Outcome measures in clinical studies of ankle osteoarthritis: a systematic review.

OBJECTIVE: To explore and describe the outcome measures reported in primary research of ankle osteoarthritis (OA) and to propose aligned health-related domains.

METHODS: Six databases were searched, and studies were screened by two independent reviewers. Studies of participants with ankle OA who were> 18 years of age and reported outcome measure data were included. Non-English, animal, cadaveric, reviews, and studies with< 5 participants were excluded. Outcome measures were examined for content and mapped to health-related domains.

RESULTS: 1386 studies were identified, of which 547 met selection criteria - reporting 250 outcome measures. Most commonly reported measures were the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale (n = 257 studies), plain radiographs to measure ankle alignment (n = 211), numerical rating scale for pain severity (n = 177) and goniometry to measure ankle range of motion (n = 148). Outcome measures were organised into 19 domains. The most common domains were pain severity (315 (58%) studies), ankle alignment (254 (46%)), ankle motion (181 (33%)), disability (169 (31%)) and health-related quality of life (128 (23%)). These domains fell into the Outcome Measures in Rheumatology (OMERACT) core areas of life impact and pathophysiological manifestations.

CONCLUSION: Many outcome measures are used in ankle OA research, most of which assess joint alignment, pain, and motion. Based on the outcome measures identified, we proposed 19 possible health-related domains, predominantly in the OMERACT core areas of life impact and pathophysiological manifestations of ankle OA. Clinicians and researchers can use this review in guiding selection of outcome measures.