INTRODUCTION

Distal humeral hemiarthroplasty (DHH) was first described in 1947, yet over the past 60 years there have been only a few small series reporting on this technique.^{1,14,17,25–28} Early series reported treatment of a variety of pathologic conditions, including trauma, inflammatory arthritis, and tumor. Prostheses included both custom-made (of various materials) and nonanatomic humeral components from total elbow systems (capitellocondyllar, kudo) and anatomic components (Street). These early surgeries met with mixed results. The past decade has witnessed renewed interest in DHH with advancements in our understanding of elbow biomechanics and with growing experience in the difficulty of achieving effective outcomes in treating complex distal humerus fractures. This technique provides a treatment alternative that bridges the gap between internal fixation and total elbow arthroplasty (TEA) in unsalvageable distal humeral articular surface pathologies.

INDICATIONS AND CONTRAINDICATIONS

The indications for DHH are evolving, both in terms of what is achievable and what is appropriate (Table 52-1). Initial experience has been in the younger patient or the physically active older patient with a comminuted intra-articular distal humeral fracture (sometimes combined with a column fracture) that involves both trochlea and capitellum, where an adequate reduction and internal fixation cannot be achieved. Open reduction internal fixation (ORIF) remains the gold standard of operative treatment; however, patient factors and bone architecture may limit the surgeon’s ability to reconstruct the elbow. Series reporting on ORIF of comminuted intra-articular fractures indicate a substantial rate of unsatisfactory outcomes and a significant complication rate in complex cases.^{1,14,17,23,24}

TABLE 52-1 Indications and Contraindications for Humeral Hemiarthroplasty

INTRODUCTION

Recognition and focused management of radiohumeral joint arthrosis has emerged over the past several years. Herein we describe the concept and the rationale for capitellar replacement, placing this option in the context of other potential nonprosthetic interventions. One feature that characterizes virtually all of these possibilities is the lack of clinical data of outcomes at this point in time. With the next edition of the book, this whole topic will be much better elucidated. The reader should bear in mind that the information offered here is principally to call attention to the process and to highlight emerging options without claiming at this time that this is the ultimate or final solution to the problem.

ETIOLOGY

Like so many other pathologic conditions, it seems as though the process is more frequent once we are attuned to investigate for its presence. In general, as a condition, primarily osteoarthritis at the elbow, generally considered uncommon in the past, is today well recognized in the orthopedic community.^3,6,10,11 Pathology of the radiohumeral joint occurs from primary osteoarthritis, as a sequelae to osteochondritis dissecans, following capitellar fracture, or secondarily to radial head fracture either ignored, treated by open reduction and internal fixation, or by prosthetic replacement. Finally, the condition is seen after split T and Y type of fractures of the distal humerus resulting in malalignment (Fig. 52-8).

FIGURE 52-8 Radiohumeral arthritis with primary involvement of the capitellum after capitellar fracture is treated by resection (A). The distal T-condylar fracture resulting in isolated radiohumeral involvement (B).

The frequency and impact of these various conditions is not readily available in today’s literature. There has been some interesting studies referable to primary osteoarthritis of the radiohumeral joint that are worth noting. Ortner¹³ examined the elbow of a population of Eskimos and South American Indians. As a result of this investigation, the authors describe several forms of osteoarthritis at the radiohumeral joint including (1) hypertrophic bone formation peripheral to the articular surface; (2) hypertrophic bone formation in the radial fossa; (3) increased porosity and hypertrophy of the lateral condylar ridge; (4) porosity of the capitellum and; (5) eburnation of the capitellum. These authors note interestingly and accurately that the narrowing of the ulnohumeral joint is not a characteristic of primary osteoarthritis but is more frequently seen at the radiohumeral joint. On the other hand, the osteophyte formation is more commonly observed in the margin of the trochlea and at the coronoid and tip of the olecranon. Subsequently, Goodfellow et al¹¹ documented the increasing incidence of osteoarthritis of the radiohumeral joint with aging and emphasized the early development of the process at the posterior medial ridge separating the trochlea and the capitellum (Fig. 52-9).⁴ Occupation risks in foundry workers was documented. In general, heavy, repetitive use of the extremity places the joint at risk.

FIGURE 52-9 In some instances joint narrowing of the radiohumeral joint is exhibited as shown by the radiograph and CT (A and B).

Typically, this process appears to be relatively asymptomatic, but with enhanced awareness and closer scrutiny, the presence of radiohumeral joint symptoms is being increasingly appreciated. These observations have been confirmed somewhat in the recent documentation of intervention for primary osteoarthritis of the elbow. Kelly et al⁷ described radiohumeral narrowing and instances in which the ulnohumeral joint was débrided arthroscopically. They noted that the radial humeral involvement often typically appears to be well tolerated and need not be directly assessed. Others emphasize the technical ability to débride the ulnohumeral joint but do not comment to any extent on the radiohumeral joint. Although both closed^7–9 and open procedures^1,14,16 are well-accepted means of treating primary osteoarthritis of the elbow, few make reference specifically to the management of the radial head.^7,9 Radiographically, however, the radial head involvement has been documented by Dalal.² In this study of 50 patients with primary osteoarthritis, radial head involvement was present in approximately 85% but was not typically symptomatic. Some narrowing of the joint was present in approximately 60% compared with only 15% narrowing of the ulnohumeral joint. Savoie’s group is one group that has addressed the radiohumeral component of primary osteoarthritis. These authors perform radial head resection through the arthroscope and, in so doing, document improved motion in both flexion and extension and pronation and supination.⁹ The long-term impact, however, of removing the radial head in the presence of ulnohumeral joint arthrosis is unknown. This is one of the major issues that prompts one to consider possibly replacing this joint if it is symptomatic enough to deserve treatment on its own merits.

TREATMENT OPTIONS

Experience to date on the treatment of isolated radiohumeral arthrosis or particularly a capitellar arthritis is limited. In general, the treatment options include débridement versus reconstruction. The reconstructive options have relatively little data, but these consist of resecting the capitellum, analogous to isolated resection of the radial head but with little data regarding its outcome. Débridement is effective in those with symptomatic osteochondritis dissecans, particularly when the fragment is loose and causing mechanical symptoms (see Chapters 19 and 38).

Biologic interposition arthroplasty or prosthetic replacement of the capitellum and/or the capitellum and radial head is a consideration. When the capitellum has been destroyed as a result of fracture, often with resorption, a unique problem exists for which there is no good solution. We have performed allograft replacement with or without interposition arthroplasty in a few of these patients. We have also performed an anconeus rotational plasty in patients with deficient or arthritic capitellum and this does seem to be an effective modality. This procedure does not, however, provide axial stability.¹² Without question, one of the greatest problems with the radiohumeral joint relates to problems at the articulation after the radial head has been fractured and treated by fixation or prosthetic replacement. Under these circumstances, the radial head is typically excised or the prosthesis is removed. If the medial collateral ligament is stable, this is adequate treatment. If, however, the medial collateral ligament is unstable, then the major indication for consideration of a prosthetic implant exists. This is intended to satisfy the need to stabilize the “lateral column” in instances in which there is deficient medial collateral ligament or axial instability such as an Essex-Lopresti lesion. There is some, but limited, experience with prosthetic replacement to date (Pooley J, personal communication).