Unicondylar knee arthroplasty. 2-10 years of follow-up evaluation.

One hundred fifty-nine Mod II unicompartmental knee arthroplasties were reviewed. The follow-up period ranged from 2 to 10 years (average, 4 years and 6 months). Osteoarthritis was the most common reason for arthroplasty (108 cases). The patients' age at the time of operation averaged 72 years (range, 28-92 years). The diagnosis directly influenced the quality of the final results, which were assessed according to pain, range of motion, stability, and function. Patients with osteoarthritis and medial condyle osteonecrosis had the best results. The average flexion angle obtained was 115 degrees, and the average residual axial deviation was 6 degrees for varus deformities and 8 degrees for valgus deformities. Nine failures, including two deep infections, four femorotibial subluxations, two cases of deterioration of the opposite compartment, and one loosening, required eight revision procedures. Knee instability due to bony loss, much more frequent in osteoarthritis than pure ligamentous laxity, was regularly corrected with this procedure.