Primary Osteoarthritis of the Elbow

Introduction

Over the years since the first edition of this book, primary degenerative arthritis of the elbow is now both well recognized and readily treated. While the pattern of articular changes of the elbow with aging has been studied, from a practical perspective we consider this a “marginal disease.” That is, a consistent pattern of osteophyte formation forms a rim around the margins of the humeral, ulnar, and radial articular surfaces with maintenance of the joint space ( Fig. 76.1 ). This is the basis of the treatment that consists of débridement of these osteophytes, which are responsible for impingement pain and motion loss.

Incidence and Etiology

Primary osteoarthritis of the elbow has been reported as accounting for 1% to 2% of patients presenting with elbow arthritis. Doherty and Preston reported an incidence of about 7% from a typical rheumatologic practice, and there is some evidence that the actual incidence of the disease may be increasing ( Fig. 76.2 ). The etiology as an overuse condition is well recognized, but other predisposing conditions such as osteochondritis dissecans have been implicated.

Clinical Presentation

Men are more commonly affected at a ratio of about 4 : 1. The age at initial presentation is about 50 years, but we have observed a surprising variation ranging from 20 to 65 years. Repetitive use of an extremity is a common finding. In addition to occupational predisposition, it also occurs in those requiring the use of crutches or a wheelchair. The dominant extremity is involved in about 80% of cases, and bilateral involvement is present in 25% to 60%. The radiohumeral joint is involved in about 85% of cases, but it may not be symptomatic.

Some degree of extension loss is a consistent feature, but mild to moderate pain is also commonly present ( Fig. 76.3 ). Pain in terminal extension is the symptom that most commonly prompts intervention. Less commonly, symptoms are present throughout the arc. The radiohumeral joint is symptomatic in about 50% of patients. Hence, forearm rotation is not typically restricted or only minimally so. Because the disease is characterized by marginal osteophytes, ulnar nerve irritation is observed in at least 10% of patients and we suspect in a higher number if carefully examined. Ulnar nerve involvement should be specifically sought in the examination because it influences treatment decisions and even long-term outcome.

Diagnosis

Today the clinical and radiographic features are well known so arthrocentesis, extensive blood work, or synovial biopsy are no longer routinely performed. The sedimentation rate is normal.

The roentgenographic study is diagnostic, and typically no other assessment is indicated or required.

Radiographic Features

The roentgenographic features of this condition are classic and characteristic, maybe even monotonous. Of note, the characteristic of primary osteoarthritis is “marginal osteophyte formation.” Hence, the anteroposterior and lateral roentgenograms reveal an osteophyte of the coronoid and olecranon processes ( Fig. 76.4 ). Loose bodies are also frequent and characteristic of this process. No other study is required to make this diagnosis. However, prior to débridement a computed tomography scan is helpful to accurately demonstrate the size and extent of osteophyte formation and the presence and location of loose bodies ( Fig. 76.5 ). The anteroposterior plane film view also shows a consistent finding of ossification and osteophyte formation in the olecranon or coronoid fossa ( Fig. 76.6 ). Involvement of the radial head has been documented in about 85% of cases. A cubital tunnel view is sometimes obtained if the ulnar nerve shows signs of ulnar neuritis. The radiographic features do reflect the clinical expression and provide a guideline to treatment.

Treatment