Preoperative Contralateral Joint And/Or Back Pain Impact on Achieving the Substantial Clinical Benefit for Hip Disability and Osteoarthritis Outcome Score-Joint Replacement.

BACKGROUND: The Centers for Medicare & Medicaid Services recently mandated reporting of patient-reported outcome measures following primary total hip arthroplasty (THA), with emphasis on the substantial clinical benefit (SCB) threshold for the Hip Disability and Osteoarthritis Outcome Score-Joint Replacement (HOOS-JR). The impact of preoperative back and/or contralateral hip pain on achieving SCB and other validated patient-reported outcome measure thresholds remains unclear.

METHODS: We retrospectively analyzed a prospective cohort of 4,412 Medicare primary elective unilateral THAs (2016 to 2023). Patients were stratified by preoperative back and/or contralateral hip pain and severity. Outcomes included achievement of SCB (22-point improvement in HOOS-JR), minimal clinically important difference, patient-acceptable symptom state, and satisfaction at one year. Multivariable logistic regression was adjusted for demographic, clinical, and socioeconomic factors.

RESULTS: Patients who had both back and contralateral hip pain had the highest odds of failing to achieve SCB (odds ratio (OR) 3.1, 95% confidence interval (CI) 2.4 to 4.1; P < 0.001), followed by isolated contralateral hip pain (OR 1.7, 95% CI 1.1 to 2.6; P = 0.01) and isolated back pain (OR 1.6, 95% CI 1.2 to 2.0; P = 0.002). Risk increased proportionally with pain severity (mild/moderate back pain: OR 1.7; severe back pain: OR 2.8; both P < 0.001). Similar, though less pronounced, patterns were observed for minimal clinically important difference and patient-acceptable symptom state thresholds across HOOS domains. Patients who have both pain sources also reported the highest risk of dissatisfaction (OR 2.1, 95% CI 1.5 to 3.0; P < 0.001).

CONCLUSIONS: Preoperative back and contralateral hip pain, particularly when severe or concurrent, strongly and independently reduce the likelihood of achieving SCB for HOOS-JR following primary THA. These findings underscore the need for risk adjustment under the Centers for Medicare & Medicaid Services patient-reported outcome performance measure framework and highlight the value of multidisciplinary management of comorbid pain to optimize outcomes and ensure equitable benchmarking in value-based care.

LEVEL OF EVIDENCE: II (Prospective).