OBJECTIVE: To evaluate associations between constitutional morphological features and specific radiographic phenotypes of hip OA. METHOD: A cross-sectional study of 566 symptomatic unilateral hip OA cases referred for joint replacement was conducted using the Genetics of Osteoarthritis and Lifestyle (GOAL) database. Unaffected hips of cases were assumed to reflect pre-OA innate constitutional morphology of the contralateral affected hip. Radiographic OA phenotypes in affected hips were classified by the site of minimum joint space width (JSW). Tertiles were used to examine dose response. Odds ratios (ORs) with 95% confidence intervals (CI) adjusted for confounding factors were calculated using logistic regression. RESULTS: Among the 14 morphological features studied, the odds of superolateral, superior intermediate, and superior indeterminate hip OA decreased as the tertiles for acetabular depth (AD) and centre-edge angle (CEA) increased. In contrast, higher mid-centre distance (MCD) showed a positive dose response with all superior hip OA patterns, especially the superolateral and superior intermediate patterns (OR 5.17 95% CI 2.18-12.23 and OR 5.05 95% CI 1.98-12.90, respectively). Sourcil angle (SA) associated with superolateral (OR 3.27 95% CI 1.47-7.26), and superior intermediate patterns (OR 2.39 95% CI 1.01-5.68). Neck shaft angle (NSA) associated with superolateral patterns (OR 2.14 95% CI 1.01-4.71. Femoral head to femoral neck ratio (FHNR) associated with the superomedial pattern (OR 4.22 95% CI 1.49-11.89). CONCLUSIONS: Person-specific pre-OA morphological features associate with different phenotypes of hip OA based on the site of minimum JSW. Further prospective studies are required to confirm these findings.
Jiao et al. (Fri,) studied this question.