Unicompartmental knee arthroplasty: 10-year follow-up

Aim. This study presents the long to midterm results of a series of medial unicompartmental knee arthroplasty (UKA). Methods. A series of 69 primary UKA implanted consecutively in 67 patients were subjected to clinical and radiographic evaluation at a mean follow-up of 124.63 months, approximately 10 years (range from 60 to 251). There were 21 men (31.34%) and 46 women (68.66%) with an average age of 68.59 years (range 56 to 82 years). Patients were assessed using the Hospital Special Surgery Knee Score (HSS-KS) and the Knee Society Total Knee Arthroplasty Roentgenographic Evaluation and Scoring System. Results. Preoperatively, the mean knee score was 56.85 points (SD +/- 8.3) and post-operatively the mean knee score was 84.62 points (SD +/- 6.63). The survival rate, with the revision of the implant as end-point, was 96.7%, 84.1% and 80.2% at 5, 10 and 15 years, respectively. Nevertheless, 48% of the patients reported medium pain, the 20% moderate pain and the 12% severe pain, respectively. Conclusion. This study shows acceptable results with UKA, but lower survival compared to other series. UKA does not provide the same survival rate and level of clinical results as total knee arthroplasties. The postoperative axis is the only factor correlated to failure in selected patients.