Medial compartment knee contact force during gait reflects symptom severity in advanced knee osteoarthritis.

Purpose: Patients with moderate-to-severe knee osteoarthritis commonly adopt altered gait patterns. A better understanding of how the medial compartment knee contact force during specific phases of gait reflects symptom burden and functional limitations may clarify the biomechanical mechanisms underlying disease progression. This study aimed to investigate the correlation between medial compartment knee contact force during gait and physical function, patient-reported outcome measures, and imaging findings in patients with knee osteoarthritis. Methods: Thirteen patients with advanced knee osteoarthritis (Kellgren-Lawrence grade ≥3) walked a 5-m path at a self-selected speed. Physical function was assessed using passive knee range of motion, muscle strength, pain scores, and walking speed. Self-reported outcomes and imaging data, including medial meniscal extrusion and quadriceps measurements were obtained. Gait kinematic data were collected using markerless motion capture, and the knee contact forces were estimated using a musculoskeletal modeling system. Results: The medial compartment knee contact forces during early and late stance were 1340.45 N and 984.54 N, respectively. Late stance force showed significant negative correlations with knee flexion range of motion and symptom scores (r < -0.737 and r < -0.604, respectively; P < 0.05). No correlations were observed in the early stance force. Conclusions: Greater medial knee contact force during the late stance phase was correlated with reduced mobility and greater symptom severity. Late-stance mechanics may be a valuable target for knee osteoarthritis management.