Total knee replacement and health‐related quality of life: Factors influencing long‐term outcomes

OBJECTIVE: To evaluate health-related quality of life (HRQOL) in patients with osteoarthritis undergoing total knee replacement (TKR); identify the influence of sociodemographic, clinical, intraoperative, and postoperative variables on HRQOL; and determine patient perceptions at 7 years. METHODS: We conducted a prospective study with 7 years of followup. HRQOL measures (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC] and Short Form 36 [SF-36]); sociodemographic, clinical, intraoperative, inpatient, and postoperative data; patient perceptions of TKR outcomes; and physical activity at 7 years were determined. Associations were analyzed using linear regression models. RESULTS: Of 146 eligible patients, 112 (86 women, mean age 67.3 years) completed followup data. There were significant differences between pre- and postoperative WOMAC pain, stiffness, and function scores (P < 0.001). Variables retained in each of the models explained 14-32% (adjusted R(2)) of variability of the WOMAC dimensions. Obesity and postdischarge complications were associated with worse scores in all WOMAC dimensions (P < 0.05). Eighty-six percent of patients were satisfied with TKR, 80% would undergo the operation again, and 56% did regular physical activity and had better WOMAC scores (P < 0.05, except for stiffness [not significant]). Mean +/- SD SF-36 scores for men and women at 7 years were 55.1 +/- 27.1 and 39.5 +/- 22.9 for physical function, 71.2 +/- 36.5 and 51.5 +/- 42.7 for physical role, 66.2 +/- 26 and 55.6 +/- 28.9 for bodily pain, and 60.7 +/- 17.1 and 50.7 +/- 21.2 for general health, respectively. CONCLUSION: WOMAC dimension scores, especially pain, significantly improved at 7 years and were negatively influenced by obesity and postdischarge complications. HRQOL measures may help identify an increased risk of negative outcomes after TKR.