Impact of Preoperative Marijuana Use on Functional Recovery and Complications After Spinopelvic Fusion in Adult Spinal Deformity

BACKGROUND AND OBJECTIVES: With the rising prevalence of marijuana use and increasing rates of complex spinal deformity surgeries, understanding the impact of cannabis on perioperative outcomes is crucial. Previous studies yield mixed results on fusion success, complications, and opioid use in spine surgery, but none have focused on long-segment spinopelvic fusions. METHODS: This retrospective cohort study analyzed 155 adult patients undergoing posterior spinal fusion from the pelvis to L2 or higher between 2015 and 2023. Patients were stratified by preoperative marijuana use (n = 34 users vs n = 121 nonusers). Baseline demographics, surgical parameters, clinical outcomes [Oswestry Disability Index (ODI), visual analog scale], radiographic measures (pelvic tilt, lumbar lordosis, and sagittal vertical axis), and complications were compared using t -tests, χ 2 tests, and logistic regression, with P < .05 considered significant. RESULTS: Marijuana users had higher preoperative opioid dependence (64.7% vs 42.9%, P = .025), more previous spine surgeries (52.9% vs 19.0%, P < .001), and elevated preoperative ODI scores (56.9 vs 52.8, P = .038), but demonstrated greater ODI improvement (43.7 vs 37.1, P = .003). No significant differences were observed in visual analog scale changes, radiographic corrections, hospital stay (8.8 vs 8.9 days, P = .920), transfusions (2.2 vs 1.5 units, P = .240), medical complications (eg, deep vein thrombosis/pulmonary embolism: 4 vs 21, P = .599), or mechanical complications (eg, pseudarthrosis: 10 vs 36, P > .999, and hardware failure: 12 vs 53, P = .434). CONCLUSION: In this cohort, preoperative marijuana use was not associated with statistically significant differences in complication rates or inferior outcomes after long-segment spinopelvic fusion. Users experienced enhanced functional recovery, although this finding must be interpreted in the context of their higher baseline disability. Given the modest sample size, these findings should be viewed as preliminary; prospective studies with standardized cannabis exposure metrics are needed to confirm these results.