The Relationship between Western Ontario and McMaster Universities Osteoarthritis Index Score and Satisfaction after Total Knee Arthroplasty Changes Over Time

This study aimed to determine whether there was a relationship between preoperative patient-reported outcome measures (PROMs) and satisfaction after total knee arthroplasty (TKA), and whether there was a relationship between the amount of improvement in PROM or final PROM and satisfaction and whether that relationship differed 1 and 2 years after TKA. The Western Ontario and McMaster University Osteoarthritis Index (WOMAC) and satisfaction of 267 limbs who underwent TKA were analyzed. Logistic regression analysis was performed to determine whether there was a relationship between preoperative WOMAC or improvement in WOMAC or final WOMAC and satisfaction at 1 and 2 years after TKA. Pearson and Filon's z test was performed to determine whether there was a difference in evaluating satisfaction between the amount of improvement in WOMAC and final WOMAC. There was no significant relationship between preoperative WOMAC and satisfaction. A higher improvement in WOMAC total score and better final WOMAC total scores at 1 and 2 years after TKA were related to greater satisfaction. At 1 year after TKA, there was no significant difference in evaluating satisfaction between the amount of improvement in WOMAC and final WOMAC. However, 2 years after TKA, the final WOMAC function and total score were more related to satisfaction than the amount of improvement in WOMAC function and total score. In the early postoperative period, there was no difference in evaluating satisfaction between the amount of improvement in WOMAC and final WOMAC, whereas over time, the final WOMAC was more related to satisfaction.