Unicompartmental arthroplasty: a long-term follow-up study.

Seventy-three consecutive unicompartmental knee arthroplasties (UKAs) using a Marmor-style non-metal-backed cemented tibial component were performed from 1975 to 1990. Sixty-seven knees (58 patients) were evaluated with minimum 5-year follow-up (mean, 9.7 years; range, 5-20 years). Knee rating and patient function were assessed using the updated Knee Society scoring system. Survivorship was 91% at 5 years, 84% at 10 years, and 79% at 15 years. The mean knee rating for surviving implants was 91 (range, 48-100), and mean functional score was 77 (range, 5-100). Survivorship and functional outcome were not affected by body habitus, age, gender, or tibial component thickness. UKA offers long-term relief of symptoms and excellent knee function in a high percentage of carefully selected patients with single compartment gonarthrosis.