This study examines osteophyte distribution using three dimensional CT scans in patients with symptomatic primary osteoarthritis of the elbow. The authors reviewed the scans of 22 patients with symptomatic arthritis. They found that ulnohumeral osteophytes were present in 95% of patients; radiohumeral osteophytes were present in 60% of patients. The authors note that despite cadaveric and biomechanical studies which suggest that the radiohumeral joint appears to be more prone to wear and stress than the ulnohumeral joint, the ulnohumeral joint shows significantly higher percentages of osteophytes using advanced imaging.
The significance of this study is twofold. First, it challenges the conventional belief that primary osteoarthritis starts on the radiocapitellar side of the elbow and progresses over to the ulnohumeral articulation. In addition, it suggests that at least in symptomatic patients, ulnohumeral osteophytes are a more significant finding than those between the radial head and the capitellum. The main limitation of the study is that it evaluated only osteophytes and not specifically cartilage wear. Cartilage loss on the load bearing surface of the radial head against the capitellum is not uncommon in patients with osteoarthritis. It remains unclear if this articulation still is the “wear generator” in primary osteoarthritis of the elbow.