Comparison of Clinical Outcomes for Patients Treated With Gradually Reducing Radius Versus Single-Radius Total Knee Arthroplasty Systems

The choice of implant used for primary total knee arthroplasty (TKA) may have an impact on clinical outcomes. Clinical outcomes after TKA with gradually reducing radius implants (group G) vs single-radius implants (group S) were evaluated among Asian patients. This study included 541 patients (754 knees) in group G and 187 patients (275 knees) in group S. Range of motion (ROM), flexion contracture, American Knee Society Knee and American Knee Society Function scores (KSKS and KSFS, respective-ly), and mechanical and anatomic tibiofemoral angles (MTFA and ATFA, respectively) were evaluated with electronic medical records. In univariate analysis, improvements in ROM, KSKS, and KSFS were significantly better in group G compared with group S at 1-year follow-up. Multivariable analy-ses showed greater ROM (4.52 & DEG;, P=.002), decreased flexion contracture (-2.80 & DEG;, P=.011), and improved KSKS (15.57, P <.001) at 1 year for group G vs group S. No significant differences in KSFS, MTFA, or ATFA were ob-served. Implant-related complications and radiologic loosening were not identified in either group at 2-year follow-up. The TKA implants with a grad-ually reducing radius showed greater 1-year improvements in ROM, flexion contracture, KSKS, and similar implant-related safety outcomes compared with a single-radius system.