Mid-Term Results for Unicompartmental Knee Arthroplasty

PURPOSE OF THE STUDY The purpose of this study was to evaluate clinical and functional results for a series of patients undergoing unicompartmental knee arthroplasty (UKA) at mid-term follow-up. MATERIAL AND METHODS This study included 32 patients with isolated medial compartment arthritis who underwent unilateral UKA. Outcomes were assessed using pre- and postoperative Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) scores and Knee Society Score (KSS) metrics. RESULTS On physical examination at a follow-up of at least 5 years, mean knee flexion was 121 degrees, mean knee extension was 2 degrees, and mean varus angulation was 2 degrees. At post-operative evaluation, the mean WOMAC score was 96.12 and the mean KSS score was 93. Pre- and postoperative WOMAC and KSS scores were evaluated by paired Student's t-tests; p < 0.001 determined a highly significant difference. DISCUSSION Early UKA designs had poor outcomes. Newer implant designs and specific patient selection criteria have been reported to be associated with improved outcomes. This study examined mid-term outcomes (mean duration of follow-up, 5 years). CONCLUSION The clinical and functional results of UKA at 5-year follow-up were shown to be satisfactory. Longer follow-up is needed to determine whether UKA provides satisfactory long-term outcomes.