Preliminary remarks on a prospective multicenter study of the Repicci minimally invasive unicondylar knee replacement

Prospective multicentric study on unicondylar knee arthroplasties using the minimally invasive method described by Repicci. Three hundred and seventy nine unicondylar knee arthroplasties in patients with an average age of 66 years were examined preoperatively and 40 weeks postoperatively. In 98.4% of the cases the medial compartment was replaced. The examination was documented using the Knee Society Score (KSS). Radiological examination was done using films of the knee in two planes in standing position and a long leg axis film. The mean KSS increased significantly (P<0.005) from 100.1 (SD 21.7) before surgery to 179.1 (SD 24.0) postoperatively. Ninety-five of the patients were subjectively satisfied with the procedure. Using correlation analysis, we found that osteoarthritic changes of the patella had a highly significant (p=0.001) influence on the KSS results. Patient's age and the pain subscale of the KSS also had a highly significant (p=0.01) influence on the KSS result. Short-term results of the Repicci unicondylar arthroplasty using the minimally invasive technique are encouraging in terms of patient satisfaction. It became apparent that osteoarthritic changes of the patella, flexion contractures and extension deficits have a considerable influence on the overall result.