Objective: To assess the impact of different subsets of symptomatic hand osteoarthritis (OA) on pain and disability.
Methods: From 308 hand OA patients a group with CMCJ symptoms only (group I, n=20) was identified as well as groups with symptoms at the interphalangeal joints (IPJs) only (group II, n=138), and symptoms at both sites (group III, n=150). Hand pain and function, assessed with the AUSCAN, were compared between groups using linear mixed models. Radiological OA was assessed using the Kellgren-Lawrence grading scale.
Results: Mean (SD) AUSCAN scores for group I, II and III were 23.1 (11.7), 18.3 (11.9) and 26.4 (12.5), respectively. After adjustment for age, gender, BMI, family effects and number of symptomatic hand joints, significant differences in AUSCAN scores of 7.4 (95% CI 1.8-13.0) between group I and II, and 5.7 (95% CI 2.7-8.6) between group II and III were found. AUSCAN scores were 5.8 (95% CI 3.1-8.6) higher for patients with versus patients without CMCJ symptoms. Kellgren-Lawrence scores did not differ between groups.
Conclusion: In symptomatic hand OA, CMCJ OA contributes more to pain and disability than IPJ OA. Hence, treatment of CMCJ OA should be emphasized, even if it coincides with IPJ OA.