Preoperative Hip Disability and Osteoarthritis Outcome Score for Joint Replacement Scores Predict Timing and Achievement of Substantial Clinical Benefit Following Primary Total Hip Arthroplasty.

Abstract

Given the recent shift towards use of substantial clinical benefit (SCB) as a measure of success following primary total hip arthroplasty (THA), an understanding of the timing and rate of SCB achievement is necessary. The purpose of this study was to determine the timing and rate of SCB achievement within the first year following primary THA and to determine what patient- and surgery-level factors may influence the timing and likelihood of SCB achievement at one year following primary THA. We identified 3,307 primary THAs performed in 2,939 patients from August 1, 2015, to July 21, 2023, at a single tertiary care academic institution. Hip Disability and Osteoarthritis Outcome Score for Joint Replacement (HOOS JR) scores were collected preoperatively and at two weeks, three months, six months, and one year postoperatively. The mean age at surgery was 64 years, the mean BMI was 29, and 53% were women. The SCB was defined as an increase of at least 22 points in HOOS JR, following primary THA. The median time to SCB achievement was 80 days. Multivariate linear regression analyses demonstrated that lower preoperative HOOS JR scores were associated with a faster time to SCB achievement (P < 0.01). The overall one-year rate of SCB achievement was 83%. Multivariate logistic regression analyses demonstrated that higher preoperative HOOS JR scores (odds ratio (OR) 1.06, 95% confidence interval (CI) 1.04 to 1.07; P < 0.01) and a higher CCI score (OR 1.03, 95% CI 1.01 to 1.06; P = 0.03) were associated with a failure to achieve SCB at one year postoperatively. Preoperative HOOS JR scores influence the timing and likelihood of achievement of SCB at one year following primary THA. Surgeons should remain cognizant of these findings when counseling patients regarding early clinical outcomes following primary THA.