati on and the AO classifi cati on systems. Can J Surg 2009 Aug; 52(4): 277-82. (26) Matsunaga FT, Tamaoki MJ, Cordeiro EF, Uehara A, Ikawa MH, Matsumoto MH, et al. Are classifi cati ons of proximal radius fractures reproducible? BMC Musculoskelet Disord 2009; 10: 120. (27) Herbertsson P, Josefsson PO, Hasserius R, Karlsson C, Besjakov J, Karlsson M. Uncomplicated Mason type-II and III fractures of the radial head and neck in adults. A long-term follow-up study. J Bone Joint Surg Am 2004 Mar;86-A(3): 569-74.

Chapter 10 Results of the cemented and press-fit bipolar radial head prosthesis in 33 elbows with a minimal follow-up of 2 years

Laurens Kaas, Roger P. van Riet, C. Niek van Dijk, Denise Eygendaal

Submitted 118 Chapter 10

AbSTRACT

Introduction: The bipolar Judet radial head prosthesis can be used in unreconstructable, comminuted radial head fractures and is available in two types: cemented and press-fit. The goal of this study was to describe the results of both implant types. Patients and methods: 33 patients with a Judet prosthesis (17 cemented, 16 press-fit) were retrospectively reviewed, with a median follow-up of 33 (range: 24-62) months. Results: Nineteen patients scored excellent, 10 scored good, 1 fair and 3 poor on the Mayo Elbow Perfor- mance Index, with a median of 100. The median Elbow Function Assessment score was 94. The median functional range of motion was 130° (range: 80°-145°). Median supination was 70° and median pronation also 70.0°. Complications occurred in 13 elbows. Eleven of the 16 elbows with a press-fit implant showed osteolysis proximal radius. In the cemented implant group periprosthetic lucencies were found in 2 of 19 patients. Discussion: The short-term functional results of the Judet radial head prosthesis are good or excellent in 88% of the cases. Osteolysis of the proximal radius was found in the majority patients with a press-fit prosthesis, without any impact on the clinical outcome. The exact cause and clinical implications of this osteolysis requires further investigation. Level of evidence: Level IV. Key words: Radial head, fracture, bipolar prosthesis, press-fit, cemented, elbow, trauma. Results of a bipolar radial head prosthesis 119

InTRODuCTIOn

Radial head prostheses are available in two broad designs: unipolar implants1-3 and bipolar prostheses.4 Bipolar radial head prostheses have a symmetric head, that arti culates in a semiconstrained fashion with a fi xed stem. The rati onale of this design, is that the additi onal freedom of movement reduces stress at the implant-bone interface and increases the contact area at the radiocapitellar joint.4, 5 Moreover, in reconstructi on of longstanding postt raumati c deformiti es, malalignment of the proximal radius in relati on to the capitellum can be overcome by the bipolar design.6 The fl oati ng radial head prosthesis is a bipolar prosthesis and is available in two types: a long-stemmed cemented prosthesis with an stem/neck angle of 15 degrees and short-stemmed press-fi t prosthesis. The press-fi t system possibly allows easier revision, which may be required in young, demanding pati ents and it is easier to insert, as the stem is shorter and straight. To our knowledge no results of the more recent, press-fi t bipolar fl oati ng radial head prosthesis have been published. The goal of this retrospecti ve study was to describe the results of the cemented and press-fi t fl oati ng radial head prosthesis in pati ents with post traumati c disorders of the elbow aft er a radial head fracture.

PATIEnTS AnD METHODS

Pati ents Data of all 34 pati ents, 13 male and 21 female, in which a bipolar radial head prosthesis was implanted in the period between March 2005 and July 2009 were retrospecti vely reviewed. One pati ent was lost to follow-up and was excluded for analysis: a seasonal worker who was treated for a posterolateral elbow dislocati on, with a Mason-Mayo type III fracture and a lateral collateral ligament rupture (LCL). The median age of the remaining 33 pati ents available for follow-up was 52 (range: 24-70) years. The dominant side was aff ected in 19 cases. Twelve pati ents were treated with an un-reconstructable radial head fracture within three weeks aft er trauma, which were considered to be acute. Associated injuries were present in 9 of these pati ents. Sixteen pati ents had failed previous surgery to the radial head, such as radial head excision, ORIF or radial head arthroplasty. Delayed 10 surgery aft er failed initi al conservati ve treatment was performed in 7 pati ents.

Implant The implant used in these pati ents (RHS, Tornier SA, Saint-Ismier, France) is in two parts: the head is made from high-density poly-ethylene (PE) encased in cobalt-chrome, which arti culates in a semi-constrained manner with the spherical end of a cemented cobalt- chrome intramedullary stem. Half-way the selected period the short stem uncemented 120 Chapter 10

Cemented (n=17) Press-fit (n=16) Total (n=33) Age (years) 53 (36-70) 52 (24-61) 52 (24-70) Sex (male/female) 6/11 6/10 12/21 Dominance 8 11 19 Follow-up (months) 36 (25-62)* 28 (24-40)* 33 (24-62) Indication for Acute trauma 6 6 12 surgery Failed conservative 3 2 5 Revision surgery 8 8 16 Complications 7 6 13 MEPI 100 90 100 (range) (55-100) (60-100) (55-100) EFA 95 93 94 (range) (76-100) (60-100) (76-100) Table I: Summary of patient group characteristics, complications and functional results after follow-up. MEPI = Mayo Elbow Performance Index. EFA = Elbow Function Assessment score. * = statistically significant difference (P = 0.01).

prosthesis was introduced. The switch to the press-fit implant was made for several reasons: in literature reported periprosthetic radiolucencies of the proximal radius7; the short, straight stem allows easier implantation in the curved proximal radius; potentially allows easier revision; and operating time is reduced. In 17 patients a cemented prosthesis was implanted and 16 patients received a press-fit prosthesis. Patient characteristics for both groups were similar, except for follow-up, which was significantly longer for cemented implants (Table I).

Surgical procedures and rehabilitation 31 of 33 patients were treated by a single experienced elbow surgeon, the other two patients were treated by an experienced traumatologist. The radial head was exposed through a posterolateral Kocher incision. In 27 patients adjuvant surgical procedures were performed, such as collateral ligament reconstruction, arthrolysis and osteosynthesis of associated fractures of the elbow. Postoperatively, 28 patients performed active assisted motion exercises with the help of a physiotherapist. After 6 weeks, active and passive stretching was allowed and strengthening exercises were started. An elbow cast because of severe post-operative swelling was applied for 1 to 3 weeks postoperatively in 5 patients, before mobilization was allowed.

Follow-up Range of motion (ROM), varus and valgus stability and the pivot shift test were evaluated before surgery (except for acute patients) and during the regular follow-up at 6 months after surgery and yearly follow-up. Elbow function was evaluated with use of the Mayo Elbow Performance Index (MEPI)8 and Elbow Function Assessment (EFA) scale.9 Post-operative Results of a bipolar radial head prosthesis 121

Grade Descripti on 0 Normal elbow I Slight joint-space narrowing with minimum osteophyte formati on II Moderate joint-space narrowing with moderate osteophyte formati on III Severe degerenati ve changes with gross joint destructi on Table II: Broberg and Morrey classifi cati on for degenerati ve changes of the elbow joint.11

Complicati on Wound Instability Persistent Overstuffi ng Revision Implant infecti on pain surgery removal Implant Cemented 1 5 2 2 1 2 type Press-fi t 0 5 1 0 2 0 Total 1 10 3 2 3 2 Table III: Number and types of complicati ons occurred.

Figure 1: The seven delineated secti ons around the radial component for zonal evaluati on of radiographic changes, as introduced by Popovic et al.7 (reproduced with permission) complicati ons were noted. Evaluati on of standard anteroposterior (AP) and lateral elbow 10 radiographs consisted of assessment and quanti fi cati on of periarti cular ossifying disease (PAOD) according to the Hasti ngs and Graham classifi cati on10, and degenerati ve changes according to the Broberg and Morrey classifi cati on (table II).11 Changes of the proximal radius (including radiolucent lines and osteolysis of the proximal radius) for cemented implants were classifi ed, according to the method previously described by Popovic et al.7, dividing the proximal radius into seven zones (fi gure 1). For the press-fi t implants a 122 Chapter 10

Figure 2: Adaptation for press-fit implants to categorize lucency on radiographs, as introduced by Grewal et al.12 (reproduced with permission)

modification of this classification was used12, as the stem of this design is much shorter (figure 2). Ulnohumeral joint space, capitellar osteopenia and erosion were also assessed.

Statistical analysis Statistical analysis was performed using SPSS 16.0 (SPSS, Chicago, Il). The Chi-square test (or Fishers exact test) was used for comparing dichotomous values of baseline characteristics. The Mann-Whitney U test was performed for small sample sizes and skewed distributions. In case of skewed distribution, a median was provided instead of a mean. A P-value below 0.05 was considered to be a significant result.

RESuLTS

The median follow-up of all patients was 33 (range: 24-62) months. The median MEPI was 100 (range: 55-100) points. Nineteen patients scored excellent, 10 scored good, 1 fair and 3 poor. The median EFA was 94 (range: 60-100) points. Median elbow flexion was 140° (range: 120-150), with a median extension deficit of 5° (range:0-50). Median supination was 70° (range: 20-90) and pronation 70.0° (range 30-90). The median functional range of motion was 130° (range: 80°-145°). Separate results of the cemented and the press-fit prosthesis are provided in table I. One or more complications (symptomatic instability, persistent pain, wound infection, revision surgery, overstuffing) occurred in a total of 13 patients (7 cemented and 6 press-fit) (table III). Radiological assessment showed no periprosthetic fractures. Four patients had a PAOD with radiographical assessment, of which it was present before surgery in 2 patients. The other 2 patients developed a grade I PAOD Results of a bipolar radial head prosthesis 123

Radiological fi ndings Cemented (n=17) Press-fi t (n=16) Total (n=33) PAOD 1 3 4 Degenerati ve arthriti s 8 7 15 Osteopenia lateral condyle 7 3 10 Erosion of capitellum 0 1 1 Radioluscence around stem 1 0 1 Osteolysis proximal radius 1 11 12 Overstuffi ng 2 0 2 Table IV: Summary of radiological fi ndings aft er follow-up. PAOD: periarti cular ossifying disease.

Figure 3: A right elbow 14 months aft er radial head replacement surgery. Note the evident osteolysis of the proximal radius (arrow 1 and 2) and the osteopenia of the capitellum (arrow 3).

(no limitati on of moti on). Post-traumati c degenerati ve osteoarthriti s of the elbow joint was seen in 15 elbows: 10 pati ents had a Broberg and Morrey grade II, of which 4 were progressive. A grade I osteoarthriti s was seen in 3 pati ents. Two pati ents had a stable pre- existent grade III osteoarthriti s. Overstuffi ng was found in 2 pati ents, and both pati ents 10 had progressive grade II degenerati ve osteoarthriti s of the elbow and 1 had capitellar erosion. Osteopenia of the capitellum or lateral condyle was seen in 10 elbows, of which 8 pati ents developed osteopenia aft er radial head implantati on (fi gure 3). Radiographic changes of the proximal radius were seen in 13 pati ents. Eleven of the 16 elbows with a press-fi t implant showed osteolysis of the cortex distal to the collar of the implant in zone 1 and/or 7 (fi gure 3), compared to only 1 in the cemented group. In the cemented implant 124 Chapter 10

group periprosthetic (balloon-shaped) lucencies in a variety of zones around the stem were found in 1 of 19 patients. Radiographic findings are summarised in table .IV

DISCuSSIOn

Several case series on the clinical results of the cemented bipolar Judet radial head implant have been published over the past years. To our knowledge, this is the first report in which results of the press-fit bipolar Judet radial head implants are presented. Our results of both implants are comparable to those reported in the literature for the cemented bipolar implant: success rates (with functional scores of good to excellent) range from 67% to 100%4, 7, 13-20, compared to 88% in this series. However, a good comparison is difficult, as the included patient characteristics, like type of injury, associated injuries and revision surgery highly vary between studies. The number of patients with revision surgery is high in our case series, which might cause the relatively high number of complications in our series. We did not compare the results of the cemented implant versus the press-fit implant, as there was a large difference in duration of follow-up. No dislocation of the prosthesis head, which has been described in several case reports, was seen in this series.6, 21, 22 Periprosthetic (balloon-shaped) lucencies in a variety of zones, around the stem was found in 1 of 19 patients with a cemented implant (figure 4). Popovic et al.7 described three different types of radiographic changes around the prosthetic stem in their report on results of the cemented bipolar Judet prosthesis: complete or incomplete radiolucent

Figure 4: Balloon shaped osteolysis (arrows) of the proximal radius in zone 1 and 7 after implantation of a cemented bipolar Judet prosthesis 18 months after surgery. Results of a bipolar radial head prosthesis 125 lines, balloon-shaped radiolucent zones, and proximal bone resorpti on at the radial neck. 53% of their 51 elbows had radiographic evidence of periprostheti c lucency within the medullary canal of the radius aft er a mean follow-up of 8.4 years. They state that this could be caused by PE wear or an altered load transmission. However, these results are not confi rmed by other studies: Burkhardt et al.13 state that the results by Popovic et al. can be explained by insuffi cient cementi ng techniques, as they did not fi nd any osteolysis of the proximal radius in their series of 19 cemented Judet prosthesis with a follow-up of 8.8 years. It is also less frequently (0 to 6.3%) described in other available studies with short to medium-term follow-up.14, 16, 20, 23 In our study, proximal osteolysis in the cemented group was caused by an insuffi cient cementi ng technique in at least 1 elbow. Eleven of our 16 pati ents (69%) with a press-fi t implant had parti al or complete osteolysis with corti cal atrophy of the proximal radius (zones 1 and 7), whereas the distal end of the prosthesis remained rigidly fi xed in the bone. A possible cause this osteolysis can be wear of the PE: histological evidence of PE wear in bipolar implants was reported by O’Driscoll and Herald.22 However, it is unlikely as the mean follow-up period of these pati ents (29.5 months) is too short to cause signifi cant wear debris and it was not seen in the elbows with a cemented implant, of which the mean follow-up period was signifi cantly longer (39.2 months). In our opinion it is highly likely that stress shielding is the most important factor for the osteolysis of the proximal radius in the press-fi t group: The short, thick, and hence more rigid stem of the press-fi t design is more prone to stress shielding, compared to the long, thinner and likewise more fl exible stem of the cemented implant.24 Furthermore, Chanlalit et al.25 recently reported of “many cases” of proximal osteolysis in non-cemented Anatomic Radial Head implants (Acumed, Hillsboro, OR), which they also att ribute to stress shielding. The clinical relevance of the proximal osteolysis is unknown, but may eventually lead to failure of the implant. The bone loss of the proximal radius will also make a revision of the implant diffi cult. We advise regular radiographic control for the pati ents with a press-fi t Judet prosthesis and medium- and long-term reports on the press-fi t design are in demand to assess the clinical relevance of this radiographic fi nding. Asymptomati c osteopenia of the capitellum and/or lateral humeral condyle was seen in 10 of 33 elbows. This osteopenia might be caused by a decreased load through the capitellum and has been reported aft er radial head resecti on and radial head arthroplasty.26-28 As it does not occur in all elbows aft er radial head replacement, mechanical factors like 10 understuffi ng or subsidence of the implant might play a role.29 Remission of the osteopenia was observed in 1 post-radial head excision elbow aft er radial head replacement, possibly aft er restoring the normal load patt ern aft er implantati on of the prosthesis. Moro et al. reported asymptomati c capitellar osteopenia in 78% of 24 pati ents with a metal spacer aft er a mean follow-up of 39 months.28 Popovic et al.7, Celli et al.14 and Burkhart et al.13 do not report on capitellar osteopenia in their case series of the Judet prosthesis. Although many pati ents with capitellar osteopenia remain asymptomati c, it can have clinical implicati ons: 126 Chapter 10

van Riet et al.27 report on capitellar erosion after radial head replacement in a patient with capitellar osteopenia and overstuffing. Weaknesses of this study are the retrospective character of this case series, the variety in indications for radial head replacement, and the two different designs used. However, we believe that despite these weaknesses important conclusions can be drawn from this study:.

COnCLuSIOnS

The functional results of the Judet radial head prosthesis, cemented and press-fit, are good or excellent in 88% of the cases. The number of patients with revision surgery is high in our case series, which might cause the relatively high number of complications in our series. Osteolysis of the proximal radius was found in the majority patients with a press- fit prosthesis. The exact cause and clinical implication of this osteolysis requires further investigation. Careful follow-up of these implants is indicated. Results of a bipolar radial head prosthesis 127

REFEREnCE LIST

(1) King GJ, Patt erson SD. Metallic radial head arthroplasty. Tech Hand Up Extrem Surg 2001 Dec; 5(4): 196-203. (2) Doornberg JN, Parisien R, van Duijn PJ, Ring D. Radial head arthroplasty with a modular metal spacer to treat acute traumati c elbow instability. J Bone Joint Surg Am 2007 May; 89(5): 1075-80. (3) Harrington IJ, Sekyi-Otu A, Barrington TW, Evans DC, Tuli V. The functi onal outcome with metallic radial head implants in the treatment of unstable elbow fractures: a long-term review. J Trauma 2001 Jan;50(1): 46-52. (4) Judet T, Garreau de LC, Piriou P, Charnley G. A fl oati ng prosthesis for radial-head fractures. J Bone Joint Surg Br 1996 Mar;78(2): 244-9. (5) Moungondo F, El Kazzi W., Van RR, Feipel V, Rooze M, Schuind F. Radiocapitellar joint contacts aft er bipolar radial head arthroplasty. J Shoulder Elbow Surg 2010 Mar;19(2): 230-5. (6) van Riet RP, Sanchez-Sotelo J, Morrey BF. Failure of metal radial head replacement. J Bone Joint Surg Br 2010 May;92(5): 661-7. (7) Popovic N, Lemaire R, Georis P, Gillet P. Midterm results with a bipolar radial head prosthesis: radiographic evidence of loosening at the bone-cement interface. J Bone Joint Surg Am 2007 Nov; 89(11):2469-76. (8) Morrey BF, Adams RA. Semiconstrained arthroplasty for the treatment of rheumatoid arthriti s of the elbow. J Bone Joint Surg Am 1992 Apr;74(4): 479-90. (9) de Boer YA, van den Ende CH, Eygendaal D, Jolie IM, Hazes JM, Rozing PM. Clinical reliability and validity of elbow functi onal assessment in rheumatoid arthriti s. J Rheumatol 1999 Sep; 26(9): 1909- 17. (10) Hasti ngs H, Graham TJ. The classifi cati on and treatment of heterotopic ossifi cati on about the elbow and forearm. Hand Clin 1994 Aug;10(3): 417-37. (11) Broberg MA, Morrey BF. Results of treatment of fracture-dislocati ons of the elbow. Clin Orthop Relat Res 1987 Mar;(216): 109-19. (12) Grewal R, MacDermid JC, Faber KJ, Drosdowech DS, King GJ. Comminuted radial head fractures treated with a modular metallic radial head arthroplasty. Study of outcomes. J Bone Joint Surg Am 2006 Oct;88(10): 2192-200. (13) Burkhart KJ, Matt yasovszky SG, Runkel M, Schwarz C, Kuchle R, Hessmann MH, et al. Mid- to long- term results aft er bipolar radial head arthroplasty. J Shoulder Elbow Surg 2010 Oct; 19(7): 965-72. (14) Celli A, Modena F, Celli L. The acute bipolar radial head replacement for isolated unreconstructable fractures of the radial head. Musculoskelet Surg 2010 May;94 Suppl 1:S3-S9. (15) Holmenschlager F, Halm JP, Winckler S. [Fresh fractures of the radial head: results with the Judet prosthesis]. Rev Chir Orthop Reparatrice Appar Mot 2002 Jun;88(4): 387-97. (16) Muller MC, Burger C, Striepens N, Wirtz CD, Weber O. [Clinical results aft er replacement of comminuted radial head fractures (Mason III and IV) by the bipolar radial head prosthesis of Judet]. Z 10 Orthop Unfall 2008 Mar;146(2): 218-26. (17) Dotzis A, Cochu G, Mabit C, Charissoux JL, Arnaud JP. Comminuted fractures of the radial head treated by the Judet fl oati ng radial head prosthesis. J Bone Joint Surg Br 2006 Jun; 88(6): 760-4. (18) Ruan HJ, Fan CY, Liu JJ, Zeng BF. A comparati ve study of internal fi xati on and prosthesis replacement for radial head fractures of Mason type III. Int Orthop 2009 Feb;33(1): 249-53. (19) Smets S, Govaers K, Jansen N, Van RR, Schaap M, van GF. The fl oati ng radial head prosthesis for comminuted radial head fractures: a multi centric study. Acta Orthop Belg 2000 Oct; 66(4): 353-8. 128 Chapter 10

(20) Brinkman JM, Rahusen FT, de Vos MJ, Eygendaal D. Treatment of sequelae of radial head fractures with a bipolar radial head prosthesis: good outcome after 1-4 years follow-up in 11 patients. Acta Orthop 2005 Dec; 76(6): 867-72. (21) Herald J, O’Driscoll S. Complete dissociation of a bipolar radial head prosthesis: a case report. J Shoulder Elbow Surg 2008 Nov; 17(6): e22-e23. (22) O’Driscoll SW, Herald J. Symptomatic failure of snap-on bipolar radial head prosthesis. J Shoulder Elbow Surg 2009 Sep; 18(5): e7-11. (23) Holmenschlager F, Halm JP, Piatek S, Schubert S, Winckler S. [Comminuted radial head fractures. Initial experiences with a Judet radial head prosthesis]. Unfallchirurg 2002 Apr; 105(4): 344-52. (24) Huiskes R, Weinans H, Van RB. The relationship between stress shielding and bone resorption around total hip stems and the effects of flexible materials. Clin Orthop Relat Res 1992 Jan; (274): 124-34. (25) Chanlalit C, Shukla DR, Fitzsimmons JS, Thoreson AR, An KN, O’Driscoll SW. Radiocapitellar stability: the effect of soft tissue integrity on bipolar versus monopolar radial head prostheses. J Shoulder Elbow Surg 2011 Mar; 20(2): 219-25. (26) Janssen RP, Vegter J. Resection of the radial head after Mason type-III fractures of the elbow: follow-up at 16 to 30 years. J Bone Joint Surg Br 1998 Mar; 80(2): 231-3. (27) van Riet RP, van GF, Verborgt O, Gielen J. Capitellar erosion caused by a metal radial head prosthesis. A case report. J Bone Joint Surg Am 2004 May; 86-A(5): 1061-4. (28) Moro JK, Werier J, MacDermid JC, Patterson SD, King GJ. Arthroplasty with a metal radial head for unreconstructible fractures of the radial head. J Bone Joint Surg Am 2001 Aug; 83-A(8): 1201-11. (29) van GF, van Riet RP, Baumfeld JA, Neale PG, O’Driscoll SW, Morrey BF, et al. Detrimental effects of overstuffing or understuffing with a radial head replacement in the medial collateral-ligament deficient elbow. J Bone Joint Surg Am 2004 Dec; 86-A(12): 2629-35. Part V General discussion, summary and conclusions

Chapter 11 General discussion and summary

Laurens Kaas 132 Chapter 11

Introduction Radial head fractures are common and account for up to one third of all elbow fractures,1 and were probably first described by Paul of Aegina (AD: 625-690).2 In 1935, Jones already stated that: “The fracture of the head of the radius is a serious injury, and whilst the prognosis is good for recovery of a useful elbow, rarely it is a normal elbow.”3 Although knowledge of radial head fractures has increased over the past few decades, many aspects of this common fracture are still not clear. This thesis contains four parts, in each of which an issue relating to radial head fractures was discussed. In part I elbow anatomy, etiology, diagnosis and treatment of radial head fractures were addressed. The epidemiology of radial head fractures and their associated osseous injuries, as well as the relationship between radial head fractures and osteoporosis, were discussed in part II. Part III focused on the incidence and clinical relevance of osseous, cartigilanous, and ligamentous, associated injuries in elbows with a radial head fracture. Injury to the medial collateral ligament (MCL) was discussed in a broader spectrum and in more detail. In part IV a systematic review was performed on the treatment of stable Mason type II fractures without associated fractures or elbow dislocation. This part also described the short-term results of the cemented and press-fit radial head prostheses in patients with post-traumatic disorders of the elbow. The inter- and intra-observer agreement of the Mason-Hotchkiss classification was also evaluated.

Part I: General introduction and current issues The radial head is one of the three bones of the elbow joint. Together with the proximal ulna and distal humerus, it forms the ‘articulatio cubiti’ or elbow joint. The radial head is an important bony stabilizer of the elbow joint.4 Fracture of the radial head occurs as a result of a fall on the outstretched arm with the elbow in slight flexion and pronation.5 Radial head fractures can be classified according to the Mason classification6, or one of its modifications.7-9 Clinically relevant associated injuries occur in up to one third of all elbows with a radial head fracture10 and are of great importance in treating patients with (complex) elbow trauma.1 On physical examination the radial head is painful on palpation and a heamarthrosis is seen. Elbow range of motion, especially pro- and supination, is decreased because of pain. Ligamentous injury can be suspected in case of pain on palpation and/or ecchymosis of the medial and/or lateral aspects of the elbow. Stability and neurovascular status should be examined and one should look for associated injuries. The diagnosis can be made with lateral and anteroposterior (AP) radiographs of the elbow. To determine the number of fragments and/or dislocation, a CT scan of the elbow can be performed. Minimally displaced (Mason type I) radial head fractures can be treated non-operatively with early mobilization and results are good in 85-95% of the patients.11, 12 Treatment of displaced fractures (Mason type II) is still subject of debate: non-operative treatment or ORIF.13 Comminuted fractures of the radial head are treated surgically, either with ORIF Discussion and summary 133 or radial head arthroplasty.14 ORIF of comminuted fractures consisti ng of >3 fragments is associated with high rates of non-union or failure.15 Radial head excision can be performed in isolated, un-reconstructable Mason type III fractures and sati sfactory results have been described16, 17, but are related to complicati ons as instability and wrist pain, especially in pati ents with a high demand of their elbow functi on.1

Part II: Epidemiology of radial head fractures and the relati on to osteoporosis Few reports on the epidemiology of radial head fractures and their associated osseous injuries are currently available and litt le is known about the incidence of radial head fractures and their associated injuries in the European populati on. Recent literature shows an increased mean age of female pati ents with radial head fractures compared with male pati ents with radial head fractures.10, 18 However, data on epidemiology of radial head fractures and specifi cally in relati on to age distributi on and male-female rati os of radial head fracture are scarce. In chapter 3 we described the epidemiology of radial head fractures in the Dutch populati on, especially the age distributi on and male-female rati o, and their associated osseous injuries in the Dutch populati on. We retrospecti vely reviewed all 328 radial head fractures that were diagnosed in 322 pati ents over a period of 3 years. The incidence was 2.8 per 10,000 inhabitants per year. The male-female rati o was 2:3. The mean age was 48.0 years (range: 14-88 years, SD, 14.8). The mean age of female pati ents (52.8 years) was signifi cantly higher than that of male pati ents (40.5 years) (P < 0.001). As the age increased above 50 years, the number of female pati ents became signifi cantly higher than the number of male pati ents (P < 0.001). These epidemiologic fi ndings suggested a possible link between radial head fractures and osteoporosis. Associated osseous injuries, such as scaphoid or olecranon fractures, occurred in 40 pati ents (12.4%). The treati ng physician should be aware of associated injuries when treati ng pati ents with radial head fractures. In chapter 4 we further investi gated the relati onship between radial head fractures and osteoporosis in females ≥50 years of age with a retrospecti ve case-control study. The hypothesis was that females ≥50 years with a radial head fracture have an increased risk of osteoporosis, compared to female pati ents of the same age without a radial head fracture. Peripheral BMD measurement of pati ents and controls was performed at the calcaneus using the DXL Calscan. The 35 women ≥50 years of age with a radial head fracture (cases) had an increased risk of osteoporosis compared to the 57 for age matched female controls, with an OR of 3.4, with a P-value of 0.027. Although pati ent numbers in this study were limited, these results are supported by the age distributi on and male-female rati o of radial 11 head fractures (as described in the previous chapter)10, 19 and osteoporoti c changes in the micro-architecture of the radial head in human cadavers.20 As radial head fractures occur on average earlier in life compared to other known osteoporoti c fractures, for example distal radius or hip fractures21, recogniti on of radial head fractures as potenti al osteopo- 134 Chapter 11

rotic fractures can be of great potential importance: offering these patients screening and treatment of osteoporosis might prevent other future osteoporotic fractures. However, prospective studies with larger patient numbers are in need to determine the exact relative risk of osteoporosis in elderly patients with a radial head fracture.

Part III: Associated injuries of radial head fractures Over the past years an increasing awareness of the importance of associated injuries in the treatment of radial head fractures has been reported.8, 22 In a retrospective study of 333 patients with a radial head fracture by van Riet et al., clinically relevant associated fractures and/or soft-tissue injuries were diagnosed in 39% of the patients.10 Recent studies using magnetic resonance imaging (MRI) show a high incidence (92%) of associated injuries in patients with a Mason type III radial head fracture.23 However, the clinical relevance of concomitant injuries found with MRI was unclear. Early diagnosis of these injuries using MRI, combined with knowledge of the clinical relevance of these injuries might provide greater understanding of injuries of the patient with a radial head fracture, and optimise (surgical) treatment and provide the patient with a better estimate of their prognosis. To assess the incidence and clinical relevance of these injuries, we performed a MRI scan of the elbow in 46 patients with a radial head fracture in chapter 5. 17 elbows had a Mason type I fracture, 23 had a Mason type II fracture, and 6 elbows had a Mason type III fracture. Associated injuries were found in 35 elbows. 28 elbows had a lateral collateral ligament lesion, 18 had injury of the capitellum. One elbow had a coronoid fracture and 1 elbow had medial collateral ligament injury. 40 of these patients with 42 radial head fractures were evaluated after a mean period of 13.3 months in chapter 6. The mean Mayo Elbow Performance Scale was 97.5 (range: 80-100), with no significant difference between patients with and without associated injuries (p = 0.8). 3 elbows had clinical MCL or LCL laxity, of which 2 elbows had no ligamentous injuries diagnosed with MRI. 1 elbow with a loose osteochondral fragment showed infrequent elbow locking. So we can conclude that most injuries found with MRI in patients with radial head fractures are not symptomatic or of clinical importance in short term follow-up. This could explain the difference in high incidence of concomitant injuries found with MRI23, 24 and the lower incidence of clinically relevant associated injuries on physical examination found by van Riet et al.10 However, the population in our studies was too diverse and too small to draw firm conclusions on the clinical relevance of associated injuries in subgroups. Follow-up was too short to assess the precise clinical consequences of the osteochondral lesions, as these patients might be more prone to develop osteoarthritis in later life compared to those without osteochondral lesions. In chapter 7 we described the MCL (or UCL) in a broader spectrum, as it can occur as a result of a posterolateral dislocation of the elbow (with a radial head fracture), but also as Discussion and summary 135 the result of chronic att enuati on in (throwing) athletes and as an isolated injury. Although MCL injuries are uncommon in daily clinical practi ce, it is important to recognize this injury in pati ents with (post-traumati c) medial elbow complaints.25-27 As this injury is relati vely unknown, we provided an overview of current literature on MCL injury in this chapter. It is important to recognize this injury in pati ents with (past traumati c) medial elbow pain. Exact numbers or incidence of this injury in athletes or in the general populati on are unknown. The preferred imaging technique for detecti on of MCL injuries of the elbow is MRI with arthrography.28, 29 Treatment of MCL of the elbow injuries is based on the pati ents’ athleti c demands and the degree of MCL injury. Initi al non-operati ve treatment consists of rest, anti -infl ammatory measures and physical therapy, with sati sfactory results in 42% of the pati ents.30 If non-operati ve treatment fails, surgical MCL reconstructi on can be performed, with success rates of 63-95%, depending on the technique used.31-33 The current overall quality of evidence on this subject is very low and prospecti ve studies to determine preferable diagnosti c technique, best graft fi xati on techniques and long term results of conservati ve and surgical treatment are in demand. In chapter 8 it was our goal to establish the inter- and intra observer agreement of the Mason-Hotchkiss classifi cati on and the infl uence of clinical experience on agreement, as it is of importance in daily decision making when treati ng pati ents with a radial head fracture. The inter-observer agreement was substanti al and the intra-observer agreement ranged from fair to substanti al. We observed that experienced surgeons scored a higher (almost perfect) inter-observer agreement, compared to the lower end of substanti al agreement between residents. However, this diff erence was not stati sti cally signifi cant. The κ-value for intra-observer agreement for surgical or conservati ve treatment was 0.69, and inter-observer agreement ranged between 0.38 to 0.57.

Part IV: Classifi cati on and treatment In chapter 9 we performed a systemati c review on the treatment of Mason type II radial head fractures, without associated fractures or elbow dislocati on to inform the current debate on surgical or non-operati ve treatment. Of the 149 relevant studies found, only 9 retrospecti ve case series met the inclusion criteria, describing 224 pati ents. Non-operati ve treatment was successful in average of 80% (114 of 142) pati ents (range 43 to 96% in various studies). Open reducti on and internal fi xati on (ORIF) was successful in 93% (76 of 82) pati ents (range 81 to 100%). Although surgical treatment showed signifi cant better outcome (P = 0.01), strong conclusions cannot be drawn from the currently available literature as the level of evidence is weak and the reports on surgical treatment were 11 usually meant to describe or promote a new surgical technique. Retrospecti ve studies not included in this review reported good long term results with non-operati ve treatment of Mason type II fractures aft er a mean follow-up of 19 years.34, 35 Prospecti ve, randomized clinical trials are needed to determine which treatment provides the best results for these 136 Chapter 11

stable Mason type II fractures. If an adequate treatment strategy based on prospective studies can be developed, a new treatment-based classification system for radial head fractures could be developed. Un-reconstructable, multi-fragment radial head fractures can be treated with radial head arthroplasty.14 Various implants are currently available and can be divided in two types: monoblock and bipolar implants. In chapter 10 we discussed the short-term results of the cemented and press-fit bipolar Judet implant, in a retrospective review of 33 patients with post-traumatic injuries of the elbow. 19 patients scored excellent, 10 scored good, 1 fair and 3 poor on the Mayo Elbow Performance Index, with a median of 100 (range: 55-100). The median Elbow Function Assessment score was 94 (SD: range: 60-100). The median functional range of motion was 130° (range: 80°-145°). Median supination and pronation were 70°. These results are similar to those reported in the literature.36-38 However, a good comparison is difficult, as the included patient characteristics, like type of injury, associated injuries and revision surgery highly vary between studies. Although short-term results of both implant types were similar, 11 of the 16 elbows (69%) with a press-fit implant showed osteolysis of the proximal radius of which the clinical relevance is unknown. A possible cause of this osteolysis can be polyethylene wear (PE). Histological evidence of PE wear in bipolar implants was reported by O’Driscoll and Herald.39 However, it is unlikely as the mean follow-up period of these patients (28 months) is too short to cause significant wear debris and it was not seen in the elbows with a cemented implant, of which the mean follow-up period was significantly longer (36 months). It is likely that stress shielding is the most important factor for the osteolysis of the proximal radius in the press-fit group: The short, rigid stem of the press-fit design is more prone to stress shielding, compared to the long, thinner, more flexible stem of the cemented implant.40 The clinical relevance of the proximal osteolysis is unknown, so long-term follow-up results are indicated. In conclusion, the functional results of the cemented and press-fit bipolar radial head prosthesis are generally good, but the clinical relevance of the proximal osteolysis associated with the press-fit implant has to be investigated. Discussion and summary 137

REFEREnCE LIST

(1) van Riet RP, van Glabbeek F, Morrey BF. Radial Head Fracture: General Considerati ons, Conservati ve Treatment and Open Reducti on and Internal Fixati on. In: Morrey B, Sanchez-Sotelo J, editors. The Elbow and its Disorders. 4 ed. Philadelphia: Saunders; 2009. p. 359-81. (2) Aegina P. Fractures and Dislocati on. London: New Sydenham Society; 1846. (3) Jones SG. Fractures of the head and neck of the radius - seperati on of the upper radial epiphysis. New England Journal of Medicine 1935;212: 914-7. (4) O’Driscoll SW, Jupiter JB, King GJ, Hotchkiss RN, Morrey BF. The unstable elbow. Instr Course Lect 2001;50: 89-102. (5) Amis A, Miller J. Mechanisms of elbow fractures: an investi gati on using impact tests in vitro. Injury 1995;26(3): 163-8. (6) Mason ML. Some observati ons on fractures of the head of the radius with a review of one hundred cases. Br J Surg 1954;42: 123-32. (7) Hotchkiss RN. Displaced fractures of the radial head: internal fi xati on or excision? J Am Acad orthop Surg 1997;5: 1-10. (8) van Riet RP, Morrey BF. Documentati on of associated injuries occurring with radial head fracture. Clin Orthop Relat Res 2008 Jan;466(1): 130-4. (9) Broberg MA, Morrey BF. Results of treatment of fracture-dislocati ons of the elbow. Clin Orthop Relat Res 1987 Mar;(216): 109-19. (10) van Riet RP, Morrey BF, O’Driscoll SW, van Glabbeek F. Associated injuries complicati ng radial head fractures: a demographic study. Clin Orthop Relat Res 2005;441: 351-5. (11) Herbertsson P, Josefsson PO, Hasserius R, Karlsson C, Besjakov J, Karlsson MK. Displaced Mason type I fractures of the radial head and neck in adults: a fi ft een- to thirty-three-year follow-up study. J Shoulder Elbow Surg 2005 Jan;14(1): 73-7. (12) Rosenblatt Y, Athwal GS, Faber KJ. Current recommendati ons for the treatment of radial head fractures. Orthop Clin North Am 2008 Apr;39(2): 173-85, vi. (13) Struijs PA, Smit G, Steller EP. Radial head fractures: eff ecti veness of conservati ve treatment versus surgical interventi on. A systemati c review. Arch Orthop Trauma Surg 2007 Feb; 127(2): 125-30. (14) Ring D. Displaced, unstable fractures of the radial head: fi xati on vs. replacement--what is the evidence? Injury 2008 Dec;39(12): 1329-37. (15) Ring D. Open reducti on and internal fi xati on of fractures of the radial head. Hand Clin 2004 Nov; 20(4):415-27, vi. (16) Karlsson MK, Herbertsson P, Nordqvist A, Besjakov J, Josefsson PO, Hasserius R. Comminuted fractures of the radial head. Acta Orthop 2010 Apr;81(2): 226-9. (17) Antuna SA, Sanchez-Marquez JM, Barco R. Long-term results of radial head resecti on following isolated radial head fractures in pati ents younger than forty years old. J Bone Joint Surg Am 2010 Mar;92(3): 558-66. (18) Gebauer M, Rucker AH, Barvencik F, Rueger JM. [Therapy for radial head fractures]. Unfallchirurg 2005 Aug;108(8): 657-67. (19) Kaas L, van Riet RP, Vroemen J, Eygendaal D. The epidemiology of radial head fractures. J Shoulder Elbow Surg 2010 Jun 1;19(4): 520-3. 11 (20) Gebauer M, Barvencik F, Mumme M, Beil FT, Vett orazzi E, Rueger JM, et al. Microarchitecture of the Radial Head and Its Changes in Aging. Calcif Tissue Int 2009 Nov 13. 138 Chapter 11

(21) Mallmin H, Ljunghall S, Persson I, Naessen T, Krusemo UB, Bergstrom R. Fracture of the distal forearm as a forecaster of subsequent hip fracture: a population-based cohort study with 24 years of follow-up. Calcif Tissue Int 1993 Apr; 52(4): 269-72. (22) Davidson PA, Moseley JB, Jr., Tullos HS. Radial head fracture. A potentially complex injury. Clin Orthop Relat Res 1993 Dec; (297): 224-30. (23) Itamura J, Roidis N, Mirzayan R, Vaishnav S, Learch T, Shean C. Radial head fractures: MRI evaluation of associated injuries. J Shoulder Elbow Surg 2005 Jul; 14(4): 421-4. (24) Kaas L, Turkenburg JL, van Riet RP, Vroemen J, Eygendaal D. Magnetic resonance imaging findings in 46 elbows with a radial head fracture. Acta Orthopaedica 2010; 81(3): 373-6. (25) Han KJ, Kim YK, Lim SK, Park JY, Oh KS. The effect of physical characteristics and field position on the shoulder and elbow injuries of 490 baseball players: confirmation of diagnosis by magnetic resonance imaging. Clin J Sport Med 2009 Jul; 19(4): 271-6. (26) Eygendaal D, Verdegaal SH, Obermann WR, van Vugt AB, Poll RG, Rozing PM. Posterolateral dislocation of the elbow joint. Relationship to medial instability. J Bone Joint Surg Am 2000 Apr; 82(4): 555-60. (27) Eygendaal D, Heijboer MP, Obermann WR, Rozing PM. Medial instability of the elbow: findings on valgus load radiography and MRI in 16 athletes. Acta Orthop Scand 2000 Oct; 71(5): 480-3. (28) Timmerman LA, Schwartz ML, Andrews JR. Preoperative evaluation of the ulnar collateral ligament by magnetic resonance imaging and computed tomography arthrography. Evaluation in 25 baseball players with surgical confirmation. Am J Sports Med 1994 Jan; 22(1): 26-31. (29) Schwartz ML, al-Zahrani S, Morwessel RM, Andrews JR. Ulnar collateral ligament injury in the throwing athlete: evaluation with saline-enhanced MR arthrography. Radiology 1995 Oct; 197(1): 297-9. (30) Rettig AC, Sherrill C, Snead DS, Mendler JC, Mieling P. Nonoperative treatment of ulnar collateral ligament injuries in throwing athletes. Am J Sports Med 2001 Jan; 29(1): 15-7. (31) Conway JE, Jobe FW, Glousman RE, Pink M. Medial instability of the elbow in throwing athletes. Treatment by repair or reconstruction of the ulnar collateral ligament. J Bone Joint Surg Am 1992 Jan; 74(1): 67-83. (32) Savoie FH, III, Nunley PD, Field LD. Arthroscopic management of the arthritic elbow: indications, technique, and results. J Shoulder Elbow Surg 1999 May; 8(3): 214-9. (33) Bowers AL, Dines JS, Dines DM, Altchek DW. Elbow medial ulnar collateral ligament reconstruction: clinical relevance and the docking technique. J Shoulder Elbow Surg 2010 Mar; 19(2 Suppl): 110-7. (34) Akesson T, Herbertsson P, Josefsson PO, Hasserius R, Besjakov J, Karlsson MK. Primary nonoperative treatment of moderately displaced two-part fractures of the radial head. J Bone Joint Surg Am 2006 Sep; 88(9): 1909-14. (35) Herbertsson P, Josefsson PO, Hasserius R, Karlsson C, Besjakov J, Karlsson M. Uncomplicated Mason type-II and III fractures of the radial head and neck in adults. A long-term follow-up study. J Bone Joint Surg Am 2004 Mar; 86-A(3): 569-74. (36) Dotzis A, Cochu G, Mabit C, Charissoux JL, Arnaud JP. Comminuted fractures of the radial head treated by the Judet floating radial head prosthesis. J Bone Joint Surg Br 2006 Jun; 88(6): 760-4. (37) Judet T, Garreau de LC, Piriou P, Charnley G. A floating prosthesis for radial-head fractures. J Bone Joint Surg Br 1996 Mar; 78(2): 244-9. (38) Popovic N, Lemaire R, Georis P, Gillet P. Midterm results with a bipolar radial head prosthesis: radiographic evidence of loosening at the bone-cement interface. J Bone Joint Surg Am 2007 Nov; 89(11): 2469-76. Discussion and summary 139

(39) O’Driscoll SW, Herald J. Symptomati c failure of snap-on bipolar radial head prosthesis. J Shoulder Elbow Surg 2009 Sep;18(5): e7-11. (40) Huiskes R, Weinans H, Van RB. The relati onship between stress shielding and bone resorpti on around total hip stems and the eff ects of fl exible materials. Clin Orthop Relat Res 1992 Jan; (274): 124-34.

Chapter 12 Conclusions and recommendations for future research

L. Kaas 142 Chapter 12

COnCLuSIOnS

Based on the results of the studies presented in chapter 3 to 10 of this thesis, several conclusions can be drawn: Chapter 3: First of all, we conclude that radial head fractures are common, with an estimated incidence of 2.8 per 10.000 inhabitants per year. Male-female ratio was 2:3, with females being significantly older compared to males, suggesting a possible link to osteoporosis. They are accompanied by associated osseous injuries in 12.4% of the cases. The treating physician should be aware of these injuries when treating patients with radial head fractures. Chapter 4: Radial head fractures in female patients ≥50 years are identified as potential osteoporotic fractures. These patients had an increased risk of osteoporosis, withan odds ratio of 3.4. This could explain the typical age distribution of patients with a radial head fracture. Identifying radial head fractures in these patients as potential osteoporotic fractures and offering a BMD measurement improves the early diagnosis of osteoporosis. Chapter 5 and 6: Associated injuries are found in 35 of 46 elbows (76%) with a radial head fracture with MRI of the elbow. (Partial) rupture of the LCL and injuries to the capitellum were most frequently diagnosed. The clinical relevance of the injuries found with MRI in elbows with radial head fractures is investigated and we conclude that only 4% of these injuries are symptomatic or of clinical importance after one year. Chapter 7: UCL insufficiency of the elbow has been mainly reported in athlete’s and in patients with posttraumatic conditions of the elbow (e.g. postero-lateral elbow dislocation) and can be diagnosed with MRI arthrography. Treatment of UCL of the elbow injuries is based on the patients (athletic) demands and the degree of UCL injury and primarily consists of a non-operative treatment. Only symptomatic UCL insufficiency is an indication for reconstruction. The optimal surgical technique is still subject of discussion. Chapter 8: Few studies on inter- and intra-observer reliability of the Mason classification or its modifications are available and only one on the Mason-Hotchkiss classification. The inter-observer agreement was substantial and the intra-observer agreement ranged from fair to substantial with 4 different observers with different levels of experience. More clinical experience did not significantly improve agreement. Chapter 9: Few studies with a low level of evidence address the treatment of isolated, displaced, partial articular radial head fractures are available. In these studies, non-operative treatment was successful in an average of 80% of the patients. ORIF was successful in an average 93% of the patients. These data must be interpreted in light of the fact that many of the case series of ORIF were written to introduce or promote operative techniques. Chapter 10: The short-term functional results of the cemented and press-fit Judet bipolar radial head prosthesis are good or excellent in 88% patients with post-traumatic disorders of the radial head. However, osteolysis of the proximal radius was found in 69% Discussion and summary 143 of the pati ents with a press-fi t design, without any relati on to the clinical outcome. The exact cause and whether this osteolysis is progressive remains unknown.

RECOMMEnDATIOnS FOR FuTuRE RESEARCH

Although the knowledge on radial head fractures and its associated injuries has signifi cantly increased over the past decade, many aspects of radial head fractures remain subject of discussion. In this thesis, we linked radial head fractures in women ≥50 years of age to osteoporosis, to explain the typical age and sex distributi on of pati ents with a radial head fracture. In chapter 4 we support this theory in a retrospecti ve case-control study using a peripheral bone densometry. Although we found an increased risk of osteoporosis in females with a radial head fracture, prospecti ve case-control studies with suffi cient pati ent numbers are indicated to improve the level of evidence. The bone densometry should be performed using a standard DEXA-scan, sti ll regarded as the golden standard. As we already concluded in chapter 9, there is a strong need for randomized clinical trials on the acute treatment of Mason type II (non-operati ve vs. ORIF). The pati ent populati on and baseline characteristi cs, such as radial head fracture type, associated osseous injuries, dominance and age should be well described. A follow-up period of at least 12 months is desirable. Data like range of moti on (especially pro- and supinati on), re-surgery, pain and complicati ons should also be assessed. Clinician based and pati ent reported outcome measures, such as the Broberg and Morrey score, Mayo Elbow Performance Index and DASH-score, will make the results of treatment more comparable. On the other hand, none of these scores are validated for elbows with a radial head fracture. Although most short-term results of radial head implants in pati ents with un-reconstructable radial head fractures are good, long term results are scarce. In chapter 10 we discussed results of cemented and press-fi t bipolar radial head prosthesis with a minimal follow-up of two years and observed osteolysis of the proximal radius in 69% of the elbows with a press-fi t implant. The exact cause and clinical implicati on of this osteolysis are unknown. Long-term follow-up of pati ents with a radial head prosthesis, but also biomechanical research on factors such as stress shielding of this implant are necessary.

Chapter 12 De radiuskopfractuur: Een potentieel complex letsel

L. Kaas

Nederlandstalige samenvatti ng 147

nEDERLAnDSTALIGE DISCuSSIE En SAMEnVATTInG

Eén derde van de fracturen van de elleboog is een radiuskopfractuur, en deze komt daarmee dus vaak voor.1 De radiuskopfractuur werd waarschijnlijk voor het eerst beschreven door Paul van Aegina (625-690 na Christus).2 In 1935 stelde Jones: “De radiuskopfractuur is een ernsti g letsel. Hoewel de prognose voor een goed herstel van een functi onele elleboog over het algemeen goed is, wordt het zelden een normale elleboog.” Hoewel de afgelopen jaren de wetenschappelijke belangstelling en kennis over radiuskopfracturen en zijn begeleidende letsels is toegenomen, zijn er nog vele aspecten van deze veel voorko- mende fractuur onduidelijk. Dit proefschrift bestaat uit 4 delen, en in ieder deel wordt een aspect van de radiuskopfractuur belicht. Een algemene introducti e met betrekking tot de anatomie, eti ologie, diagnose en behandeling wordt gegeven in deel I. De epidemiologie van radiuskopfracturen en zijn begeleidende letsels wordt beschreven in deel II. Ook de relati e van radiuskopfracturen met osteoporose wordt in dit deel onderzocht. Het derde deel van dit proefschrift beschrijft de incidenti e en klinische relevanti e van begeleidende letsels (ligamentair, carti liganeus of ossaal) bij ellebogen met een radiuskopfractuur. Daarnaast wordt het letsel van de mediale collaterale band verder uitgediept. In deel IV wordt met een systemati sche review van de literatuur conservati eve en chirurgische behandeling van stabiele, geïsoleerde Mason type II radiuskopfracturen vergeleken. In dit deel worden ook de resultaten van gecementeerde en ongecementeerde radiuskopprothesen beschreven bij pati ënten met post-traumati sche afwijkingen van de elleboog na een radiuskopfractuur. Tevens wordt de intra- en inter-observer overeenkomst van de Mason-Hotchkiss classifi cati e voor radiuskopfracturen onderzocht.

Deel I: Algemene introducti e en stand van zaken Het radiuskopje vormt samen met de proximale ulna en de distale humerus het elleboogs- gewricht, ofwel de “arti culati o cubiti ”, en is één van de benige stabilatoren van de elleboog.3 Een fractuur van het radiuskopje ontstaat door een val op de uitgestrekte arm, met de elleboog in lichte fl exie en pronati e.4 Ze kunnen worden ingedeeld volgens de Mason classifi cati5 e , of een van zijn modifi cati es die de afgelopen decennia zijn geïntroduceerd.6-8 Bij één derde van de radiuskopfracturen komen klinisch relevante begeleidende letsels voor.9 Deze zijn van groot belang voor een adequate behandeling van pati ënten met een complex trauma van de elleboog.1 Bij lichamelijk onderzoek is er hydrops van de elleboog, een drukpijnlijk radiuskopje en functi o laesa. Daarnaast moet er gelet worden op begeleidende letsels en stabiliteit van de elleboog. Diagnosti ek bestaat uit röntgenfoto’s van de elleboog. Bij twijfel over de dislocati e of het aantal fractuurfragmenten kan er een CT ver- 12 richt worden. Weinig gedisloceerde radiuskopfracturen (Mason type I) kunnen functi oneel 148

worden behandeld, met goede resultaten bij 85 tot 95% van de patiënten.10, 11 De optimale behandeling van gedisloceerde radiuskopfracturen (Mason type II) staat nog ter discussie: conservatief of open reductie en interne fixatie (ORIF).12 Comminutieve radiuskopfracturen (Mason type III) worden chirurgisch behandeld met ORIF of een radiuskopporthese.13 ORIF van radiuskopfracturen die bestaan uit meer dan drie verschillende fragmenten wordt echter geassocieerd met een verhoogd risico op non-union.14 Excisie van het radiuskopje kan worden verricht in het (zeldzame) geval van geïsoleerde comminutieve, radiuskopfracturen. Er worden goede resultaten beschreven van deze behandeling15, 16, maar dit gaat gepaard met een hoog risico op instabiliteit van de elleboog en polsklachten ten gevolge van proximalisatie van de radius.1

Deel II: Epidemiologie van radiuskopfracturen en de relatie met osteoporose Er zijn slechts enkele studies beschikbaar over de epidemiologie van radiuskopfracturen en zijn begeleidende letsels, en er is weinig bekend over deze letsels in de Europese populatie. Recente studies laten zien dat vrouwelijke patiënten met een radiuskopfractuur gemiddeld ouder zijn dan mannelijke patiënten met dit letsel.9, 17 Gegevens over de geslachts- en leeftijdsdistributie van zijn schaars. Het doel van hoofdstuk 3 is dan ook het beschrijven van de epidemiologie van radiuskopfracturen en begeleidende fracturen in de Nederlandse populatie, met specifieke aandacht voor de geslachts- en leeftijdsdistributie. Hiervoor hebben we retrospectief de gegevens bekeken van 322 patiënten met 328 radiuskopfracturen in de periode van 2006 tot 2009. De incidentie was 2.8 per 10.000 inwoners per jaar met een man-vrouw ratio van 2:3. De gemiddelde leeftijd bedroeg 48.0 jaar, met een standaard deviatie (SD) van 14.8 jaar. Vrouwen met een radiuskopfractuur waren gemiddeld significant ouder (52.8 jaar) vergeleken met mannen (40.5 jaar) (P < 0,001). Bij patiënten ouder dan 50 jaar is het aantal vrouwen significant hoger dan het aantal mannen (P < 0,001). Begeleidende ossale letsels van de ipsilaterale bovenste extremiteit, zoals scaphoïd- en olecranonfracturen, kwamen voor bij 40 patiënten voor (12.4%). Deze bevindingen suggereren een mogelijk verband tussen radiuskopfracturen en osteoporose. Daarnaast moet de behandelaar rekening houden met (en actief zoeken naar) de begeleidende fracturen die kunnen voorkomen bij een patiënt met een radiuskopfractuur. In hoofdstuk 4 wordt de relatie tussen radiuskopfracturen en osteoporose verder onderzocht bij vrouwen ≥50 jaar met een retrospectieve case-control studie. Hierbij was de hypothese dat bij vrouwen ≥50 jaar mét een radiuskopfractuur een verhoogde incidentie is van osteoporose, vergeleken met vrouwen ≥50 jaar zónder een fractuur. De patiënten en controles ondergingen hiervoor een botdichtheidmeting van de calcaneus met de DXL Calscan. De 35 vrouwen met een radiuskopfractuur hadden een verhoogd risico op osteoporose, in vergelijking met de 57 voor leeftijd gepaarde controles, met een odds ratio (OR) van 3.4 (P = 0.027). Hoewel het aantal onderzochte patiënten beperkt is, worden deze resultaten ondersteund door de voor osteoporose kenmerkende epidemio- Nederlandstalige samenvatti ng 149 logie (zoals beschreven in hoofdstuk 3)9, 18 en bij osteoporose passende veranderingen in de microarchitectuur van het bot van radiuskopjes bij menselijke kadavers.19 Aangezien radiuskopfracturen gemiddeld op vroegere leeft ijd voorkomen (in vergelijking met andere bekende osteoporoti sche fracturen, zoals distale radius, wervel- en heupfracturen20) kan herkenning van radiuskopfracturen als potenti ële osteoporoti sche fracturen van groot voordeel zijn: screening op osteoporose bij deze pati ënten zou toekomsti ge fracturen kunnen voorkomen. Er zijn echter nog prospecti eve studies nog met grotere pati ëntaantallen om het exacte relati eve risico op osteoporose te bepalen.

Deel III: begeleidende letsels bij radiuskopfracturen In de afgelopen jaren wordt het belang van begeleidende letsels in een adequate behandeling van radiuskopfracturen steeds meer onderkend.8, 21 In een retrospecti eve studie van 33 pati ënten met een radiuskopfractuur werd er bij 39% van de pati ënten klinisch relevant begeleidend letsels gevonden.9 Een studie waarbij door Van Riet et al. ellebogen met een Mason type III radiuskopfractuur worden gescand middels een MRI laten begeleidende letsels zien bij 92% van pati ënten.22 De klinische relevanti e van deze letsels die worden gevonden middels MRI is echter nog onbekend. Een snelle diagnose van deze letsels middels MRI na het trauma, gecombineerd met een beter inzicht in de klinische relevanti e hiervan, kan tot een beter inzicht leiden in de radiuskopfractuur en zijn begeleidende letsels, en zou daarmee de (chirurgische) behandeling kunnen opti maliseren. Om de incidenti e en klinische relevanti e van begeleidende letsels van alle typen radiuskopfracturen bij MRI te onderzoeken, hebben we in hoofdstuk 5 een MRI van 46 ellebogen verricht bij 45 pati ënten met een radiuskopfractuur. Zeventi en ellebogen hadden een Mason type I fractuur, 23 een Mason type II fractuur en 6 een type III fractuur. Begeleidende letsels werden gevonden in 35 ellebogen (76%). 28 Ellebogen hadden letsel van het laterale collaterale ligament (LCL) en bij 18 ellebogen werd letsel van het capitellum gevonden. Een fractuur van het processus coronoïdeus en een letsel van de mediale collaterale band (MCL) werden ieder in één elleboog gevonden. De klinische relevanti e van deze letsels werd onderzocht in hoofdstuk 6. Veerti g van de in het vorige hoofdstuk gescande pati ënten met 42 radiuskopfracturen werden gemiddeld 13.3 maanden na het trauma opnieuw onderzocht. De gemiddelde score op de Mayo Elbow Performance Score (MEPS) was 97.5 (range: 80-100). Er was geen signifi cant verschil tussen pati ënten met en zonder fractuur (P = 0.8). Drie ellebogen toonden klinisch laxiteit van het LCL of MCL, waarvan er bij 2 géén ligamentair letsel te zien was bij de MRI scan. Eén pati ënt met een los osteochondraal letsel had af en toe slotklachten. We kunnen dus concluderen dat de meeste letsels die worden gevonden met MRI niet klinisch relevant zijn of symptomati sch worden bij follow-up op korte termijn. Dit kan het verschil verklaren tussen de incidenti e van begeleidende letsels die worden gevonden met MRI22, 23 en de lagere incidenti e van 12 klinisch relevante letsels gevonden door Van Riet et al. In 2005.9 Harde conclusies kunnen 150

echter op basis van deze twee studies niet worden getrokken, aangezien onze studiepopu- latie klein en divers is. Ook was de follow-up relatief kort: osteochondrale letsels kunnen bijvoorbeeld pas jaren later symptomatisch worden. In hoofdstuk 7 wordt verder ingegaan op letsel van het MCL. Een dergelijk letsel kan niet alleen ontstaan bij een radiuskopfractuur, maar kan ook het gevolg zijn van een postero- laterale dislocatie van de elleboog (evt. met radiuskopfractuur), of van chronische over- belasting bij werpsporters, of als geïsoleerd traumatisch letsel. Hoewel MCL letsels in de dagelijkse orthopedische praktijk niet vaak voor zullen komen en daarmee vrij onbekend zijn, is het belangrijk om dit letsel te herkennen bij patiënten met (post-traumatische) klachten aan de mediale zijde van de elleboog.24-26 Het doel van dit hoofdstuk is een over- zicht te geven van de beschikbare literatuur op dit gebied. De incidentie van MCL letsel in de algemene populatie of bij sporters is niet bekend. MCL letsels kunnen het meest accuraat gediagnosticeerd worden met MRI arthrografie.27, 28 De behandeling is afhankelijk van de (atletische) functie-eisen van de elleboog en de ernst van het letsel en bestaat op de eerste plaats uit rust, NSAID’s en fysiotherapie. Dit leidt bij 42% van de patiënten in een goed resultaat.29 Als conservatieve behandeling faalt kan er gekozen worden voor chirurgische reconstructie van het MCL. Afhankelijk van de gebruikte techniek, is het resultaat goed bij 63-95% van de patiënten.30-32 De studies op dit gebied bestaan echter vooralsnog uit retrospectieve case series met een relatief korte follow-up. (Prospectieve) studies met een adequate follow-up zijn dan ook nodig om de beste behandelstrategie te bepalen. In hoofdstuk 8 is het doel om de inter- en intra-observer overeenkomst van de Mason- Hotckiss classificatie vast te stellen en of klinische ervaring invloed heeft op de mate van overeenkomst. Dit is van belang bij het maken van behandelbeslissingen bij patiënten met een radiuskopfractuur. In het onderzoek is de inter-observer overeenkomst substantieel en de intra-observer overeenkomst is redelijk tot substantieel. Ervaren chirurgen scoren een hogere (bijna perfecte) inter-observer overeenkomst, vergeleken met substantiële overeenkomst tussen arts-assistenten. Dit verschil is echter niet statistisch significant. De κ-waarde voor intra-observer overeenkomst voor chirurgische of conservatieve behandeling is 0.69, en voor inter-observer overeenkomst tussen 0.38 en 0.57.

Deel IV: Classificatie en behandeling In hoofdstuk 9 wordt een systematische review verricht naar de behandeling van geïso- leerde Mason type II radiuskopfracturen, met als doel te kijken of conservatieve, dan wel operatieve behandeling een beter resultaat geeft, en om inzicht te geven in de kwaliteit van het wetenschappelijke bewijs. Er werden na een zoekactie 149 relevante studies gevonden, waarvan slechts 9 retrospectieve case series voldeden aan de inclusiecriteria, die in totaal 224 patiënten beschreven. Conservatieve behandeling was succesvol bij 114 van de 142 van de patiënten (80%), met een range van 43 tot 96%. Open reductie en interne fixatie (ORIF) was succesvol bij 76 van de 82 patiënten (93%), met een range van Nederlandstalige samenvatti ng 151

81 tot 100%. Hoewel chirurgische behandeling dus signifi cant beter is (P = 0.01), dient men voorzichti g te zijn met het vertalen van deze resultaten naar de dagelijkse prakti jk. De methodologische kwaliteit van de studies is zwak met een korte follow-up, en de studies over de operati eve behandeling promoten voornamelijk een nieuwe operati eve techniek of materiaal. Daarnaast zijn er studies die niet voldeden aan de inclusiecriteria voor deze review, die wel goede resultaten laten zien bij conservati ef behandelde type II fracturen met een follow-up van gemiddeld 19 jaar.33, 34 Prospecti eve, gerandomiseerde klinische trials zijn nodig om te bepalen welke behandelopti e de beste resultaten geeft bij deze geïsoleerde, stabiele Mason type II fracturen. Niet reconstrueerbare, comminuti eve radiuskopfracturen kunnen behandeld worden met een radiuskopprothese.13 Er zijn diverse implantaten beschikbaar, die kunnen worden verdeeld in twee types: monoblock en bipolaire implantaten. Het doel in hoofdstuk 10 is korte termijn resultaten beschrijven van de gecementeerde en ongecementeerde bipolaire Judet radiuskopprothese. Hiervoor werden retrospecti ef de resultaten bekeken van 33 pati ënten met post-traumati sche afwijkingen van de elleboog. Een uitstekend resultaat op de MEPS werd bereikt bij 19 pati ënten, 10 scoorden goed, 1 redelijk en 3 slecht. De mediane score was 100 (range: 55-100). De mediane Elbow Functi on Assessment (EFA) score was 94 (range: 60-100). De mediane bewegingsuitslag van fl exie en extensie was 130°, met een range van 80°-145°. De mediane pro- en supinati e was voor beiden 70°. Deze functi onele resultaten zijn vergelijkbaar met andere studies naar dit implantaat35-40, maar een goede vergelijking is lasti g aangezien de kenmerken (type letsel, begeleidende letsel en revisiechirurgie) van de pati ëntgroepen erg verschillen tussen de verschillende studies. Hoewel de functi onele resultaten van de gecementeerde en ongecementeerde prothese vergelijkbaar waren in deze studie, werd er bij 11 van de 16 (69%) ongecementeerde pro- theses osteolyse gezien van de proximale radius. De klinische relevanti e hiervan is nog onbekend. Een oorzaak van deze osteolyse zou slijtage kunnen zijn van de polyethyleen (PE) component van de bipolaire prothese. Histologisch bewijs hiervoor werd beschreven door O’Driscoll en Herald.41 Deze oorzaak alleen is echter onwaarschijnlijk, aangezien de follow- up (28 maanden) te kort is om signifi cante slijtage te kunnen veroorzaken. Deze osteolyse werd niet gevonden bij gecementeerde implantaten, waarvan de follow-up aanzienlijk lan- ger was (36 maanden). Meest waarschijnlijk is dat het zogenaamde “stress-shielding” aan de basis ligt van dit fenomeen: de korte, rigide steel van de ongecementeerde variant is vatbaarder voor stress-shielding in vergelijking tot de langere, dunnere en meer fl exibele steel van het gecementeerde implantaat.42 Concluderend zijn de functi onele resultaten van de gecementeerde en ongecementeerde bipolaire radiuskopprothese over het algemeen goed, maar is de klinische relevanti e en oorzaak van osteolyse van de proximale radius bij 69% van de ongecementreerde implantaten vooralsnog onbekend. 12 152

COnCLuSIES En AAnbEVELInGEn VOOR TOEKOMSTIG OnDERzOEK

Conclusies Op basis van de studies die in hoofdstuk 3 tot en met 10 van dit proefschrift worden gepresenteerd kunnen we de volgende conclusies trekken: Hoofdstuk 3: Allereerst kunnen we concluderen dat radiuskopfracturen veel voorkomen, met een incidentie in de Nederlandse populatie van 2.8 per 10.000 inwoners per jaar. De man-vrouw ratio was 2:3, waarbij vrouwen significant ouder zijn dan mannen. Dit sug- gereert een mogelijk verband met osteoporose. Begeleidende letsels komen bij 12.4% van de patiënten voor. De behandelend arts dient rekening te houden met deze letsels bij de behandeling van radiuskopfracturen. Hoofdstuk 4: In dit hoofdstuk worden radiuskopfracturen bij vrouwen ≥50 jaar geïdenti- ficeerd als potentiële osteoporotische fracturen. Deze patiënten hadden een verhoogd risico op osteoporose, met een OR van 3.4. Dit kan de typische leeftijdsdistributie verklaren van patiënten met een radiuskopfractuur. Het herkennen van deze fracturen als mogelijk osteoporotische fractuur bij deze patiënten en het aanbieden van een botdichtheidmeting kan de diagnose osteoporose aanzienlijk vervroegen. Hoofdstuk 5 en 6: Begeleidende letsels werden bij 35 van 46 (76%) van de ellebogen met een radiuskopfractuur gevonden met MRI. Letsels van het LCL en capitellum werden het meest gediagnosticeerd. De klinische relevantie van deze letsels bleek echter beperkt: slechts 4% van deze letsels is symptomatisch of van klinische relevantie na een follow-up van 13.3 maanden. Hoofdstuk 7: Letsel van het MCL komt voornamelijk voor bij sporters en bij patiënten met post-traumatische afwijkingen van de elleboog, zoals na een luxatie. De diagnose kan worden gesteld met een MRI arthrogram. De behandeling is afhankelijk van de (atletische) functie-eisen van de elleboog en de ernst van het letsel en bestaat op de eerste plaats uit een conservatief traject. Als conservatieve behandeling faalt kan er gekozen worden voor chirurgische reconstructie van het MCL. De optimale operatieve techniek isnog onderwerp van discussie. Hoofdstuk 8: Slechts enkele studies over de inter- en intra-observer overeekomst van de Mason classificatie of een van de variaties zijn op dit moment beschikbaar, waarvan slechts één over de Mason-Hotckiss classificatie. De inter-observer overeenkomst van de Mason-Hotchkiss classificatie was substantieel en de intra-observer overeenkomst was redelijk tot substantieel met 4 verschillende observers met verschillende niveaus van klinische ervaring. Meer klinische ervaring verbeterde de overeenkomst niet significant. Hoofdstuk 9: Er zijn slechts negen Level IV studies over de behandeling van Mason type II radiuskopfracturen zonder begeleidende fracturen of dislocatie beschikbaar. In deze studies was conservatieve behandeling succesvol bij 80% van de patiënten. Operatieve behandeling middels osteosynthese was succesvol bij 93% van de patiënten. Men moet Nederlandstalige samenvatti ng 153 echter voorzichti g te zijn met het vertalen van deze resultaten naar de dagelijkse prakti jk: de methodologische kwaliteit van de studies is zwak met een korte follow-up, en de studies over de operati eve behandeling promoten voornamelijk een nieuwe operati eve techniek of materiaal. Hoofdstuk 10: De korte termijn resultaten van de gecementeerde en press-fi t Judet bipolaire radiuskopprothese zijn goed bij 86% van de pati ënten met post-traumati sche afwijkingen van het radiuskopje. Bij 69% van de ongecementeerde prothesen wordt echter osteolyse gezien van de proximale radius. De exacte oorzaak, klinische relevanti e en beloop hiervan is nog onduidelijk.

Aanbevelingen voor toekomsti g onderzoek Hoewel de kennis over radiuskopfracturen en zijn begeleidende letsels aanzienlijk is toegenomen in de afgelopen jaren, blijven vele aspecten van radiuskopfracturen nog steeds onderwerp van discussie. In dit academisch proefschrift wordt er een verband gelegd tussen radiuskopfracturen bij vrouwen ≥50 jaar met een radiuskopfractuur en osteoporose, waarmee de typische epidemiologie verklaard kan worden. In hoofdstuk 4 wordt dit ondersteund met een retrospecti eve case-control studie waarbij pati ënten en controles een perifere botdichtheidmeti ng ondergingen, waarbij we een verhoogd risico op osteoporose vonden bij vrouwen met radiuskopfractuur. Prospecti eve studies met grotere pati ëntaantallen zijn geïndiceerd, waarbij de botdichtheidmeti ng wordt verricht met een DEXA-scan (de gouden standaard). In hoofdstuk 9 concludeerden we na een systemati sche review dat er behoeft e is aan prospecti eve, gerandomiseerde studies naar de behandeling van Mason type II radiuskopfracturen (conservati ef vs. ORIF). De pati ëntpopulati e en baseline karakteristi eken zoals leeft ijd, dominanti e, fractuurkenmerken en begeleidende letsels zoals elleboogluxati e, moeten hierbij goed beschreven worden. Data zoals bewegingsuitslagen, re-operati es, pijn en aantal complicati es dienen te worden benoemd. Een follow-up van minimaal 12 maanden is wenselijk. Uitkomstmaten zoals de Broberg en Morrey score, de Mayo El- bow Performance Index en de DASH-score maken de resultaten van onderzoeken meer vergelijkbaar. Deze scores zijn echter nog nooit gevalideerd voor ellebogen met een radiuskopfractuur. De resultaten van radiuskopprothesen bij pati ënten met niet reconstrueerbare radiuskopfracturen zijn over het algemeen goed. Lange termijn resultaten zijn echter schaars. In hoofdstuk 10 worden de resultaten van gecementeerde en press-fi t prothesen besproken met een minimale follow-up van twee jaar. Hierbij werd er bij 69% van de ellebogen met een press-fi t prothese osteolyse gezien van de proximale radius. De oorzaak en klinische relevanti e hiervan zijn onbekend. Studies met lange termijn resultaten van deze prothese zijn nodig om dit te onderzoeken, maar ook biomechanisch onderzoek naar factoren zoals 12 stress-shielding bij radiuskopprothesen zijn noodzakelijk. 154

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(21) Davidson PA, Moseley JB, Jr., Tullos HS. Radial head fracture. A potenti ally complex injury. Clin Orthop Relat Res 1993 Dec;(297): 224-30. (22) Itamura J, Roidis N, Mirzayan R, Vaishnav S, Learch T, Shean C. Radial head fractures: MRI evaluati on of associated injuries. J Shoulder Elbow Surg 2005 Jul;14(4): 421-4. (23) Kaas L, Turkenburg JL, van Riet RP, Vroemen J, Eygendaal D. Magneti c resonance imaging fi ndings in 46 elbows with a radial head fracture. Acta Orthopaedica 2010;81(3): 373-6. (24) Han KJ, Kim YK, Lim SK, Park JY, Oh KS. The eff ect of physical characteristi cs and fi eld positi on on the shoulder and elbow injuries of 490 baseball players: confi rmati on of diagnosis by magneti c resonance imaging. Clin J Sport Med 2009 Jul;19(4): 271-6. (25) Eygendaal D, Verdegaal SH, Obermann WR, van Vugt AB, Poll RG, Rozing PM. Posterolateral dislocati on of the elbow joint. Relati onship to medial instability. J Bone Joint Surg Am 2000 Apr; 82(4): 555-60. (26) Eygendaal D, Safran MR. Postero-medial elbow problems in the adult athlete. Br J Sports Med 2006 May;40(5): 430-4. (27) Timmerman LA, Schwartz ML, Andrews JR. Preoperati ve evaluati on of the ulnar collateral ligament by magneti c resonance imaging and computed tomography arthrography. Evaluati on in 25 baseball players with surgical confi rmati on. Am J Sports Med 1994 Jan; 22(1): 26-31. (28) Schwartz ML, al-Zahrani S, Morwessel RM, Andrews JR. Ulnar collateral ligament injury in the throwing athlete: evaluati on with saline-enhanced MR arthrography. Radiology 1995 Oct; 197(1): 297-9. (29) Retti g AC, Sherrill C, Snead DS, Mendler JC, Mieling P. Nonoperati ve treatment of ulnar collateral ligament injuries in throwing athletes. Am J Sports Med 2001 Jan;29(1): 15-7. (30) Conway JE, Jobe FW, Glousman RE, Pink M. Medial instability of the elbow in throwing athletes. Treatment by repair or reconstructi on of the ulnar collateral ligament. J Bone Joint Surg Am 1992 Jan;74(1): 67-83. (31) Savoie FH, III, Nunley PD, Field LD. Arthroscopic management of the arthriti c elbow: indicati ons, technique, and results. J Shoulder Elbow Surg 1999 May;8(3): 214-9. (32) Bowers AL, Dines JS, Dines DM, Altchek DW. Elbow medial ulnar collateral ligament reconstructi on: clinical relevance and the docking technique. J Shoulder Elbow Surg 2010 Mar;19(2 Suppl):110-7. (33) Akesson T, Herbertsson P, Josefsson PO, Hasserius R, Besjakov J, Karlsson MK. Primary nonoperati ve treatment of moderately displaced two-part fractures of the radial head. J Bone Joint Surg Am 2006 Sep;88(9): 1909-14. (34) Herbertsson P, Josefsson PO, Hasserius R, Karlsson C, Besjakov J, Karlsson M. Uncomplicated Mason type-II and III fractures of the radial head and neck in adults. A long-term follow-up study. J Bone Joint Surg Am 2004 Mar;86-A(3): 569-74. (35) Dotzis A, Cochu G, Mabit C, Charissoux JL, Arnaud JP. Comminuted fractures of the radial head treated by the Judet fl oati ng radial head prosthesis. J Bone Joint Surg Br 2006 Jun; 88(6): 760-4. (36) Judet T. Results of acute excision of the radial head in elbow radial head fracture-dislocati ons. J Orthop Trauma 2001 May;15(4): 308-9. (37) Popovic N, Lemaire R, Georis P, Gillet P. Midterm results with a bipolar radial head prosthesis: radiographic evidence of loosening at the bone-cement interface. J Bone Joint Surg Am 2007 Nov; 89(11):2469-76. (38) Brinkman JM, Rahusen FT, de Vos MJ, Eygendaal D. Treatment of sequelae of radial head fractures with a bipolar radial head prosthesis: good outcome aft er 1-4 years follow-up in 11 pati ents. Acta Orthop 2005 Dec;76(6): 867-72. 12 156

(39) Burkhart KJ, Mattyasovszky SG, Runkel M, Schwarz C, Kuchle R, Hessmann MH, et al. Mid- to long- term results after bipolar radial head arthroplasty. J Shoulder Elbow Surg 2010 Oct; 19(7): 965-72. (40) Celli A, Modena F, Celli L. The acute bipolar radial head replacement for isolated unreconstructable fractures of the radial head. Musculoskelet Surg 2010 May; 94 Suppl 1: S3-S9. (41) O’Driscoll SW, Herald J. Symptomatic failure of snap-on bipolar radial head prosthesis. J Shoulder Elbow Surg 2009 Sep; 18(5): e7-11. (42) Huiskes R, Weinans H, Van RB. The relationship between stress shielding and bone resorption around total hip stems and the effects of flexible materials. Clin Orthop Relat Res 1992 Jan; (274): 124-34. Dankwoord 157

DAnKwOORD

Geachte professor Van Dijk, beste Niek, U zag de mogelijkheden om een ambitie tot promoveren om te vormen in een concreet traject. Zonder mijn jaar als arts-onderzoeker in het AMC zou het waarschijnlijk nog een lange tijd hebben geduurd voordat dit boekje af zou zijn. Tijdens onze besprekingen wist u de manuscripten met kritische vragen en aanvullingen altijd naar een hoger plan te tillen. Daarnaast heeft u ook mijn squash-niveau aanzienlijk weten te verhogen! Hoewel ik inmiddels niet meer werkzaam ben in het cluster AMC, zal ik met veel plezier terugdenken aan de periode dat ik onder uw supervisie heb mogen werken en wil u danken voor het vertrouwen en de begeleiding die u mij gegeven heeft.

Geachte doctor Eygendaal, beste Denise, Toen ik als ANIOS chirurgie in 2007 via Peter Joosten voor het eerst met jou in contact kwam voor een “onderzoekskluif” om mijn curriculum vitae te pimpen, werd al in de eerste vijf minuten de basis gelegd voor dit boekje. Op een Post-It™ velletje werd in grote lijnen de weg uitgetekend naar promotie en opleiding. Jouw grenzeloze ambitie en ongematigd enthousiasme heeft bijzonder aanstekelijk gewerkt. In de afgelopen jaren heb je me de mogelijkheid gegeven om kennis laten maken met alle facetten van de orthopedie en onderzoek: van de dagelijkse kliniek als ANIOS orthopedie tot de jaarlijkse in saté en bier gedrenkte orthopedie-kerstborrels, van het opzetten van onderzoek tot het schrijven van de artikelen en van poster- tot podiumpresentatie op de diverse congressen. Dankzij deze ervaringen en jouw steun is het me uiteindelijk gelukt de “Dubbel” binnen te halen: een promotie én een opleidingsplaats! Ik hoop dat we in de toekomst nog veelvuldig mogen samenwerken, op het gebied van de wetenschap en in de klinische arena.

Geachte leden van de Promotiecommissie, Prof. dr. P.J.E. Bindels, prof. dr. P.M.M. van Bossuyt, dr. M. Maas, prof. dr. F. Nollet, en prof. dr. D.B.F. Saris, veel dank voor het kritisch lezen en positief beoordelen van het proefschrift manuscript.

Beste mede-auteurs, dear co-authors, Leon Elmans, Martijn van Hooft, Jesse Jupiter, Sjaak Kodde, Roger van Riet, David Ring, Inger Sierevelt, Matthijs Somford, Peter Struijs, Jeroen Turkenburg, Jos Vroemen: Thank you very much for your effort, fresh ideas, countless suggestions and comments to improve the quality of the research and writing needed to write the articles that build up this thesis. 158

Beste collega-onderzoekers van de ORCA en dr. ir. Leendert Blankevoort, Christiaan van Bergen, Maayke van Sterkenburg, Tan Nguyen, Mikel Reilingh, Inger Sie- revelt, Gabriëlle Tuijthof, Jan-Joost Wiegerinck en in mijn laatste weekjes Aimee Kok: met veel plezier denk ik terug aan het jaar dat ik in de ORCA-burelen heb gewerkt en hoewel ik toen de kliniek soms erg miste, mis ik nu soms in de kliniek de rust van het onderzoek op G4. Ik ga er vanuit dat we nog menig NOV-feest of congres onveilig mogen gaan maken. Leendert, dank voor de mogelijkheid om te mogen werken bij de ORCA. Ook al was je niet betrokken bij mijn onderzoek, je was als “onderzoeksbaas” altijd toegankelijk voor advies. In het bijzonder dank voor mijn cubicle-genoot Bas van Ooij: een jaar met zijn tweeën op 4 vierkante meter zonder daglicht schept een bijzondere band. Liftmuziek, dubstep, Spotify en wielrennen passeerden veelvuldig de revue. Onze publicatie in de Archivo di Orthopaedia e Rheumatologica als tastbaar bewijs van onze samenwerking in G4-242. Hoewel ik in ons gezamenlijk jaar nooit helemaal duidelijk heb gekregen wat nou exact jouw promotieonderzoek inhield, hoop ik dat spoedig jouw boekje op de deurmat valt.

De maatschap Orthopedie Amphia, Annechien Beumer, Ad van Beurden, Maayke van de Borne, Stefan Bolder, Leon Elmans, Rutger van Geenen, Erik Hoebink, Joost van den Hout, Peter Joosten, Wim van Heeswijk, Erik Moonen, inmiddels aangevuld met nieuwe ‘bazen’, en de afgezwaaide “oude garde”: dr. Kruls, Tordoir, Jolles en Van Ommeren: Dank voor de anderhalf jaar dat ik onder jullie supervisie heb mogen werken als ANIOS. Een bijzonder inspirerende en open werkomge- ving waar ik veel heb kunnen leren over de orthopedie op een ongekend hoog niveau. Ik denk dat er maar weinig plekken in Nederland zijn waar je zoveel kunt zien en leren als bij jullie, en kom dan ook graag nog eens terug in de loop van mijn opleiding!

Polidames Orthopedie Amphia, nurse practioners Margreet Boeve, Yvonne de Deugd en Maryse Shepard, Dames, zonder jullie steun was het lastig geweest om al die statussen vanuit de uit- puilende rekken boven water te halen, poliruimte te regelen voor het terug zien van patiënten, botdichtheidsmetingen te verrichten en al die andere zaken waarmee jullie mij hebben geholpen. Dank hiervoor!

Secretariaat AMC/ORCA, Beste Rosalie en Marga, dank voor jullie ondersteuning bij het regelen van een mo- mentje in de altijd overvolle agenda van de prof en het wegwijs maken in het oerwoud van formulieren en procedures die bij een promotie gepaard gaan. Dankwoord 159

Paranimfen Jérôme Waterval en Bob Eikemans, Beste Jérôme, de basis voor onze vriendschap werd gelegd aan het begin van onze studie. Daarna werden er nog vele avonden sigaren rokend en filosoferend over de goede dingen in het leven doorgebracht in de Oase, op het Oranjeplein of in de Oude Kerkstraat. Onze wetenschappelijke carrière begonnen we samen in het Medisch Centrum Annadal, en inmiddels is er nog steeds een strijd gaande over wie de meeste PubMed publicaties achter zijn naam heeft staan, waarbij met enige regelmaat de laatste score heen en weer wordt ge-sms’t. Ik hoop dat deze spannende strijd nog een tijdje mag doorgaan, maar het mag duidelijk zijn wie er als eerste de Grote Prijs heeft binnen gehaald! Beste Bob, nadat je niet onverdienstelijk ceremoniemeester bent geweest op talloze bruiloften, leek het mij een goed idee om een nieuwe uitdaging aan te gaan: paranimf. Je bent altijd de drijvende kracht achter cantussen, zeilweekenden, whiskeytours in Schot- land en ik twijfel er dan ook niet aan dat je ook deze rol vol bravoure op je zult nemen. Vele legendarische momenten hebben wij doorgebracht. Eerst in Maastricht, later in Breda: de kleintjes pils in café ’t Pumpke met de langspeelplaten van Louis staan voor altijd in het geheugen gegrift. Ik twijfel er ook niet aan dat er nog vele zullen volgen!

Familie, Eerst geografisch ver uit elkaar, maar sinds dat probleem is opgelost heeft onder andere dit project veel tijd gevraagd. Ik kan met dit vak helaas geen garanties geven, maar hoop dat het de komende tijd beter gaat en de contacten eens goed kan aanhalen; te beginnen op het promotiefeest. In het bijzonder wil ik Sandra Kaas, mijn meest kunstzinnige nichtje, de eer geven die ze verdient: onwijs bedankt voor het ontwerpen van deze prachtige kaft en het binnenwerk. De carte blanche die je kreeg voor het ontwerp heeft beyond belief mooi uitgepakt! Toch weer eens wat anders dan suffe röntgenfoto’s of stukken bot op die kaft

Vrienden, Teveel om allemaal afzonderlijk op te noemen, maar toch allemaal even onmisbaar geweest bij de totstandkoming van dit proefschrift door jullie steun en af en toe aanhoren van een kleine klaagzang over het in de afgelopen jaren doorlopen traject. Ook de nodige afleiding waarin jullie voorzagen is bijzonder gewaardeerd! Hoewel iedereen de laatste jaren steeds meer uitwaaiert over het land, blijven we elkaar regelmatig zien en dat blijft toch iedere keer bijzonder en hoop dat het nog lang zo mag blijven.

Beste Bart, Marleen, Gerben, en Yara, Dank voor mijn onbezorgde jeugd die was zoals hij zou moeten zijn: hutten bouwen, door bossen struinen, zeepkisten bouwen, fikkie stoken in de achtertuin en dammen bouwen in 160

de beek voor de deur. Dank voor jullie steun in mijn studententijd en gedurende afgelopen jaren, ondanks dat ik door diensten en onderzoek misschien te weinig mijn gezicht heb laten zien. Ik ga er vanuit dat mijn tochtjes naar het diepe zuiden (met de racefiets in de kofferbak) nu iets frequenter gaan zijn. 2012 gaat een goed jaar worden voor de familie Kaas, met deze promotie en de trouwerij van Gerben en Cindy in het vooruitzicht! 161 bIbLIOGRAPHy

Scientific publications 2007 Schroeter CA, Kaas L, Waterval JJ, Bos PM, Neumann HAM. Succesfull treatment of periungual warts using photodynamic therapy: a pilot study. J Eur Acad Der- matol Venereol 2007; 21: 1170-1174. 2008 Kaas L, van Riet RP, Vroemen JPAM, Eygendaal D. The incidence of traumatic, osseous upper limb pathology in fractures of the radial head. Strat Traum Limb Recon 2008; 3: 71-74. Winner NVOT Biomet research award 2008. 2010 Kaas L, van Riet RP, Vroemen JPAM, Eygendaal D. The epidemiology of radial head. J Shoulder Elbow Surg 2010; 19(4): 520-523. 2010 Kaas L, van Riet RP, Turkenburg JL, Vroemen JPAM, Eygendaal D. Magnetic resonance imaging findings in 46 elbows with a radial head fracture. Acta Orthop 2010; 81(3): 373-376. 2010 Kaas L, van Dijk CN, Eygendaal D. Radiuskopfracturen: de stand van zaken. Neder- lands Tijdschrift voor Traumatologie. 2010; 18(4): 94-99. 2010 van Dijk CN, Kaas L. Arthroscopie van de enkel: indicaties en chirurgische techniek. In dit verband 2010; 20: 10-12. 2010 van Ooij B, Kaas L, Reilingh ML, van Dijk CN. Osteochondral defects of the talus: Surgical treatment and rehabilitation. (Invited review) Arch Orthop Rheum 2010; 121(4): 17-18. 2011 Kaas L, Jupiter JB, van Dijk CN, Eygendaal D. Management of radial head fractures: current concepts. (Invited review) Shoulder & Elbow. 2011; 3(1): 34-40. 2011 Kaas L, Turkenburg JL, van Riet RP, van Dijk CN, Eygendaal D. Radial head fractures: Most injuries detected with MRI not clinically relevant. J Shoulder Elbow Surg 2011; 20(8): 1282-1288. 2012 Eygendaal D, Kaas L. Ulnar collateral ligament instability of the elbow. In: Bhan- dari M. (ed) Evidence-based Orthopedics. 1st edition. Oxford: Wiley-Blackwell; 2012: p. 781-786. 2012 Kaas L, Struijs PAA. Congenital radial head dislocation with a progressive cubitus valgus: a case report. Stat Traum Limb Recon. 2012: In press.

Podium presentations 2008 Kaas L, Van Riet RP, Vroemen JPAM, Eygendaal D. Radiuskopfracturen in de regio Breda: Incidentie van begeleidende ossale letsels van het ipsilaterale bovenste lidmaat. Assistentensymposium Nederlandse Vereniging voor Traumatologie 2008; Soestduinen, 25 January 2008. 162

2008 Kaas L, Van Riet RP, Vroemen JPAM, Eygendaal D. The incidence of traumatic, osseous upper limb pathology in fractures of the radial head. SECEC-ESSSE 2008; Brugge, 18-20 September 2008. 2008 Kaas L, Turkenburg JL, Vroemen JPAM, Eygendaal D. De incidentie van begeleidend letsel bij patiënten met een radiuskopfractuur met MRI. Najaarsvergader- ing NOV; Utrecht, 10 October 2008. 2009 Kaas L. Radiuskopfracturen en begeleidende letsels. CCOC Voorjaarscursus 2009; Amsterdam, 30 January 2009. 2009 Kaas L. Radiuskopfracturen: een gecompliceerd letsel? NVOT Jaarvergadering, Traumadagen 2009; Amsterdam, 5 November 2009. 2009 Kaas L, van Riet RP, Vroemen JPAM, Eygendaal D. De epidemiologie van radiuskopfracturen. Amphia Wetenschapsdag 2009; Breda, 20 November 2009. 2010 Kaas L, Turkenburg JL, van Riet RP, Vroemen JPAM, Eygendaal D. Clinical relevance of MRI findings in 40 elbows with a radial head fracture. NOF 2010, Aarhus, 5-7 May 2010. 2010 Kaas L, Turkenburg JL, van Riet RP, Vroemen JPAM, Eygendaal D. Clinical relevance of MRI findings in 40 elbows with a radial head fracture. ICSES 2010, Edinburgh, 5-8 September 2010. 2011 Kaas L, van Riet RP, van Dijk CN, Eygendaal D. Results of the cemented and press- fit bipolar radial head prosthesis in 35 patients with post-traumatic disorders of the elbow. SECEC-ESSSE 2011; Lyon, 15-17 September 2011.

Poster presentations 2008 Kaas L, Van Riet RP, Vroemen JPAM, Eygendaal D. De incidentie van begeleidend ossaal letsel bij radiuskopfracturen in de Nederlandse populatie. Posterpresenta- tie Amphia Wetenschapsdag, Breda; 31 October 2008. 2011 Kaas L, van Dijk CN, Eygendaal D. Results of the cemented and press-fit bipolar radial head prosthesis in 35 patients with post-traumatic disorders of the elbow. ISAKOS 2011, Rio de Janeiro, 15-19 May 2011. 163

CuRRICuLuM VITAE

Laurens Kaas was born on may 21st 1982 in Heerlen, in the south of the Netherlands. He spent his youth with his parents, older brother and younger sister in Eys. After graduation from high school at the Bernardinuscollege in Heerlen in the year 2000, he started study- ing medicine at Maastricht University and enjoyed his years as a student. After finishing medical school, he moved to the city of Breda, starting as a resident at the department of general surgery of the Amphia Hospital. In 2007 he started with a research project on radial head fractures under the enthousiastic guidance of dr. Denise Eygendaal and in 2008 he switched to the department of orthopaedic surgery at the same hospital. In 2009 he moved to Amsterdam to work full-time on his thesis at the Academic Medical Center, with prof. dr. C. Niek van Dijk as his promoter. During that year, on a very hot day in 2010 (the day of the soccer world cup half-final Brasil vs. the Netherlands) he was accepted for his residency in orthopaedic surgery by prof. dr. Daniël B.F. Saris of the University Medical Center Utrecht. He started his residency in general surgery at the Meander Medical Center at Amersfoort in September 2010, with dr. Adriaan J. van Overbeeke as his supervisor. He is currently living in Zeist and is looking forward to start with his residency of orthopaedic surgery in the Antonius Hospital at Nieuwegein in September 2012.