Discordance Between Hip-Specific PROMs and Lumbar Symptoms After Total Hip Arthroplasty in Patients With Prior Lumbar Fusion.

BACKGROUND: Hip-specific patient-reported outcome measures (PROMs) are used to assess patient recovery after total hip arthroplasty (THA), but their efficacy in patients with prior lumbar spinal fusion (LSF) remains less clear. This study evaluated the discordance between improvements in hip-specific PROMs and persistent lumbar-related symptoms in patients with prior LSF who underwent THA. METHODS: We performed a single-center retrospective study of patients with prior LSF who underwent THA from January 2015 to October 2025. Multiple PROMs, including PROMIS-10, HOOS Jr., University of California Los Angeles Activity Score, and EQ-5D, were analyzed using paired Wilcoxon signed-rank tests. Lumbar-related symptoms were assessed by structured chart review and treated as binary variables. RESULTS: Overall, 54 total cases from 47 unique patients were identified, including 41 total cases in the primary cohort. Paired baseline and 3-month PROMs were available for 18 total cases. Significant improvements occurred in HOOS Jr. (+27.66, P < .001), PROMIS pain (-3.06, P < .01), PROMIS physical (+6.06, P < .01), and EQ-5D overall health (+17.0, P = .012). However, despite these improvements in multiple PROMs, lumbar-related symptoms still persisted at baseline, 3 months, 6 months, 1 year, and 2 years in 20.0%, 14.3%, 13.3%, 33.3%, and 25.0% of patients, respectively. CONCLUSIONS: THA was associated with significant and meaningful early hip-specific functional improvements in patients with prior LSF. However, lumbar-related symptoms frequently persisted in many patients. This discordance suggests that hip-specific PROMs may incompletely capture postoperative recovery with hip-spine syndrome. However, these findings should be interpreted as exploratory and hypothesis-generating. LEVEL OF EVIDENCE: Level IV, Therapeutic study.