Long-Term Clinical Results of Unicompartmental Knee Arthroplasty in Patients Younger than 60 Years of Age: Minimum 10-Year Follow-up

PURPOSE: To evaluate the long-term clinical results and survivorship of unicompartmental knee arthroplasty (UKA) in patients younger than 60 years of age. MATERIALS AND METHODS: One hundred and six cases of medial UKA with a minimum follow-up of 10 years were selected for this study. There were 80 patients and the preoperative diagnosis was osteoarthritis in all cases. The mean age of the patients was 54.2 years and the mean duration of follow-up was 12.1 years. Clinical assessments were performed using the Knee Society clinical rating system, and a survival analysis was performed using the Kaplan-Meier method. RESULTS: The mean knee and function scores improved from 52.8±8.4 points and 56.6±10.6 points preoperatively to 85.4±9.1 points and 84.7±10.4 points at the last follow-up, respectively (p<0.001). The mean range of motion was recovered from 130.7° to 132.8° at the last follow-up. Complications occurred in 20 cases (16.7%) and the most prevalent complication was mobile bearing dislocation (n=9, 7.5%). The 10-year survival rate was 92.8% when conversion to total knee arthroplasty was defined as failure, whereas 89.3% when failure was defined as all revision surgeries. CONCLUSIONS: The long-term clinical results of UKA were satisfactory in patients under 60 years of age. Therefore, UKA could be a useful method for the treatment of medial compartment osteoarthritis of the knee in patients younger than 60 years of age.