Compensatory gait differences between femoral and tibial varus knee Osteoarthritis: Implications for movement and rehabilitation.

Knee osteoarthritis (KOA) with varus deformity can arise from either femoral (FVD) or tibial (TVD) origins, but the differences in compensatory gait patterns between these subgroups remain insufficiently explored, hindering the formulation of targeted rehabilitation strategies. This study aimed to compare three-dimensional lower extremity joint kinematics and spatiotemporal parameters during gait between KOA patients with FVD and TVD, with a focus on implications for movement compensation and rehabilitation. A retrospective cohort of 48 KOA patients with varus deformity (24 FVD, 24 TVD) scheduled for corrective osteotomy underwent preoperative gait analysis using inertial sensors (Noraxon MyoMOTION). Spatiotemporal parameters (stride length, gait speed) and joint kinematics (maximal angles, ranges of motion) of the affected limb in the sagittal, frontal, and transverse planes were compared. Results showed that FVD patients had significantly shorter step length (p < 0.001) and restricted multi-joint mobility (knee flexion, hip abduction, ankle inversion-eversion ROM; all p < 0.05) compared to TVD patients, despite similar varus severity. These findings indicate that the origin of deformity (femoral vs. tibial) determines distinct compensatory gait adaptations, highlighting the need for etiology-specific rehabilitation approaches.