Osteoarthritis of the scapho-trapezial joint

In a cohort of 199 patients with OA we studied the prevalence of radiographic scapho-trapezial joint osteoarthritis (STJ OA) and its clinical features. The prevalence of STJ OA was 38%. Lone STJ OA occurs but is uncommon (11%). In contrast, STJ OA in combination with first carpo-metacarpal joint OA was found in 27%. There appears to be an age-related progression from those without disease to lone disease to combined disease. The most frequent radiological features seen were joint space narrowing, subchondral sclerosis and osteophytes. There was a weak correlation between STJ OA and palpable swelling at the thumb base (phi = 0.231, P = 0.01) but no association was found between STJ OA and tenderness at the thumb base.