Which Unicondylar Prosthesis Has Better Mid-Term Results: Fixed or Mobile?

Abstract

Objective: Osteoarthritis, which is one of the most common causes of pain and motion loss, is an important medical disease that particularly affects elderly people. Unicondylar knee arthroplasty treatment is still a challenge for obese and/or ACL deficient patients. In addition, surgeons have difficulty in decision making whether to use fixed or mobile bearing designed unicompartmental knee prosthesis. The objective of this study was to evaluate the effect of fixed or mobile insert design prosthesis on the mid-term results of patients that were followed up for 8 years or more.Methods: Between 2003 and 2014, 293 patients were treated with unicondylar knee arthroplasty due to medial gonarthrosis, and 239 patients that we followed up for at least 18 months were included in the study. Nine of the patients (3.7%) underwent bilateral operation, 193 (77.8%) patients were operated with the fixed insert design, and 55 (22.2%) patients were operated with the mobile insert design. A total of 248 knees were evaluated retrospectively. 64±5.32 (68-78), and the mean Knee Society Knee Scoring System (KSS) score was 70.6±3.9 (66-89). The postoperative mean WOMAC value was 97.23±4.02 (92-100) (p<0.05), and the mean KSS score was 92.3±3.94 (85-100) (p<0.05). Results Conclusion:When we compared the fixed and mobile insert design prosthesis, there was no statistically significant difference between the knee scores, but the mobile insert design prosthesis had better flexion degrees. We have observed 97.2% prosthesis survival rates over 8 years. In conclusion, unicondylar knee prosthesis is a good treatment option, with a high success rate for medial knee osteoarthritis. (JAREM 2016; 6: 31-4)