A Comparison Outcome Of Fixed-Bearing And Mobile-Bearing Prostheses In Primary Total Knee Arthroplasty At Mid-and Early-Follow-up

Objective:The purpose of this retrospective, randomized study was to compare the outcome of primary total knee arthroplasty by using a mobile-bearing (MB) and a fixed-bearing (FB) prosthesis.Methods:Between January2004and December2010,59patients(68knees), whose diagnose as osteoarthritis or rheumatoid arthritis or traumatic arthritis, were underwent total knee arthroplasty by using mobile-bearing or fixed-bearing knee prostheses. They were randomized be setting into MB group and FB group. The mobile-bearing total knee prosthesis was P.F.C Sigma RP(DePuy) and the fixed-bearing total knee prosthesis was NexGen Complete Knee Solution(Zimmer).30patients(34knees),26female and4male, used mobile-bearing prosthesis, and the average age of the patients was63.4years (range,49-73years).29patients (34knees),26female and3male, used mobile-bearing prosthesis, and the average age of the patients was65.1years (range,40-80years).During operative, all components were cemented, all patellas were non-displacement, and all cruciate ligaments were sacrificed. Clinical and radiographic follow-up was done by using Knee Society knee rating systems inpreoperative and postoperative.Results:All patients were follow up at a mean of53.2months (range,15-97months). The mean of age, BMI, Pain Score,ROM, Knee Score, Function Score were comparable in Preoperative. Inpostoperative, there were2patients (2knees) complication of knees infection and1penitents (1knees) complication of pulmonary embolism. No knee had aseptic loosening or osteolysis in either group. At the last follow-up, The mean of Pain Score, ROM, Knee Score, Function Score between MB group and FB group were similar(p<0.05), but they were different between preoperative and postoperative(p>0.05) in each group. Radiographic evaluation at the last follow-up showed stable fixation of all components, no gross migration and significant osteolysis that requiring bearing exchange.Conclusion:Both prosthesis could release painful and restore function of the knee, there is no clinically significant difference in the mid-and early-functional outcome between mobile-baring and fixed-bearing total knee arthroplasties. Further observations are expected to demonstrate the long-term clinical outcome.