To evaluate the early postoperative results of Unicompartmental Knee Arthroplasty (UKA) based on a prospective analysis and follow up study.

Clinical assessments were carried out using the Knee Society Score (KSS) rating system. The tibiofemoral angle and radiographic changes were measured using weight-bearing X-rays. Prospective assessments were conducted preoperatively, and regularly followed up after the operation. Among the cases of UKA performed since January 2002, 67 were able to be followed up at 3, 6, 12 and 24 months after the operation.

For these 67 knees, the average preoperative knee score and the knee function score were 54.6 and 56.3 points, respectively. The knee score was improved to 80.1, 85.4, 86.8 and 89.2 points at 3, 6, 12 and 24 months follow ups, respectively. The knee function score was also improved to 70.4, 76.0, 80.2 and 83.0 points at 3, 6, 12 and 24 months. The average range of knee motion was 127.6 ° preoperatively, and recovered to 128.6 ° at 3 months postoperatively. The preoperative tibiofemoral angle was 0.7 ° of valgus, which changed to 5.7 ° of valgus at 24 months postoperatively.

As shown in this prospective study, the early postoperative results of UKA were satisfactory for improvement of knee score, function score and in the recovery of knee motion.