UNICOMPARTMENTAL KNEE ARTHROPLASTY WITH KINEMATIC NAVIGATION: FOLLOW-UP 4 YEARS

Abstract

To evaluate short term results of 126 computer assisted unicompartmental knee arthroplasty (UKA) with ligament balancing.

Between September 2003 and November 2007 we performed 126 computer asssited surgery UKA Preservation. We using kinematic navigation Ci system. This is cemented system with mobile or fixed bearing. Our groups included 72 women and 54 men. Average age at surgery was 71,2 years. The indication for UKA include primary or postraumatic osteoarthritis limited to one compartment, a functional anterior cruciate ligament, no inflamatory disease. In all cases was only medial femorotibial osteoarthritis. Arthroscopic partial medial menisectomy was performed in 25 cases. Approach: medial parapatellar arthrotomy. Clinical evaluation was performed by Hospital for Special Surgery knee scoring system (HSS). Imaging: AP,lateral and stress X-rays.

The average HSS score was 57 point (range, 40–79 points) preoperatively and 94 points (range 62–100 points) postoperatively. 90% patients were classified as excellent or good using the HSS. The average range of motion before surgery: S 0-0-120 gr., 6 days after surgery S 0-0-110 gr. and 3 months after surgery S 0-0-125 gr.

No significant difference in maximum flexion was seen between the preoperative and postoperative values. There were no infection, fracture of tibia plateau, poor pain, or sign of patellar impingement.

UKA together with modern design, reproductible instrumentation and kinematic navigation can eliminate the previous cause of early failures, contralateral tibiofemorial degeneration and tibial loosening. The patient’s selection must be strict regarding (the ideal patient more than sixty years old, low Body Mass Index, low demand of physical activity). Kinematic navigation reduces the possibility of surgeon’s mistake, alignement of the femoral and tibial component, resection level, soft tissue balancing. It increases the accuracy of the comoponent position, especially in the side of the tibia. A continued long term follow-up is necessary to evaluate polyethylene wear after 10 years.