Medium-term results of the AMC-unicompartmental knee arthroplasty

This study presents the outcome of patients treated by AMC-unicompartmental knee arthroplasty (UCA). The prosthesis was implanted in 361 cases for the medial or lateral compartment arthritis. The mean follow-up period was 5.5 (range: 2.3-12.5) years. Mean age at surgery was 69.5 (range: 46.3-88.6) years. Six knees were lost to follow-up (1.6%). Patients were assessed by an independent clinical observer and results were standardised using the Knee Society Rating System. The roentgenographic analyses were performed according to the Knee Society Evaluation System. Ninety-five percent of patients had no pain or slight pain at the latest follow-up, 92% had a good or excellent clinical outcome. Three knees were revised for mobile bearing dislocation after medial UCA and three for lateral mobile bearing dislocation after lateral UCA. Five revisions were necessitated by component loosening and there was one case of deep infection. The clinical results of the investigated patients demonstrate that the AMC-UCA is a successful concept with safe fixation of the prosthesis and good durability of the mobile bearings.