Hybrid Closed Wedge High Tibial Osteotomy Maintains the Leg Length after Surgery Compared to Open Wedge High Tibial Osteotomy

Abstract

Abstract Background: Hybrid closed wedge high tibial osteotomy (h-CWHTO) is an improved surgical technique compared with conventional CWHTO that can help reduce the amount of bone block removed. To our best knowledge, there are no reports on changes in leg length after h-CWHTO. This study aimed to assess the change in leg length after open wedge high tibial osteotomy (OWHTO) and h-CWHTO and verify whether the change in leg length was associated with preoperative radiographic factors and the opening or closing of bone distance.Methods: We retrospectively evaluated the data of patients treated via OWHTO and h-CWHTO between 2016 and 2019. Data from 57 cases of OWHTO and 31 cases of h-CWHTO were included in the analysis. Standing full-length anteroposterior radiographs were obtained preoperatively and one year postoperatively. Changes in the lower leg and tibial length were measured using radiography, and the opening or closing of the bone distance was decided via operative planning. Flexion contracture was examined preoperatively and one year postoperatively using a goniometer, and the correlation factors and changes in leg length were analyzed using Spearman’s rank correlation.Results: In the OWHTO group, the lower leg was significantly longer by a mean of length of 6.0±8.7 mm; however, a significant difference was not observed in the h-CWHTO group (mean, -0.56±11.6 mm). Additionally, flexion contracture significantly improved from -7.1±7.0 degrees to -4.7±6.2 degrees in the h-CWHTO group alone. There were no radiographic factors or bone opening or closing distances associated with changes in leg length.Conclusion: While OWHTO extended the lower leg, h-CWHTO could maintain the leg length after surgery. The changes in leg length after OWHTO and h-CWHTO were not predictable based on the preoperative factors.Level of Evidence: Level Ⅲ Retrospective Cohort Study