Quantitative, Comparative Assessment of Gait Between Single-Radius and Multi-Radius Total Knee Arthroplasty Designs

Gait of single-radius (SR, n = 16) and multi-radius (MR, n = 16) posterior stabilized total knee arthroplasties was compared, along with controls (n = 16), pre-op and 1 year post-op. Computer navigation and standard order sets controlled confounding variables. Post-operatively, SR knees did not differ from controls while MR knees continued to differ in important knee kinetic and kinematic properties. MR knees remained more extended (P = 0.019) and had decreased power absorption (P = 0.0001) during weight acceptance compared to the SR knees. Both surgical groups had similar KSS for Knee Scores (P = 0.22) and Function Scores (P = 0.58). The significant biomechanical differences are likely influenced by patella–femoral moment arm geometry and changing ligament laxity throughout the active range of motion.