Definition

In the simplest of terms, arthritis of the elbow reflects a loss of articular cartilage in the ulnotrochlear and radiocapitellar articulations. Destruction of the articulating surfaces and bone loss or, alternatively, excess bone formation in the form of osteophytes can be present. Joint contractures are common. Joint instability can result from inflammatory or traumatic injury to the bone architecture, capsule, and ligaments. The spectrum of disease ranges from intermittent pain or loss of motion with minimal changes detectable on radiographs to the more advanced stages of arthritis with a limited, painful arc of motion and radiographic demonstration of osteophyte formation, cysts, and loss of joint space. Ultimately, these destructive processes may result in complete ankylosis or total instability of the elbow.

The major causes of elbow arthritis are the inflammatory arthropathies, of which rheumatoid arthritis is the predominant disease. Arthritis of the elbow eventually develops in approximately 20% to 50% of patients with rheumatoid arthritis [1]. Involvement of the elbow in juvenile rheumatoid arthritis is not uncommon. Other inflammatory conditions affecting the elbow joint are systemic lupus erythematosus, the seronegative spondyloarthropathies (ankylosing spondylitis, psoriatic arthritis, Reiter syndrome, and enteropathic arthritis), and crystalline arthritis (gout and pseudogout). Post-traumatic arthritis may result from intra-articular fractures of the elbow. Osteonecrosis of the capitellum or trochlea, leading to arthritis, has also been described [2,3]. Primary osteoarthritis of the elbow is a rare condition, responsible for less than 5% of elbow arthritis [4]. Interestingly, the incidence is significantly higher in the Alaskan Eskimo and Japanese populations [5]. Primary elbow arthritis usually affects the dominant arm of men in their 50s. Repetitive, strenuous arm use appears to be a risk factor; primary elbow arthritis has been reported in heavy laborers, weightlifters, and throwing athletes. Synovial chondromatosis is another rare cause of elbow arthritis [3].

Symptoms

The symptoms of elbow arthritis reflect, in part, the underlying etiology and severity of the disease process. Regardless of the etiology, however, the inability to fully straighten (extend) the elbow is a nearly universal complaint of patients with elbow arthritis. Associated symptoms of cubital tunnel syndrome (ulnar neuropathy at the elbow) include numbness in the ring and small fingers, loss of hand dexterity, and aching pain along the ulnar aspect of the forearm. Cubital tunnel syndrome is neither uncommon nor unexpected, given the proximity of the ulnar nerve to the elbow joint (see Chapter 27).

Patients with early rheumatoid involvement complain of a swollen, painful joint with morning stiffness. Progressive loss of motion or instability is seen in later stages. Compression of the posterior interosseous nerve by rheumatoid synovitis can occasionally produce the inability to extend the fingers.

Patients with crystalline arthritis of the elbow may complain of severe pain, swelling, and limited motion; an expedient evaluation is warranted to rule out a septic elbow in such cases.

Post-traumatic or idiopathic arthritis of the elbow, in contrast, usually is manifested with painful loss of motion without the significant effusions, warmth, or constant pain associated with an inflamed synovium. These patients usually complain of pain at the extremes of motion secondary to osteophyte impingement, and they typically have more trouble extending the elbow than flexing it. Pain throughout the arc of motion implies advanced arthritis. The final stages of arthritis, irrespective of cause, can include complaints of severe pain and decreased motion that hinder activities of daily living as well as the cosmetic deformity of the flexed elbow posture.

Physical Examination

Physical examination findings vary according to the cause and stage of the elbow arthritis. A flexion contracture is almost always present. The range of motion should be monitored at the initial examination and at subsequent follow-up examinations.

Normal adult elbow range of motion in extension-flexion is from 0 degrees to about 150 degrees; pronation averages 75 degrees, and supination averages 85 degrees. A functional range of motion is considered to be 30 to 130 degrees, with 50 degrees of both pronation and supination [6].

All other joints should be assessed as well. Strength should be normal but may be impaired in long-standing elbow arthritis because of disuse or, in more acute cases, pain. Weakness may also be noted in the presence of associated neuropathies. In the absence of associated neuropathies, deep tendon reflexes and sensation should be normal.

Associated ulnar nerve irritation can produce a sensitive nerve with the presence of Tinel sign over the cubital tunnel, diminished sensation in the small finger and ulnar half of the ring finger, and weakness of the intrinsic muscles (see Chapter 27). Numbness provoked by acute flexion of the elbow for 30 to 60 seconds is a positive elbow flexion test result.

Effusions, synovial thickenings, and erythema are commonly noted in the inflammatory arthropathies during acute flares. Loss of motion in flexion and extension as well as in pronation and supination can be present because the synovitis affects all articulating surfaces in the elbow. Pain, limited motion, and crepitus worsen as the disease progresses. On occasion, rheumatoid destruction of the elbow will produce instability, which may be perceived by the patient as weakness or mechanical symptoms. Examination of such elbows will demonstrate laxity to varus and valgus stress; posterior instability may also be seen.

In contrast, progressive primary or post-traumatic arthritis of the elbow results in stiffness. The loss of extension is usually worse than the loss of flexion. Pain is present with forced extension or flexion. Crepitus may be palpable throughout the arc of flexion-extension or with forearm rotation.

Functional Limitations

The elbow functions to position the hand in space. Significant loss of extension can hinder an individual’s ability to interact with the environment, making activities that require nearly full extension, like carrying groceries or briefcases, painful. Significant loss of flexion can interfere with activities of daily living such as eating, shaving, and washing. A normal shoulder can compensate well for a lack of pronation, whereas a normal shoulder, wrist, and cervical spine can compensate, albeit awkwardly, for a lack of full elbow flexion. There is no simple solution for a significant lack of elbow extension; the body must be moved closer to the desired object. Compensatory mechanisms are often impaired in patients with rheumatoid arthritis, magnifying the impact of the elbow arthritis on function.

Diagnostic Studies

Anteroposterior, lateral, and oblique radiographic views of the elbow are usually sufficient for diagnosis of elbow arthritis. The radiographs should be inspected for joint space narrowing, osteophyte and cyst formation, and bone destruction. For the rheumatoid patient, the Mayo Clinic radiographic classification of rheumatoid involvement is useful (Table 21.1) [7]. Dramatic loss of bone is evident as the disease progresses (Fig. 21.1). This pattern of destruction is not seen, however, in the post-traumatic or idiopathic patient. Radiographic features in these patients include spurs or osteophytes on the coronoid and olecranon, loose bodies, and narrowing of the coronoid and olecranon fossae (Fig. 21.2).