Preoperative Factors Associated With Achieving Patient Acceptable Symptom State After Robot-Assisted Total Hip Arthroplasty Differ According to the Outcome Measure Used.

Abstract

Despite excellent overall satisfaction, patients undergoing total hip arthroplasty (THA) do not always achieve the expected outcomes, even with optimized implant positioning using robotic assistance. We hypothesized that preoperative factors associated with achieving patient-acceptable symptom state (PASS) would differ across patient-reported outcome measures (PROMs), reflecting distinct dimensions of postoperative recovery. This study aimed to identify preoperative factors associated with achieving the PASS after robot-assisted THA, according to different functional outcome scores. This was a single-center retrospective study based on a prospective cohort of patients who underwent robot-assisted total hip arthroplasty between 2018 and 2021. The following four outcome measures were analyzed: the Numeric Rating Scale (NRS) for pain, the Oxford Hip Score (OHS), the Harris Hip Score (HHS), and the Forgotten Joint Score (FJS). Included patients completed these outcome measures preoperatively and at 12 months postoperatively. A total of 368 patients were included in the study. The primary objective was to identify factors associated with achieving PASS for each outcome measure. Multivariable analyses were performed. Independent predictors of PASS varied according to the PROM used. Spino-pelvic mismatch (pelvic incidence-lumbar lordosis greater than -10°), absence of low back pain, and Tönnis grade 3 were associated with achieving PASS across all outcome measures. A preoperative Numeric Rating Scale for pain less than 7, sex (men), and age ≥ 55 years were significant predictors for three of the four outcome measures. A non-smoking status was associated with a PASS for the Numeric Rating Scale and Harris Hip Score, while higher socioeconomic status was associated with improved outcomes for selected patient-reported outcome measures. These findings confirm that each outcome measure captures distinct dimensions of functional outcome. Predictive factors of functional satisfaction after robot-assisted THA vary depending on the outcome measure evaluated. These findings suggest that a multifactorial and personalized assessment may help optimize patient expectations and functional outcomes.