Gender difference in outcome after total knee replacement.

PURPOSE: To compare the outcome after primary total knee replacement (TKR) for end-stage knee osteoarthritis (OA) in men versus women. METHODS: Records of 214 men and 1040 women who underwent primary TKR for end-stage knee OA and were followed up for a minimum of 2 years were reviewed. Knee flexion, Oxford Knee Score, Knee Society Score (KSS), and 8 subscores of Short Form 36 (SF-36) were recorded preoperatively and at postoperative 6 months and 2 years. RESULTS: Men and women were comparable only in age (67.9 vs. 67.3 years, p=0.244); men had a lower mean body mass index (27.0 vs. 28.3 kg/m(2), p<0.001). Preoperatively, men had better knee flexion (117º vs. 114.8º, p=0.05), Oxford Knee Score (33.5 vs. 36.8, p<0.001), KSS knee score (44.3 vs. 40.3, p=0.001), KSS function score (52.5 vs. 47.1, p<0.001), and all 8 subscores of SF-36 (p=0.005 to p<0.001). Compared with men, women achieved greater improvement at 6 months in Oxford Knee score (13.2 vs. 15.1, p=0.009) and KSS knee score (36.9 vs. 41.6, p=0.016), and at 2 years in Oxford Knee Score (15.0 vs. 17.9, p<0.001), KSS knee score (39.8 vs. 43.9, p=0.009), and SF-36 subscores of social functioning (23.6 vs. 35.1, p<0.001) and mental health (3.9 vs. 8.2, p=0.003). CONCLUSION: Compared with men, women had poorer preoperative knee flexion, Oxford Knee Score, KSS, and 8 subscores of SF-36, but achieved greater improvement in the Oxford Knee Score and KSS knee score at 6 months and 2 years, as well as in SF-36 subscores of social functioning and mental health at 2 years.