Cannabis Use is Associated With Higher Rates of Pseudarthrosis Following TLIF

Study Design.This was a retrospective cohort study. Objective.To compare the rates of pseudarthrosis in patients undergoing 1 to 3 level transforaminal lumbar interbody fusion (TLIF) procedures between cannabis users and noncannabis users. Summary of Background Data.Recreational use of cannabis is common, though it remains poorly studied and legally ambiguous in the United States. Patients with back pain may turn to adjunctive use of cannabis to manage their pain. However, the implications of cannabis use on the achievement of bony fusion are not well-characterized. Methods.Patients who underwent 1 to 3 level TLIF for degenerative disc disease or degenerative spondylolisthesis between 2010 and 2022 were identified using the PearlDiver Mariner all-claims insurance database. Cannabis users were identified with ICD 10 code F12.90. Patients undergoing surgery for nondegenerative pathologies such as tumors, trauma, or infection were excluded. 1:1 exact matching was performed using demographic factors, medical comorbidities, and surgical factors which were significantly associated with pseudarthrosis in a linear regression model. The primary outcome measure was development of pseudarthrosis within 24 months after 1 to 3 level TLIF. The secondary outcomes were the development of all-cause surgical complications as well as all-cause medical complications. Results.A 1:1 exact matching resulted in two equal groups of 1593 patients who did or did not use cannabis and underwent 1 to 3 level TLIF. Patients who used cannabis were 80% more likely to experience pseudarthrosis compared with patients who do not [relative risk (RR): 1.816, 95% CI: 1.291-2.556, P<0.001]. Similarly, cannabis use was associated with significantly higher rates of all-cause surgical complications (RR: 2.350, 95% CI: 1.399-3.947, P=0.001) and all-cause medical complications (RR: 1.934, 95% CI: 1.516-2.467, P<0.001). Conclusion.After 1:1 exact matching to control for confounding variables, the findings of this study suggest that cannabis use is associated with higher rates of pseudarthrosis, as well as higher rates of all-cause surgical and all-cause medical complications. Further studies are needed to corroborate our findings.