The question is no longer whether patients use cannabis — it’s what it means for their surgical outcomes.
A recent study takes a closer look at this very issue in patients undergoing elective lumbar fusion. The researchers ask a simple but clinically relevant question: does cannabis use amplify risk in patients who are already medically complex?
The results suggest the answer may be…yes.
Setting the Stage: Four Types of Fusion Patients
The investigators examined 575 patients between ages 35 and 80 undergoing elective one- or two-level lumbar fusions between 2022 and 2025. Patients were sorted into two familiar preoperative buckets: high medical risk and normal risk, based on a preoperative optimization evaluation.
But the authors layered on an additional twist — cannabis use.
This produced four patient categories: High-risk cannabis users (HR-C), High-risk non-users (HR), Normal-risk cannabis users (NR-C) and Normal-risk non-users (NR).
The Headline: Cannabis + High Risk = More Problems
Among the 575 patients, the vast majority were non-users with about a quarter either high-risk cannabis users or normal-risk cannabis users.
While the HR-C group was the smallest cohort, they consistently demonstrated worse perioperative metrics.
Compared with normal-risk non-users, the HR-C group showed 2× higher opioid use after surgery, longer hospital length of stay and higher rates of surgical site infection (SSI).
The patients who were already medically fragile — and also using cannabis — seemed to struggle the most after fusion surgery.
For surgeons accustomed to optimizing smoking cessation, glycemic control, and BMI before elective fusion, cannabis may be emerging as another variable worth discussing during the pre-op visit.
The Complication All-Stars
The regression analyses identified several preoperative factors associated with specific postoperative problems.
Surgical Site Infection
Cannabis use itself showed a significant association with increased SSI rates.
This finding raises interesting biologic questions. Cannabis has complex effects on immune function, wound healing, and inflammatory pathways. While the exact mechanisms remain unclear, the data suggest surgeons may want to view cannabis similarly to other modifiable lifestyle factors.
Emergency Department Visits and Readmissions
Two familiar culprits surfaced tobacco use and mental health conditions.
These factors were linked to higher emergency department utilization and hospital readmissions within the postoperative period.
This reinforces what many surgeons already suspect: the psychosocial context surrounding spine surgery can matter as much as the pathology itself.
Return to the Operating Room
Another cluster of risk factors emerged for patients who eventually required reoperation — alcohol use and higher preoperative pain levels.
This combination might represent a subgroup of patients with both biological and behavioral drivers of poorer recovery.
The Preoperative Optimization Opportunity
The authors emphasize that the real takeaway isn’t simply that cannabis users have worse outcomes — it’s that identifying risk factors allows surgeons to intervene earlier.
In other words, the study strengthens the case for a comprehensive preoperative screening strategy that includes cannabis use, tobacco use, alcohol use, mental health status, and baseline pain severity.
Rather than acting as a reason to deny surgery, these factors can guide targeted optimization strategies, such as behavioral counseling or pain management planning.
For many patients, even modest improvements in modifiable risks could translate into better surgical recovery.
The Big Picture
As cannabis becomes more socially and legally accepted, its impact on surgical care will likely receive increasing attention across multiple specialties.
For spine surgeons, the challenge will be balancing patient autonomy, evolving evidence, and perioperative risk management.
Studies like this one help illuminate the path forward: screen carefully, optimize aggressively, and follow patients closely.
Because sometimes the most important part of spine surgery happens before the incision is ever made.
Origin Study Title: Identifying Key Risk Factors in Elective 1 or 2 Level Lumbar Spine Fusion Patients
Authors: Kwaczala, Andrea T. Ph.D.; Solomito, Matthew J. Ph.D.; McCracken, Caitlin M.A.; Hillery, Charlotte PT, DPT, M.B.A.; Makanji, Heeren M.D.
