Five-year outcomes of medial open-wedge high tibial osteotomy with lateral supplemental lag screw in patients with obesity.

BACKGROUND

Obesity contributes to the accelerated progression of knee osteoarthritis. Medial open-wedge high tibial osteotomy (MOWHTO) is a joint-preserving surgical intervention for unicompartmental knee osteoarthritis; however, its efficacy in patients with obesity remains controversial. This study aimed to evaluate the 5-year clinical and radiographic outcomes of MOWHTO with lateral supplemental lag screw fixation in patients with obesity.

MATERIALS AND

METHODS

This retrospective cohort study included patients with obesity who underwent MOWHTO between 2017 and 2020, with a minimum follow-up of 5 years. All procedures were performed by a single surgeon using three-dimensional printed, patient-specific instrumentation, locking plates, and a lateral supplemental lag screw. Clinical outcomes were assessed using the visual analog scale (VAS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Radiographic parameters, including the weight-bearing line percentage (WBL%) and medial proximal tibial angle (MPTA), were evaluated.

RESULTS

Significant improvements in VAS and WOMAC scores were observed at all postoperative time points (p < 0.001) and were accompanied by improved radiographic alignment, with WBL% shifting toward the Fujisawa point and increased MPTA values. At 5 years, mild regression in alignment was noted; however, the overall correction was maintained. The 5-year conversion rate of TKA was 3.8%. Lateral hinge fractures occurred in 3.8% of cases and healed without loss of correction.

CONCLUSIONS

Medial open-wedge high tibial osteotomy is associated with satisfactory 5-year clinical and radiographic outcomes in patients with obesity. Obesity is not necessarily a contraindication for HTO, although appropriate patient selection and long-term follow-up are essential for this procedure.

LEVEL OF EVIDENCE: III, Retrospective cohort study.