Osteolysis in well-functioning fixed- and mobile-bearing TKAs in younger patients

Abstract

Background: Periprosthetic osteolysis is an increasingly prevalent complication of TKA. To reduce the polyethylene wear and periprosthetic osteolysis, particularly in young patients, the design of the contemporary fixed-bearing TKAs has been modified and mobile-bearing TKAs have been introduced. Questions/purposes: We asked whether the prevalence of osteolysis would be less in well-functioning mobile-bearing TKAs than in well-functioning contemporary fixed-bearing TKAs in young patients. Patients and Methods: We compared 488 patients (894 knees) who received fixed-bearing knee prostheses with 445 patients (816 knees) who received mobile-bearing knee prostheses. There were 187 men and 301 women (mean age, 58.6 years; range, 33-65 years) in the fixed-bearing group and 167 men and 278 women (mean age, 55.7 years; range, 33-65 years) in the mobile-bearing group. The mean followup was 12.6 years (range, 10-17 years) in the fixed-bearing group and 12.9 years (range, 10-17 years) in the mobile-bearing group. Results: The incidence of osteolysis was 1.6% (14 of 894 knees) in the fixed-bearing group and 2.2% (18 of 816 knees) in the mobile-bearing group at the final review. The mean postoperative Knee Society knee and function scores were 92.9 points and 83.5 points, respectively, in the fixed-bearing group and 90.7 points and 83.8 points, respectively, in the mobile-bearing group. The revision rates were 3.7% (33 of 894 knees) in the fixed-bearing group and 2.7% (22 of 816 knees) in the mobile-bearing group. Conclusions: We found the incidence of osteolysis, rate of revision, and implant survivorship were similar between fixed-bearing and mobile-bearing TKAs in younger patients. © 2010 The Association of Bone and Joint Surgeons®.