Identifying Key Risk Factors in Elective 1 or 2 Level Lumbar Spine Fusion Patients: A Focus on Patients Classified High Medical Risk who are Cannabis Users.

Abstract

Retrospective case-control study. The goal of this study was to identify key risk factors that were associated with 90-day complication rates, and 12-month recovery metrics following an elective single or 2-level lumbar fusion. Preoperative screening for risk factors associated with poor outcomes is common in elective surgeries. Recent changes in legal status of cannabis has led to questions concerning the impact of cannabis use on postoperative recovery, complications, and pain management in patients undergoing elective lumbar fusions. This retrospective study included patients ages 35 to 80 who underwent elective single- or two-level lumbar fusions between January 2022 and May 2025. Patients were classified as either high-risk or normal risk during their preoperative optimization visit. Four groups were created based on risk classification and cannabis use: high-risk cannabis users (HR-C), high-risk non-users (HR), normal risk cannabis users (NR-C), and normal risk non-users (NR). Differences were compared using Chi-squared tests and ANOVAs. Regression analyses identified preoperative metrics associated with poor outcomes. A total of 575 patients (142 HR, 30 HR-C, 433 NR, 101 NR-C) were included. HR-C patients showed two-fold higher opioid use ( P <0.001), longer length of stay ( P <0.001), and higher incidents of surgical site infections compared to NR- patients ( P <0.01). Cannabis use was associated with increased SSI rates, while tobacco use and mental illness were associated with emergency department utilization and readmissions, and alcohol use and preoperative pain were associated with return to the OR. This study identifies specific risk factors in patients with poor outcomes. Cannabis use was associated with adverse spinal fusion outcomes and should be included as a preoperative screen, with others such as alcohol and tobacco use, and mental health. Screening can determine which patients may benefit from preoperative optimization and postoperative follow-up using patient-centered targeted interventions. III.