Spine Surgery First Is Associated with Greater 1-year HOOS Improvement in Patients with Hip-spine Syndrome

Study Design. Retrospective Cohort Study Objective. This study aimed to: (1) compare demographic differences between spine-first and hip-first patients; (2) identify differences in perioperative outcomes; (3) determine whether surgical sequencing between hip and spine surgery influences patient reported outcomes (PROMS). Summary of Background Data. Hip-spine syndrome refers to coexisting lumbar degenerative stenosis and hip osteoarthritis. Surgical counseling remains challenging due to the symptomatic overlap between hip and spine disease, and there is no clear consensus on which disease should be addressed first. Methods. A retrospective review of a tertiary care center was performed (2002-2025). Patients were included if they had undergone a lumbar spinal fusion and a total hip arthroplasty in any sequence with an available 12-month Hip Disability and Osteoarthritis Outcome Score (HOOS). Patients were excluded if they had a history of spine revision surgery prior to hip surgery or hip revision surgery prior to spine surgery. HOOS scores were the primary outcome. Descriptive statistics were performed, and bivariate comparisons were made as appropriate. Multivariable analysis was performed to identify predictors of 1-year improvement in HOOS scores. Results. 179 patients (116 Spine-first, 63 Hip-first) were included. Overall, there were no significant demographic differences between groups. A greater number of patients with severe hip osteoarthritis underwent spine surgery first rather than hip surgery (66 vs. 18, P= 0.006). There were no significant differences regarding hip and spine revision surgeries between both groups. Spine-first patients underwent their second surgery in less time compared to hip-first patients (2.24 y vs. 4.03 y, P< 0.001). Furthermore, spine-first patients were more likely to have their second surgery within 1-year (45.7% vs. 11.1%), P< 0.001). Regarding PROMS, spine-first patients reported better 1-year improvement in HOOS scores (37.6 vs. 30.2, P= 0.045). Multivariable analysis revealed that undergoing spine surgery first was an independent predictor of 1-year HOOS improvement (β: 8.04 [0.47-15.60], P= 0.039). Conclusion. In this retrospective cohort, undergoing spine surgery first was associated with a modest 1-year HOOS improvement in hip-spine syndrome patients. It is important to note that these findings cannot speak towards causality, and further work is needed to validate these findings in prospective settings.