No Increased Risk of All-cause Revision up to 10 Years in Patients Who Underwent Bariatric Surgery Before Single-level Lumbar Fusion.

Study design: Retrospective cohort study.

Objective: This study aimed to assess whether prior bariatric surgery (BS) is associated with higher 10-year surgical complication and revision rates in lumbar spine fusion compared with the general population and morbidly obese patients.

Background: Obesity accelerates degenerative spine processes, often necessitating lumbar fusion for functional improvement. BS is explored for weight loss in lumbar spine cases, but its impact on fusion outcomes remains unclear. Existing literature on BS before lumbar fusion yields conflicting results, with a limited investigation into long-term spine complications.

Methods: Utilizing the PearlDiver database, we examined patients undergoing elective primary single-level lumbar fusion, categorizing them by prior BS. Propensity score matching created cohorts from (1) the general population without BS history and (2) morbidly obese patients without BS history. Using Kaplan-Meier and Cox proportional hazard modeling, we compared 10-year cumulative incidence rates and hazard ratios (HRs) for all-cause revision and specific revision indications.

Results: Patients who underwent BS exhibited a higher cumulative incidence and risk of decompressive laminectomy and irrigation & debridement (I&D) within 10 years postlumbar fusion compared with matched controls from the general population [decompressive laminectomy: HR = 1.32; I&D: HR = 1.35]. Compared with matched controls from a morbidly obese population, patients who underwent BS were associated with lower rates of adjacent segment disease (HR = 0.31) and I&D (HR = 0.64). However, the risk of all-cause revision within 10 years did not increase for patients who underwent BS compared with matched or unmatched controls from the general population or morbidly obese patients (P > 0.05).

Conclusions: Prior BS did not elevate the 10-year all-cause revision risk in lumbar fusion compared with the general population or morbidly obese patients. However, patients who underwent BS were associated with a lower 10-year risk of I&D when compared with morbidly obese patients without BS. Our study indicates comparable long-term surgical complication rates between patients who underwent BS and these control groups, with an associated reduction in risk of infectious complications when compared with morbidly obese patients. Although BS may address medical comorbidities, its impact on long-term lumbar fusion revision outcomes is limited.