Mobile-Bearing Versus Fixed-Bearing Total Knee Arthroplasty: Results With a Cruciate-Retaining Knee System

This retrospective study compared 2- to 5-year results of fixed-bearing (n = 115) and mobile-bearing (n = 147) total knee arthroplasty. Knee Society score (KSS), passive range of motion (ROM), functional ROM, and radiographs were reviewed. Fixed-bearing: (50 male, 65 female), averages: age, 63 (42-71); follow-up, 4 years (2-5); body mass index, 32 (26-39); postoperative KSS pain, 96 (85-100); function, 79 (60-100). Average PROM, 117° (90°-125°); average functional ROM, 98° (40°-120°). X-rays: 15 (13%) with incomplete radiolucent lines (11 nonprogressive, 4 progressive). Mobile-bearing: (80 female, 67 male), averages: age, 61 years (45-78); follow-up, 3.2 years (2-5); body mass index, 31 (23-38); postoperative KSS pain, 93 (86-100); function, 76 (70-100). Average PROM, 120° (85°-130°); functional ROM, 100° (50°-120°). X-rays: 18 (12.2%) radiolucencies, all nonprogressive. No revisions in either group. No significant difference in PROM (P = .076), functional ROM (P = .456), KSS (P = .581), or nonprogressive radiolucencies (P = .495). Fixed-bearing had a higher number of progressive radiolucencies (P = .023).