Medial opening wedge high tibial osteotomy (MOWHTO) is a well-accepted procedure, which has been widely used for pain relief and varus deformity correction in the osteoarthritic (OA) knee, especially in the young patient. However, in the elderly patient, the efficacy of this procedure is still unknown. Therefore, this study aims to evaluate the survivorship of MOWHTO in elderly patients as the primary outcome. The secondary outcome is to evaluate the loss of correction angle that is the common complication after MOWTHO.
A retrospective study of 50 elderly patients (≥ 60 years) was conducted to track survivorship of MOWHTO. All patients were diagnosed with varus OA knee and underwent MOWHTO at our institute. The patients who had previous knee surgery or incomplete data were excluded. Medical records and radiographs of eligible patients were reviewed for recruiting the data. Survivorship of MOWHTO was analyzed using Kaplan-Meier curves. The starting point was the time of operation and the end point was the time of subsequent TKA. The loss of correction angle was defined as the change of medial proximal tibial angle (MPTA) between three months and one year post-operatively.
The mean age of patients was 66 ± 5.0 years. The majority of patients were female (74%). The mean correction angle was 10.6 ± 3.6 degrees. The union rate of osteotomy site was 100%. In survival analysis, the median follow-up time was 6.0 ± 3.0 years. Two patients required subsequent conversions to TKA. The survivorship of MOWHTO at four years was 95.5% (95%CI, 96.0 to 98.0). For radiographic assessment, the loss of correction angle was 1.0 ± 0.5 degrees at one year post-operatively.
This study proved that MOWHTO in patient ≥60 years had good mid-term survivorship with acceptable complications. This procedure can be the alternative option for the treatment of varus OA knee in the elderly.