49 High Tibial Osteotomy: Indications, Techniques, and Postoperative Management Chadwick C. Prodromos, MD Annunziato Amendola, MD Roland P. Jakob, MD Abstract partially for economic reasons and par- High tibial osteotomy is a safe and effective treatment for medial compartment arthrosis tially because of a greater interest in of the knee accompanied by varus alignment. This procedure has seen increasing use as an knee repair in other countries. adjunct to cartilage restoration procedures, such as autologous chondrocyte and meniscal Whereas HTO was initially per- allograft transplantation, when angular deformity exists. The overall goals of high tibial formed almost exclusively as a clos- osteotomy can be accomplished by several different techniques. The main indications for ing wedge procedure, in the past two high tibial osteotomy are as a primary treatment for varus gonarthrosis and in conjunc- decades it has come to be performed tion with cartilage restoration procedures, such as autologous chondrocyte implantation or primarily using opening wedge tech- microfracture, where success rates are enhanced by correcting the varus deformity. niques. Initially, external fi xation open- Instr Course Lect 2015;64:555–565. ing wedge procedures were widely used, but more recently, internal fi xation with Prior to the development of total knee “dome” sliding osteotomy also was used limited or large plates has become arthroplasty (TKA) as a reliable proce- by some surgeons.2 More rigid fi xation more popular and external fi xation less dure in the 1980s, high tibial osteotomy with large plates became the dominant common. (HTO) was the most common surgical mode of fi xation in the 1990s. treatment for varus gonarthrosis. The As TKA became more reliable, Indications surgical technique was primarily a clos- HTO was less widely used in the United Medial Pain and Pathology ing wedge osteotomy, often with only a States. However, HTO has remained There is consensus that candidates for staple for fi xation along with a cast.1 A more popular outside the United States, HTO are patients with pain located primarily on the medial aspect of the Dr. Amendola or an immediate family member has received royalties from Arthrex and Arthrosurface; serves as a paid knee and radiographic evidence of me- consultant to or is an employee of Arthrex; serves as an unpaid consultant to MTP Solutions; has stock or stock options dial arthrosis demonstrated by less than held in Arthrosurface and MTP Solutions; and serves as a board member, owner, offi cer, or committee member of the American Academy of Orthopaedic Surgeons; the American Board of Orthopaedic Surgery; the American Orthopaedic 4 mm of medial joint space on a stand- Society for Sports Medicine; and the International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine. ing knee fi lm along with mechanical Dr. Jakob or an immediate family member has received royalties from Geistlich Biomaterials Switzerland and serves as overload associated with a varus defor- a paid consultant to or is an employee of Geistlich Biomaterials Switzerland. Neither Dr. Prodromos nor any immediate family member has received anything of value from or has stock or stock options held in a commercial company or institution mity. Young patients undergoing artic- related directly or indirectly to the subject of this chapter. ular cartilage restoration procedures or © 2015 AAOS Instructional Course Lectures, Volume 64 555 Sports Medicine symptoms) is common and consistent with a good result if the patient clearly identifi es his or her medial knee as the overriding problem. Relative Contraindications and Indications Obesity Coventry et al7 reported poorer results in patients who were 1.32 times heavier than their ideal body weight. Although this does not directly translate to the more commonly used body mass in- dex, this in general translates to a body mass index of 30 or greater. To varying degrees, outcomes have been worse in patients who are obese.8-11 Not only are success rates lower, but complications Figure 2 AP radiograph shows are higher. However, some surgeons an opening wedge osteotomy with a Figure 1 Mechanical axis radio- lateral small plate to fi x the hinge in have achieved good results in patients graph. A line is drawn from the fem- addition to a medial plate. oral head through the center of the who are obese. One of this chapter’s knee, and a second line is drawn authors (CCP) has found obesity to be from the ankle through the center Contraindications an important relative contraindication of the knee. The angle between the lines is the degree of varus or Stiffness to HTO, whereas another author (AA) valgus. A well-aligned knee should A markedly decreased range of motion believes that patients who are obese be 0° (±1°). predisposes patients to poor results. may be better served by osteotomy than This is usually considered fl exion of less arthroplasty. The other author (RPJ) medial meniscal transplantation who than 90°, although less than 100° and has found that HTO may be preferable have the mechanical axis lying within less than 120° also have been reported to TKA in a young patient who is obese. that compartment also are candidates as showing fewer good results.3-6 One of However, care is needed to ensure fi x- for an unloading osteotomy. It is gen- this chapter’s authors (RPJ) found that ation stability using techniques such as erally agreed that no lateral pain should stiffness in younger patients is caused a small lateral plate to fi x the hinge, in exist preoperatively. by posterior condylar osteophytes; good addition to a medial plate (Figure 2). outcomes are possible if the osteophytes Preoperative Varus are removed concurrently. Smoking For HTO to be indicated, some degree Many authors have reported higher of preoperative varus must exist. It is Symptomatic nonunion rates in patients who smoke; essential to measure alignment on long, Patellofemoral Disease this is an even greater concern when hip-knee-ankle mechanical axis radio- The presence of patellofemoral pain performing opening wedge techniques. graphs (orthoradiograms) (Figure 1). and arthrosis is often a concern when Among opening wedge osteotomy pro- There is no consensus on the minimum deciding on whether to perform an cedures, the risk of nonunion is partic- amount of varus that indicates the need osteotomy; however, in the experience ularly high when external fi xators are for HTO. Patients with as little as 4° of this chapter’s authors, it is not a con- used and the procedure is performed of varus of the mechanical axis and traindication. Patellofemoral pathol- below the tibial tubercle. Many sur- unicompartmental medial disease can ogy (articular cartilage attrition in the geons decline to perform HTO on benefi t from HTO. absence of substantial patellofemoral a patient who smokes.12-15 If HTO is 556 © 2015 AAOS Instructional Course Lectures, Volume 64 High Tibial Osteotomy: Indications, Techniques, and Postoperative Management Chapter 49 believed to be indicated in a patient who smokes, a closing wedge osteotomy per- formed above the tubercle with a plate may be the best option. Alternatively, a cancellous graft can be used in an open- ing wedge HTO if the opening exceeds 8 to 9 mm. Age Younger patient age is a relative indi- cation and one of the key factors in the decision to perform HTO. In the Unit- ed States, the generally accepted max- imum age of a patient considered for HTO is 60 years, with TKA preferred in older patients.16 Outside the United States, HTO is often performed in older patients who are physically fi t and have been informed that their pain will be Figure 4 Preoperative mechan- diminished but likely not eliminated. Figure 3 Illustrations of pres- ical axis AP radiograph with the sure applied for a valgus stress mechanical axis deviation shown. view (A) and a varus stress view Female Sex (B). Radiographs show the same It was believed that female sex is a rela- knee with valgus (C) and varus (D) lines is measured. The lower extremi- tive contraindication for HTO because stress. The lines show the align- ties must be equally rotated. Valgus and ment changes. of the possibility of unsightly excessive varus stress views may be used to show postoperative valgus alignment for the thickness of the medial and lateral which women may have a lower toler- the main indications for HTO are met, compartment of the articular cartilage ance. It is, however, important to dis- most patients can be expected to ben- and provide an index of the amount cuss this possibility with all patients to efi t from the procedure, although it is of ligamentous stretching (Figure 3). avoid dissatisfaction because of poor important to take all these factors into This often adds an additional 2° to 3° cosmesis in an otherwise relatively consideration when discussing options to the actual deformity, which can be painless knee. With current techniques with a patient. sub tracted from the total angular cor- that make substantial overcorrection HTO is generally believed to be con- rection or overcorrection results. The unlikely, the sex of the patient is less traindicated in patients with an infl am- size of the opening wedge should be of an issue. matory arthropathy. calculated from the preoperative radio- graphs, and magnifi cation should be Other Surgical Technique taken into account. An example of this Patients younger than 50 years who have Preoperative Planning preoperative planning technique and better preoperative knee function and Obtaining full-length, weight-bearing, the fi nal results are shown in Figures range of motion usually have the best mechanical axis hip-knee-ankle radio- 4, 5, and 6. This information is used outcomes. Ligamentous instability and graphs is mandatory (Figure 1).