The Desired Oxford Knee Score Obtained Before Total Knee Arthroplasty is Predictive of the Postoperative Oxford Knee Score: A Prospective Study

Background: The relationship between patient expectations and patient-reported outcome measures (PROMs) after total knee arthroplasty (TKA) is not well understood. The purpose of the study was to test the influence of desired knee function on postoperative perceived knee function 1 year after TKA. Methods: A total of 102 patients undergoing primary TKA were available for data analyses. Preopera-tively, patients completed the Oxford Knee Score (OKS) twice, one representing preoperative function (preoperative OKS); the second representing desired function after TKA (desired OKS). Western Ontario and McMaster Universities Arthritis Index (WOMAC), University of California, Los Angeles (UCLA) Activity score, Hospital for Special Surgery Knee Replacement Expectations Survey (HSS-KRES), Patient Health Questionnaire-9, and EuroQol-visual analogue scales were obtained preoperatively. One year after surgery, all surveys besides the UCLA activity score and HSS-KRES were repeated. The associations be-tween postoperative OKS and WOMAC versus desired OKS and HSS-KRES were assessed using multi -variable linear regression models, wherein linear regression coefficients represent the additive effect on the mean postoperative PROM. Results: The desired OKS was independently associated with the postoperative OKS (linear regression coefficient = 0.43; P = .011), that is, each point increase in desired OKS yielded a 0.43 increase in postoperative OKS. The preoperative OKS showed no association with postoperative PROMs. Desired OKS was correlated with postoperative WOMAC (coefficient =-0.67; P = .014). The HSS-KRES was not associated with the postoperative OKS (coefficient =-0.005; P = .965) or WOMAC (coefficient = 0.18; P = .288). Conclusion: In TKA patients, higher preoperative desired function predict greater postoperative PROMs. Effects of preoperative expectations on outcomes are independent of patient demographics or preop-erative function. (c) 2022 Elsevier Inc. All rights reserved.

Automated summary

This study aimed to examine the influence of desired knee function on postoperative perceived knee function 1 year after total knee arthroplasty (TKA). The results showed that higher preoperative desired function predicted greater postoperative patient-reported outcome measures (PROMs), while preoperative knee function was not associated with postoperative PROMs.