While there is limited literature examining the potential connection, a team of orthopedic specialists sought further answers. They ultimately found that patients with a history of cannabis use are indeed less likely than non-users to experience adverse medical outcomes after thoracolumbar (lower back) spinal fusion (TLF) surgery. The study, “The Impact of Isolated Baseline Cannabis Use on Outcomes Following Thoracolumbar Spinal Fusion: A Propensity Score-Matched Analysis” was recently published in The Iowa Orthopedic Journal.
The orthopedic specialists, affiliated with the State University of New York (SUNY) Downstate Health Sciences University in Brooklyn, analyzed the relationship between cannabis use and surgical outcomes with a 704-patient cohort, all undergoing TLF surgery for adult spinal deformity (ASD). Researchers queried the New York Statewide Planning and Research Cooperative System database between January 2009 and September 2013 to identify all patients who underwent TLF for ASD. To be included, individuals were over the age of 18 and had either minimum 90-day or two-year follow-up surveillance.
According to the researchers, ASD is a spectrum of disorders presenting in late adolescence or adulthood and includes adult spinal scoliosis, iatrogenic spinal deformity and primary degenerative sagittal imbalance. The authors note that, as life expectancies increase, the prevalence of ASD is rising and more surgical corrections are expected to occur in the future.
“With shifting public sentiment, expanding decriminalization, and a lack of objective data on the potential consequences of cannabis use, it is imperative to identify how baseline cannabis use impacts postoperative outcomes of patients with adult spinal deformity (ASD) undergoing thoracolumbar fusion (TLF),” the study reads.
Half of the sample identified themselves as cannabis consumers and the other half did not. The study looked to compare 90-day complication, 90-day readmission, and two-year revision rates between cannabis users and non-users.
Cannabis consumers experienced significantly lower rates of medical complications during the 90-day period immediately after surgery, 2% for cannabis users and 4.1% for non-users. Overall complication rates were also higher among non-cannabis users compared to cannabis users, 4.8% versus 2.4%, respectively. Those with a history of cannabis use were no more likely than non-users to seek postoperative readmissions.
In their discussion, the authors referenced once more the changing, often favorable perception of cannabis use in the United States and the need to further research the effects of cannabis in neuropathic pain management.
The results, that cannabis is negatively associated with 90-day medical complications, are consistent with previous studies, the authors note. One study, “Marijuana use and mortality following orthopedic surgical procedures,” noted an associated decrease in mortality among cannabis users undergoing common orthopedic procedures. Another study, “Effect of marijuana use on outcomes in traumatic brain injury,” looked at traumatic brain injury patients and similarly found that cannabis users had reduced odds of death over non-users.
However, the authors note the findings are inconsistent with the 2020 study, “The Effects of Marijuana Use on Lumbar Spinal Fusion,” which showed no significant differences in complications between cannabis users and non-user undergoing lumbar spinal fusion. Though, they note that this study was only performed with 102 patients from a single surgeon.
“Compared to patients with ASD who underwent TLF without baseline cannabis use, patients with isolated baseline cannabis use were found to have no increase in odds of incurring 90-day surgical complications or readmissions or revisions two years postoperatively, though reduced odds of experiencing 90-day medical complications were observed,” authors concluded.
“Future prospective, randomized-controlled studies could help further characterize the impact of isolated cannabis use on the postoperative course of surgical patients undergoing complex procedures such as thoracolumbar fusion for adult spinal deformity.”