Functional performance of mobile versus fixed bearing total knee prostheses: a randomised controlled trial

• Published in: Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA Vol. 20; no. 8; pp. 1450 - 1455
• Main Authors: Jacobs, W. C. H., Christen, B., Wymenga, A. B., Schuster, A., van der Schaaf, D. B., ten Ham, A., Wehrli, U.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.08.2012; Springer Nature B.V
• Subjects: Aged; Arthritis; Climbing; Female; Humans; Hypotheses; Joint replacement surgery; Kinematics; Knee; Knee Joint - physiopathology; Knee Joint - surgery; Knee Prosthesis; Knees; Male; Medicine; Medicine & Public Health; Middle Aged; Orthopedics; Osteoarthritis; Osteoarthritis, Knee - physiopathology; Osteoarthritis, Knee - surgery; Patients; Prostheses; Prosthesis Design; Range of motion; Range of Motion, Articular; Recovery of Function; scoring; Sports; Surgeons; Surgery; Transplants & implants; Treatment Outcome; Switzerland; Netherlands; Prostheses and implants; Knee arthroplasty; Osteoarthritis; Mobile bearing; Functional performance; Knee flexion
• ISSN: 0942-2056; 1433-7347
• DOI: 10.1007/s00167-011-1684-9

Purpose The primary goal of this study was to assess the difference in active flexion between patients with a mobile versus a fixed bearing, cruciate retaining, and total knee arthroplasty. The study was designed as a randomised controlled multi-centre trial. Methods Participants were assigned to interventions by using block-stratified, random allocation. Outcome parameters were active flexion, passive flexion, and Knee Society Score (KSS). Outcome parameters were assessed preoperatively and at 3, 6, and 12 months postoperatively by an independent nurse. Results Ninety-two patients from one centre were included, 46 in each group. Active flexion was comparable for the two groups, 99.9° for the mobile bearing group and 101° for the fixed bearing group with a baseline controlled difference of 1.0 (95% CI −3.9 to 5.8, n.s.). The Clinical KSS was comparable between the two bearing groups (Mobile 90.0 vs. fixed 92.4, n.s.). The functional KSS showed a difference that was attributable to the stair climbing subscore, which showed a difference in favour of the fixed bearing design between preoperative and 3 months (7.3 point difference; 95% CI 2.3–12.5; P  = 0.005) as well as 12 months (4.8 point difference; 95% CI 0.1–9.6; P  = 0.045). Conclusions There were no short-term differences in active flexion between fixed bearing and mobile bearing total knee arthroplasty. Level of evidence I.