Medial open-wedge high tibial osteotomy demonstrates an 85.9% non-conversion rate and 76.8% patient satisfaction at a minimum follow-up of 10 years.

Abstract

To evaluate long-term survival and functional outcomes following medial open wedge high tibial osteotomy (MOWHTO) using a locking plate. One hundred fifty-four patients underwent MOWHTO for isolated medial compartment osteoarthritis at Martin Luther Hospital, Berlin, Germany. After application of the predefined inclusion and exclusion criteria, 26 patients were excluded, leaving 126 eligible patients. Of these, two patients had died, and 18 were lost to follow-up. The primary endpoint was survival, defined as the absence of conversion to total knee arthroplasty (TKA). Secondary outcomes included patient-reported outcome measures (Knee Injury and Osteoarthritis Outcome Score [KOOS]), pain, satisfaction, sporting activity (Tegner scale) and complications. Kaplan-Meier analysis was performed for survival, and potential risk factors for conversion were analysed. The mean follow-up was 13.3 years (range, 10.2-18.3). A total of 99 patients were assessed at a mean follow-up of 13.3 years (range, 10.2-18.3), comprising 35.4% women and 64.6% men. The mean age was 48.4 ± 8.3 years at the time of surgery and 61 ± 8 years at final follow-up. The cumulative non-conversion rate was 91.9% at 5 years, 85.9% at 10 years and 80.8% at final follow-up (13.3 years). Patients in the conversion group were significantly older (64.89 ± 8.0 years) than those in the non-conversion group (60.0 ± 7.6 years, <i>p</i> = 0.017). Female sex (<i>p</i> = 0.287), body mass index (BMI, <i>p</i> = 0.404), smoking (<i>p</i> = 0.647), patellofemoral cartilage damage (<i>p</i> = 0.254) and lateral cartilage damage (<i>p</i> = 0.492) were not significantly associated with conversion. KOOS subscales at follow-up reached or exceeded published Patient Acceptable Symptom State thresholds. Mean pain scores were 1.4 at rest and 2.7 during walking. Overall satisfaction was 76.8%, with significantly higher satisfaction among patients without conversion (83.8%) compared to those with conversion (47.4%, <i>p</i> = 0.002). Sports participation decreased significantly, with Tegner scores declining from 4.7 to 3.8, although most patients remained physically active (<i>p</i> = 0.001). The overall complication rate was 12.1%, with overcorrection being the most common event. MOWHTO with angular-stable fixation demonstrated high long-term survival, favourable functional outcomes and high patient satisfaction. Patients in the conversion group were significantly older than those in the non-conversion group. These findings suggest that MOWHTO is a safe and effective joint-preserving procedure in appropriately selected patients with varus malalignment and medial compartment osteoarthritis. Level IV.