Effect of Rotation of Femoral Component on Subjective Scores of the KSS after TKA

Abstract：Objective To investigate the effect of rotational alignment of the femoral component on evaluation of outcomes using The 2011 KSS. Methods 158 patients with 198 knees(54 males with 68 knees,104 females with 130 knees)of primary posterior cruciate ligament-substituting(PS)TKA were follow-up five years postoperatively. The rotational alignment of the fem-oral components was assessed with computed tomography(CT)using the condylar twist angle(CTA),and the subjective scores of the KSS(2011)was evaluated. The patients were classified into three groups based on the rotational alignments of the femo-ral Component:Group A(external rotation of 3°to internal rotation of 3°),Group B(external rotation > 3°),Group C(internal rotation > 3°). scores of each category of The 2011 KSS were compared among the groups by statistical analysis. Results There was significant difference among groups in the category of functional activities,but no significant differences in the cate-gory of satisfactions and expectations. For each detail of the scores of functional activities,it showed significant differences a-mong groups in the category of standard activities,advanced activities and discretionary knee activities,but showed no signifi-cant difference in the categories of walking and standing. Conclusion The internal rotation of the femoral component affects the subjective score of functional activities,Surgeons should avoid malrotation of the femoral component.