Matched study finds no early outcome differences after scoliosis fusion

STUDY DESIGN: This was a retrospective matched-cohort study. OBJECTIVE: There is limited information about the effects of cannabis on patients undergoing surgery for adolescent idiopathic scoliosis (AIS). This study investigated if self-reported cannabis use is associated with postoperative pain, opioid use, and complication rate after spinal fusion. METHODS: AIS patients with self-reported preoperative cannabis use were matched to control subjects with no history of cannabis use. Matching criteria included age at surgery, sex, initial curve magnitude, curve type, and number of levels fused. Inclusion required an AIS diagnosis and spinal fusion at a single center from 2011 to 2019. Intraoperative outcomes, pain scores, medication use, and postoperative complications were collected. Follow-up duration was 1 month. RESULTS: Thirteen cannabis positive patients with AIS were matched to 65 controls (median age 18.1, 65% males). A significant increase was observed in surgical time per level fused for cannabis patients (33 vs 28 min, P = 0.03), but this was insignificant when controlling for the propensity score (P = 0.08). No significant differences were observed in intraoperative outcomes, pain scores, pain medication use, discharge pain medication amounts, length-of-stay, curve correction, or complication rate. CONCLUSION: Preoperative cannabis use was not associated with differences in surgical safety, anesthesia risk, inpatient pain, opioid use, and postoperative complications to the interval of the first postoperative appointment. Future prospective research is needed to determine the effects of cannabis on long-term follow-up from AIS spinal fusion.