Medial Unicompartmental Knee Arthroplasty in Chinese Population: Mid-term follow-up Results

Abstract

Background: Mismatch between the component and resected bone surface can result in poor clinical outcomes after unicompartmental knee arthroplasty (UKA). Although many studies have reported that UKA is a suitable procedure with reliable results in Caucasians, few studies have reported the clinical outcomes in Asians. This study reports our experience of the use of imported knee prostheses in a Chinese population. Methods: Forty-five patients with medial compartmental osteoarthritis who had undergone UKA 6 to 10 years previously were retrospectively followed up. All of the cases received Zimmer high flex system UKA. Pain score of Knee Society Score (KSS), KSS functional score and anatomic tibiofemoral angle, was recorded pre-operatively and post-operatively. The satisfaction rate and radiolucent line beneath the tibial component were also recorded at last follow-up. Results: The average KSS pain score was 13.7 pre-operatively and 43.4 post-operatively. The average KSS functional score was 45.7 pre-operatively and 78.3 post-operatively. The average anatomic tibiofemoral angle was 0° pre-operatively, 3° immediately postoperatively, and 4.6° at last follow-up. Radiolucent lines beneath the tibial component were observed in 40% of the cases and not correlated with poor functional outcomes or pain scores. Only one patient felt unsatisfied with the surgery. Conclusions: The patients who received UKA had good pain relief and acceptable functional performance in this study. The imported knee prostheses provided satisfactory results in this Chinese population, however not as good as those reported in Caucasians. Strict patient selection and good knee alignment are the crucial factors for UKA.