Long-Term (Up to 27 Years) Prospective, Randomized Study of Mobile-Bearing and Fixed-Bearing Total Knee Arthroplasties in Patients <60 Years of Age With Osteoarthritis

Background: Our study determined long-term (up to 27 years) results of fixed-bearing vs mobile-bearing total knee arthroplasties (TKAs) in patients <60 years with osteoarthritis. Methods: This study included 291 patients (582 knees; mean age 58 ± 5 years), who received a mobile-bearing TKA in one knee and a fixed-bearing TKA in the other. The mean duration of follow-up was 26.3 y (range 24-27). Results: At the latest follow-up, the mean Knee Society knee scores (91 ± 9 vs 89 ± 11 points, P =.383), Western Ontario and McMaster Universities Osteoarthritis Index (35 ± 7 vs 37 ± 6 points, P =.165), range of knee motion (128° ± 13° vs 125° ± 15°, P =.898), and University of California, Los Angeles activity score (6 ± 4 vs 6 ± 4 points, P = 1.000) were below the level of clinical significance between the 2 groups. Revision of mobile-bearing and fixed-bearing TKA occurred in 16 (5.5%) and 20 knees (6.9%), respectively. The rate of survival at 27 years for mobile-bearing and fixed-bearing TKA was 94.5% (95% confidence interval 89-100) and 93.1% (95% confidence interval 88-98), respectively, and no significant differences were observed between the groups. Osteolysis was identified in 4 knees (1.4%) in each group. Conclusion: There were no significant differences in functional outcomes, rate of loosening, osteolysis, or survivorship between the 2 groups.