A1175. EARLY CLINICAL OUTCOMES OF MODULAR BICOMPARTMENTAL ARTHROPLASTY

Abstract

Bicompartmental arthritis involving the medial and patellofemoral compartments of the knee is a common pattern that has often been treated with total knee arthroplasty.

However, the success of unicompartmental and patellofemoral arthroplasty for unicompartmental arthritis, as well as an interest in bone and ligament conservation for earlier stages of arthritis, has led to an interest in bicompartmental arthroplasty. The purpose of this study is to review the clinical, functional, and radiographic results of modular bicompartmental arthroplasty.

Twelve consecutive modular bicompartmental arthroplasties, using separate contemporary unicompartmental tibiofemoral and patellofemoral prostheses, were performed by the senior author. Clinical and functional data including range of motion (ROM), WOMAC and Knee Society (KS) scores were collected pre-operatively and post-operatively at 6 weeks, 12 weeks and annually. Radiographs were taken preoperatively and at the 6 week and annual postoperative visits. The average patient age at the time of surgery was 63 (range, 47 to 72); seven patients were women.

At most recent follow-up, the mean knee ROM improved from 100 degrees of flexion pre-operatively (range, 90 to 110) to a mean of 126 degrees of flexion (range, 115 to 130) (p < 0.0001). Improvements in WOMAC scores were statistically significant (p = 0.02). Statistically significant improvements in Knee Society scores were also observed (p = 0.03). No radiographs showed evidence of loosening, polyethylene wear or progressive lateral compartment degenerative arthritis. There were no complications in the peri-operative period.

Modular bicompartmental arthroplasty is an effective method for treating arthritis of the knee restricted to the medial and patellofemoral compartments. Early results using contemporary prostheses are encouraging and should prompt further mid-and long-term study.