Elbow Osteoarthritis

Elbow osteoarthritis is a degenerative joint condition in which the cartilage and underlying bone of the elbow gradually change, producing pain, stiffness and mechanical symptoms such as catching or locking. Your elbow is made up of three articulations that share a single joint capsule: the ulnohumeral joint between the ulna and the humerus, the radiocapitellar joint between the radial head and the capitellum, and the proximal radioulnar joint, where the radius and ulna rotate against one another to turn your palm up and down. Osteoarthritis can affect any of these compartments, but the ulnohumeral joint is the one most commonly involved.

Unlike osteoarthritis of the weight-bearing hip and knee, elbow osteoarthritis has a distinctive pattern. Because the ulnohumeral joint surfaces fit together closely, a good proportion of the cartilage is often relatively preserved. The hallmark features instead are widespread osteophytes (small bony spurs), loose bodies — fragments of cartilage and bone that break free inside the joint — and tightening of the joint capsule (Biswas et al., Arthritis, 2013). Spurs typically form first at the tip of the olecranon and coronoid processes and in their matching hollows on the humerus, and loose bodies are a common cause of painful locking or catching when they become trapped between the joint surfaces.

Progression is usually gradual. Early on, pain tends to be felt at the very ends of straightening and bending as the bony spurs engage, with relative comfort through the mid-range — and loss of full extension is classically the first movement to be affected. As the spurs enlarge and the capsule tightens, discomfort is felt across more of the arc and the loss of movement becomes more noticeable. Turning your forearm palm-up and palm-down is often relatively well preserved, because the compartments responsible for rotation are frequently less involved.

There are two broad forms. Primary elbow osteoarthritis is age-related degeneration with no single identifiable cause, and it is uncommon — affecting an estimated 2 to 3% of the population, with an average age at first presentation of around 50 years and the dominant arm involved in roughly 80% of cases (Martinez-Catalan and Sanchez-Sotelo, Journal of Clinical Orthopaedics and Trauma, 2021). A UK study of 1,000 patients found a 2% prevalence of symptomatic elbow osteoarthritis, significantly more common in men and in heavy manual workers (Stanley, Journal of Shoulder and Elbow Surgery, 1994). Secondary, or post-traumatic, osteoarthritis follows an earlier elbow injury such as a fracture into the joint or a dislocation, and can develop in younger people, sometimes years after the original injury.

One clinically important feature is the link with ulnar nerve symptoms. Because spurs and loose bodies tend to form on the inner side of the joint, they can narrow the cubital tunnel through which the ulnar nerve passes, and some degree of ulnar nerve irritation is a common accompaniment to elbow osteoarthritis. Surgical series report ulnar nerve symptoms in a meaningful proportion of patients, and careful clinical examination detects signs of nerve involvement more often still. For this reason, our assessment always includes a careful examination of ulnar nerve function.