A Comparison of Mobile-bearing and Fixed-bearing Total Knee Arthroplasties in Osteoarthritic Patients

ABSTRACT

PURPOSE: To compare the early clinical and radiographic results including patient's satisfaction after total knee arth- roplasty(TKA) using a mobile bearing knee prosthesis with fixed-bearing device. MATERIALS AND METHODS: From February 2002 to March 2004, author performed 30 posterior cruciate-retaining mobile bearing TKA and 39 posterior cruciate-retaining fixed bearing TKA. Clinical results were evaluated with knee score, patient's satisfaction by WOMAC score and range of motion. Radiographic analysis including tibio-femoral angle was also done. RESULTS: 1) The average knee score improved from 41.9 to 88.6 in mobile bearing group and from 44.3 to 87.6 in fixed bearing group respectively. The improvement of functional score were similar that 49.7 in mobile bearing group, 50.2 in fixed bearing group. 2) The average WOMAC score improved from 85.2 to 12.5 in mobile bearing group and from 85.3 to 13.9 in fixed bearing group. 3) The average range of motion of knee improved from 106.2 to 120.5 in mobile bearing group and from 105.2 to 118.8 in fixed bearing group. 4) The average tibio-femoral angle improved from 5.0 varus to 5.7 valgus in mobile bearing group and from 5.6 varus to 5.7 valgus in fixed bearing group. 5) Two of mobile and one of fixed bearing group complained persistent knee pain and two of mobile and one of fixed bearing group complained giving way sensation. CONCLUSION: This study shows that no significant difference in ROM, function, subjective evaluation and radiologic analysis for patients between two groups after minimum two-year follow-up.