Altered gait strategies show inconsistent medial compartment unloading in varus medial knee osteoarthritis awaiting high tibial osteotomy

Background

Medial knee osteoarthritis is increasingly diagnosed in younger adults who are often unsuitable for joint replacement. High tibial osteotomy corrects varus malalignment but is invasive. Gait retraining is a low-cost, non-surgical option to reduce medial tibiofemoral loading, but its effects in varus deformity are unclear. We quantified the immediate biomechanical effects of short-term gait modifications on internal tibiofemoral loading.

Methods

Twenty-nine patients (30 knees) with medial knee osteoarthritis scheduled for high tibial osteotomy performed three modified gaits: toe out, wide base, and medial thrust. Motion capture and musculoskeletal modelling estimated internal tibiofemoral joint forces in this pre- high tibial osteotomy, varus-aligned cohort.

Findings

Toe out increased medial loading in early stance but reduced it in late stance. Wide base increased medial and lateral forces early, then reduced medial loading later with compensatory lateral increases. Medial thrust was difficult: only 20/30 knees achieved the target reduction in maximum knee adduction angle, and successful trials still increased early-stance loading. Overall effects were modest, phase-specific, and inconsistent.

Interpretation

Generic gait modifications produced small, phase-dependent changes in internal tibiofemoral loading, with early-stance increases, late-stance reductions, and occasional compensatory lateral loading. Longer-term, individualised retraining incorporating symptoms is needed to determine net clinical benefit.