Beyond radiographic severity: interrelationship of age, foot progression angle and psychological distress with WOMAC outcome in knee osteoarthritis

Background: Knee osteoarthritis (KOA) is a progressive degenerative joint disorder characterized by chronic pain, functional limitation, and impaired quality of life. Emerging evidence indicates that radiographic severity alone inadequately explains symptom burden, thereby highlighting the contribution of biomechanical and psychosocial determinants to functional disability. The objective is to investigate the interrelationship of age, foot progression angle (FPA), and psychological distress with functional disability measured using the WOMAC Index in patients with knee osteoarthritis. Methods: A cross-sectional observational study was conducted among 108 patients aged 45–70 years with unilateral or bilateral knee osteoarthritis graded using the Kellgren–Lawrence grading system. Functional disability was evaluated using the WOMAC Index, psychological distress using the PHQ-9 and GAD-7, and resilience using the Brief Resilience Scale. Foot progression angle was assessed during gait analysis. Pearson correlation and multivariate linear regression analyses were performed. Results: Advancing age and greater deviations in foot progression angle were significantly associated with worsening WOMAC-derived functional disability. Psychological distress exhibited weak-to-moderate positive correlations with WOMAC outcome, whereas resilience demonstrated an inverse relationship. Multivariate regression analysis identified foot progression angle and psychological distress as independent contributors to functional limitation beyond the effects of radiographic severity. Conclusions: Functional impairment in knee osteoarthritis extends beyond radiographic disease severity and appears to be influenced by gait biomechanics and psychosocial factors. A comprehensive multidimensional assessment may improve individualized rehabilitation and long-term functional outcomes.