Biomechanical and radiographic advantages of double-level osteotomy over single-level osteotomy for medial knee osteoarthritis with double-level deformity: A retrospective analysis.

Abstract

Double-level osteotomy is hypothesized to provide superior biomechanical outcomes compared to single-level osteotomy for medial knee osteoarthritis with double-level deformity. However, its advantages remain underexplored. This retrospective study analyzed 20 knees treated with medial open wedge high tibial osteotomy alone or combined with lateral closed wedge distal femoral osteotomy. Patients were categorized into three groups: Single-level osteotomy for single deformity, single-level osteotomy for double deformity, and double-level osteotomy for double deformity. Radiographic parameters, including Hip-Knee-Ankle angle, mechanical lateral distal femoral angle, medial proximal tibial angle and joint line convergence angle, and gait biomechanics using nine-axis inertial measurement units were evaluated pre- and postoperatively. The postoperative mechanical lateral distal femoral angle was better corrected in the double-level osteotomy for double deformity group compared to the single-level osteotomy for double deformity group (P = 0.012). Peak thigh varus acceleration was significantly reduced in both the double-level osteotomy for double deformity and single-level osteotomy for single deformity groups (P = 0.014), but not in the single-level osteotomy for double deformity group. No significant differences were observed in medial proximal tibial angle among groups. Double-level osteotomy demonstrated superior biomechanical and radiographic outcomes in medial knee osteoarthritis with double-level deformity, emphasizing its role in mitigating joint line obliquity and in optimizing dynamic knee stability.