PurposeThis study aimed to investigate the rate at which patients returned to sports after open wedge high tibial osteotomy and identify the continuity of sports activity post-operatively.MethodsThirty-five patients (40 knees) who underwent open-wedge high tibial osteotomy (OW-HTO) in medial knee osteoarthritis were included in this study. The mean age of the patients who underwent surgery was 55.1 ± 10.7 years, and the mean follow-up period was 41.0 ± 24.7 months. Clinical results and radiographic parameters calculated in standing whole-leg radiographs preoperatively, post-operatively, and at the final follow-up were evaluated.ResultsThirty-one patients (88.6%) were able to return to preoperative sports activity; however, only 14 patients (40.0%) completely returned to preoperative sports activity levels. Of the 31 patients who returned to sports activity, 10 patients (32.3%) maintained post-operative sporting activity levels at the final follow-up. In radiographic parameters, the weight-bearing line ratio was considered loss of correction in the post-operative period leading to the final follow-up. Patients who completely returned to sports and maintained sporting activity levels at the final follow-up had significantly higher the Knee Injury and Osteoarthritis Outcome Score pain subscale values and lower visual analogue scale of knee pain at pre-surgery and final follow-up than other patients, including those who partially returned to sports.ConclusionsThe proportion of patients who returned to sports after OW-HTO and were able to participate in competitions at the same activity level as before surgery was low and insufficient.Level of evidenceRetrospective case series, IV