Unicondylar Knee Arthroplasty Using Minimally Invasive Surgical Technique

ABSTRACT

PURPOSE: To evaluate the results of unicondylar knee arthroplasties using minimally invasive surgical(MIS) technique. MATERIALS AND METHODS: During the years 2000 and 2001, 195 unicondylar knee arthroplasties were completed by senior author with the Miller-Galante prosthesis(Zimmer, Warsaw, IN, USA). We analyzed clinical results, flexion/extension gap laxity and the radiological findings. RESULTS: The average preoperative range of motion(ROM) was 122 degrees. At the first follow-up appointment after the surgery, the average ROM was 111 degrees and it was improved to 130.1 degrees at 1-year follow up. The preoperative hospital for special surgery score was 53.8 and it was improved 92.4 postoperatively. The average extension gap for all of the surgeries was 1.47 mm and the flexion gap was 1.82 mm. The average correction of overall alignment on the follow-up x-rays was 3.9 degrees for the varus knees. The x-rays showed an increase of distal femoral valgus angle(1.79 degrees ) with 6 mm cut than with the 8mm cut(0.37 degrees ). The average proximal tibial varus angle was decreased from 5.45 degrees to 2.11 degrees and the average posterior slope of proximal tibia was decreased from 7.2 degrees to 4.5 degrees . CONCLUSION: Unicondylar knee arthroplasty by MIS technique guarantees early recovery and satisfactory radiological results. Therefore, long term follow-up evaluation is necessary.