The Long-Term Results of Simultaneous High-Flexion Mobile-Bearing and Fixed-Bearing Total Knee Arthroplasties Performed in the Same Patients

Background: Our study determined the long-term clinical, radiographic, and computed tomography scanning results of high-flexion mobile-bearing and fixed-bearing total knee arthroplasties (TKAs) in the same younger patients. In addition, the survivorship and complication rates of both groups were evaluated. Methods: Bilateral simultaneous sequential TKAs were performed in 164 patients (328 knees). There were 142 women and 22 men with a mean age of 63 +/- 9 years (range 41-65), who received a high-flexion mobile-bearing prosthesis in one knee and a high-flexion fixed-bearing prosthesis in the other. The mean follow-up was 16.9 years (range 15-18). Results: At the latest follow-up, the mean Knee Society knee scores (94 +/- 8 vs 95 +/- 9 points, P = .7), Western Ontario and McMaster Universities Osteoarthritis Index (20 +/- 11 vs 20 +/- 11 points, P = 1.0), range of knee motion (125 degrees +/- 10 degrees vs 127 degrees +/- 9 degrees, P = .8), and University of California, Los Angeles activity scores (7.8 vs 7.8 points, P = 1.0) were below the level of clinical significance between the 2 groups. Survival rate of high-flexion mobile-bearing TKA was 98.2% and that of high-flexion fixed-bearing TKA was 97% at 16 years. No osteolysis was identified in either group. Conclusion: After a minimum duration of follow-up of 13 years, we found no significant difference between these 2 groups with regard to functional outcome, knee motion, prevalence of osteolysis, or survivorship. This study does not clearly direct the surgeon toward either arm of treatment. Longer term follow-up is needed to prove the superiority of one type of implant over the other one. (C) 2018 Elsevier Inc. All rights reserved.