Background: The ability to return to previous level of sports activity after medial opening wedge high tibial osteotomy (MOWHTO) is an important factor in surgical prognosis. However, little research has been conducted to determine what factors influence this. Methods: A comparison was made between patients who were exercising at their previous level of daily exercise more than 2 years after MOWHTO and those who had not recovered to their previous level. Demographic data, preoperative and postoperative clinical scores, and radiological parameters were compared retrospectively to find significant dif-ferences. The clinical scores used were Knee Injury and Osteoarthritis Outcome Score, Tegner activity scale score, and Short-Form 36 questionnaire. The hip?knee?ankle angle, posterior tibial slope, and medial proximal tibial angle were used to compare radiological parameters. Results: A total of 97 patients were enrolled in the study. Seventy-four patients returned to their previous level of sports activity, and 23 patients did not. There was a significant difference in gender among the demographic data. The preop-erative and postoperative Tegner activity scale scores were significantly different among the clinical scores. Radiological parameters did not differ significantly between...