2021 Volume 36 Issue 5 Pages 705-709
[Purpose] To identify preoperative factors influencing the knee extensor strength after opening wedge high tibial osteotomy (OWHTO). [Participants and Methods] A total of 54 knees of 47 patients (mean age: 60.6 ± 7.2) treated with OWHTO in the study facility were assessed based on the knee extensor strength 1 and 3 years after surgery in comparison with the preoperative Japan Orthopaedic Association score, knee range of motion, and knee extensor strength. Furthermore, the postoperative muscle strength was evaluated by calculating the rate of change from the preoperative value. [Results] The mean rates of improvement in the knee extensor strength 1 and 3 years after surgery compared with the preoperative values were 20.6 ± 47.0% and 32.6 ± 58.8%, respectively; the rate was higher at the latter point. At both points, the preoperative knee extensor strength was the major factor that influenced the rate of change in the knee extensor strength after surgery. [Conclusion] There were more noticeable improvements in the muscle strength after OWHTO among patients with a marked decline in the knee extensor strength before it.