Abstract
INTRODUCTION: Opening wedge high tibial osteotomy (OWHTO) and double-level osteotomy (DLO) are commonly performed for correcting large varus knee deformities. This retrospective cohort study compares long-term functional outcomes, complication rates, and survival rates between these two techniques. MATERIALS AND METHODS: Sixty patients who underwent OWHTO (n = 32) or DLO (n = 28) for varus knee correction were evaluated. Outcome measures included the Knee Society Score (KSS) and KSS function score at 1, 5, and 10 years, with percentage improvements analyzed across intervals. Additional measures included hip-knee-ankle (HKA) alignment accuracy, complication rates, and survival rates. Trend analysis was based on 10-year data for OWHTO and 5-year data for DLO. RESULTS: DLO demonstrated significantly higher HKA correction accuracy and fewer complications compared to OWHTO, including reduced incidence of joint line obliquity (JLO) (P = 0.001), posterior tibial slope (PTS) change (P = 0.013), and worsening patellofemoral arthritis (PFA) (P = 0.03). KSS improvements were observed in both groups at all intervals, with DLO showing superior KSS Function scores, suggesting higher functional stability. Percentage improvement trends favoured DLO for specific outcomes over the long term. CONCLUSION: DLO provides more accurate HKA alignment with lower complication rates in JLO, PFA, and PTS changes, while both procedures yield comparable overall KSS scores. The enhanced KSS Function outcomes with DLO indicate a potential clinical advantage in maintaining higher functional activity and patient satisfaction over time. These findings support the use of DLO for patients requiring precise correction of significant varus deformities with sustained functional benefits.