A New Prediction Model of Patient Satisfaction After Total Knee Arthroplasty and The Roles of Different Score Systems: A retrospective cohort study

Abstract BACKGROUNDAlthough total knee arthroplasty (TKA) is efficacious treatment for end-stage osteoarthritis, ~20% patients are dissatisfied with the results. We determined which factors contribute to patient satisfaction and compared the various scoring systems before and after surgery.METHODSIn this retrospective cohort study, 545 patients were enrolled and were evaluated preoperatively and 1 year postoperatively. Patient demographics, as well as scores for Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Short Form (SF)-12, and 1989 Knee Society Clinical Rating System (KSS) were recorded preoperatively and postoperatively. The possible predictors were introduced into a prediction model. Scores for overall satisfaction and 2011 Knee Society Score(KSS) were also assessed after total knee arthroplasty to identify the accuracy and agreement of the systems.RESULTSThere were 134 male patients and 411 female patients, with an overall prevalence of satisfaction of 83.7% 1 year after surgery. A history of surgery(p<0.001) , 1989 KSS and SF-12 were of the utmost importance in the prediction model, whereas the WOMAC score had a vital role postoperatively(change of WOMAC pain score, p<0.001; change of WOMAC physical function score, p<0.001; postoperative WOMAC pain score, p=0.004). The agreement between assessment of overall satisfaction and 2011 KSS satisfaction assessment was general(Kappa=0.437>0.4, p<0.001). CONCLUSIONA history of surgery, preoperative 1989 KSS and preoperative SF-12 influenced patient satisfaction after primary total knee arthroplasty. We recommend WOMAC (particularly the subscale score of pain) to reflect the overall patient satisfaction postoperatively.