Effect of posterior condylar offset on clinical results after posterior-stabilized total knee arthroplasty

摘要

Purpose:To determine the effect of the posterior condylar offset (PCO) on clinical results after total knee arthroplasty (TKA) using a high-flex posterior-stabilized (PS) fixed-bearing prosthesis.Methods:We prospectively studied the clinical and radiographic materials of 89 consecutive female patients (89 knees),who had undergone primary TKAs for end-stage osteoarthritis.All operations were performed by a single senior surgeon or under his supervision using the same operative technique.Based on the corrected PCO change,we divided all cases into two groups:group A (corrected PCO change ≥0 mm,58 knees) and group B (corrected PCO change ＜0 mm,31 knees).One-year postoperatively,clinical and radiographic variables from the two groups were compared by independent t-test.The associations between the corrected PCO changes and the improvements of clinical variables in all patients were analyzed by Pearson linear correlation.Results:One-year postoperatively,the Knee Society Scores,the Western Ontario and McMaster Universities Osteoarthritis Index,non-weight-bearing active and passive range of knee flexion,flexion contracture,extensor lag,and their improvements had no statistical differences between the two groups (all p ＞ 0.05).The corrected PCO change was not significantly correlated with the improvement of any clinical variable (all p ＞ 0.05).Group A demonstrated greater flexion than group B during active weight bearing (p ＜ 0.05).Conclusions:Restoration of PCO plays an important role in the optimization of active knee flexion during weight-bearing conditions after posterior-stabilized TKA,while it has no benefit to non-weight-bearing knee flexion or any other clinical result.