Cannabis and Nicotine Before Spine Fusion: What a 144,000-Patient Cohort Study Found
| Audience | Spine surgeons, anesthesiologists, primary care and pain physicians counseling patients before elective fusion, and patients with documented cannabis or nicotine use considering cervical or lumbar spine surgery |
| Primary Topic | A retrospective cohort study of cannabis and nicotine use and postoperative outcomes after cervical and lumbar interbody fusion |
| Source | Read the full study in N Am Spine Soc J |
Table of Contents
- Cannabis and Nicotine Before Spine Fusion: What a 144,000-Patient Cohort Study Found
- How to Read a Large Registry Study Without Overclaiming Causation
- The Same Study Can Mean Different Things Depending on the Question Being Asked
- Disclosure Matters More Than Guilt
- A Case for Routine Preoperative Screening
- Planning Around Documented Use, Not Assumptions
- The Exposure Definition Is the Whole Story
- Utilization Signals Are as Important as Complication Rates
- Small Exposed Groups, Big Claims Risk
- Real Strength, Real Limits of Registry Data
- What Better Perioperative Cannabis Evidence Would Need
- Frequently Asked Questions
Cannabis and Nicotine Before Spine Fusion: What a 144,000-Patient Cohort Study Found
A June 2026 cohort study of more than 144,000 spine fusion patients found that documented cannabis-related diagnoses, not casual cannabis use, tracked with higher odds of pain, psychiatric, and opioid-related complications after surgery. Patients with both cannabis and nicotine diagnoses showed the broadest risk elevation, and the findings support preoperative screening rather than any assumption that cannabis reduces opioid needs after fusion.
| Study Type | Retrospective cohort study using a federated national EHR database |
| Data Source | TriNetX Research Network (over 200 US healthcare organizations) |
| Population | 144,488 adults undergoing primary cervical or lumbar interbody fusion, 2015 to 2022 |
| Groups Compared | Nonusers (75.4%), nicotine-only (23.1%), cannabis-only (0.4%), concurrent cannabis and nicotine (1.2%) |
| Cannabis Definition | ICD-10 cannabis-related disorder or cannabis poisoning codes, reflecting documented problematic use, not general recreational use |
| Key Finding, Cannabis-Only | Higher odds of radiculopathy, cauda equina syndrome, chronic pain, myocardial infarction, acute respiratory failure, acute kidney injury, depression, opioid use disorder, rehospitalization, and ED use |
| Key Finding, Concurrent Use | Broadly elevated risk across neurologic, surgical, medical, psychiatric, and utilization outcomes, generally the highest adjusted odds of any group |
| Notable Null Finding | Venous thromboembolism was not significantly associated with any exposure group |
| Journal | North American Spine Society Journal |
| Published | June 10, 2026 |
| PMID | 42434720 |
| DOI | 10.1016/j.xnsj.2026.100915 |
Among 144,488 adults who underwent cervical or lumbar interbody fusion, the 540 patients with a documented cannabis-only diagnosis had higher adjusted odds of radiculopathy, cauda equina syndrome, chronic pain, myocardial infarction, acute respiratory failure, acute kidney injury, depression, and opioid use disorder, along with more rehospitalizations and emergency department visits.
The 1,677 patients with both cannabis and nicotine diagnoses fared the worst overall, with broadly elevated risk spanning neurologic, surgical, medical, psychiatric, and healthcare-utilization outcomes, including higher rates of infection and pseudarthrosis.
Cannabis is often used because patients and some clinicians expect it to ease pain and reduce opioid requirements after surgery. This cohort found the opposite pattern: rather than demonstrating a protective, opioid-sparing effect, documented cannabis-related diagnoses identified patients with more opioid-related complications, not fewer.
The authors frame this as a marker of perioperative vulnerability rather than evidence that cannabis itself directly worsens fusion outcomes.
This is a retrospective, registry-based study, not a randomized trial, and it cannot establish that cannabis use directly causes worse surgical outcomes. Patients with a documented cannabis-related disorder or poisoning code likely differ from average cannabis users in ways the database cannot fully capture, including heavier use patterns, other substance use, mental health comorbidity, and socioeconomic factors that independently affect surgical recovery.
Because cannabis exposure was defined by clinically coded diagnoses rather than a validated use questionnaire, the findings describe a subgroup of patients with a documented problematic-use history, not cannabis users in general, including many medical cannabis patients who would never receive such a diagnosis code.
For patients using cannabis before elective spine fusion, the responsible counseling message is not that cannabis use guarantees a bad outcome. It is that a documented cannabis-related diagnosis, especially alongside nicotine use, identifies a group whose perioperative risk profile deserves specific attention, transparent disclosure, and coordinated planning before surgery.
Surgeons and primary care clinicians should ask directly about cannabis and nicotine use before elective fusion, document it accurately, and use that information to inform realistic expectations about pain control, complication risk, and recovery, rather than assuming cannabis will reduce postoperative opioid needs.
Perioperative cannabis counseling has often been shaped by anecdotal reports of pain relief and opioid-sparing potential, with comparatively few large studies looking directly at surgical complication data.
This cohort adds to a growing body of orthopedic and spine literature, including prior work on cannabis and revision risk after lumbar fusion, suggesting that documented cannabis use, particularly when combined with nicotine, is more often a marker of perioperative vulnerability than a therapeutic advantage in the surgical setting.
Patients frequently tell me they expect cannabis to help them get through surgery with less pain and fewer opioids. This study is a useful reality check: a documented cannabis-related diagnosis in this cohort tracked with more complications, not fewer, and combined cannabis and nicotine use tracked with the broadest risk of all.
My takeaway for my own patients considering spine surgery is not to abandon cannabis use as a talking point, but to bring it into the open. I would rather know about a patient’s cannabis and nicotine use well before surgery, discuss realistic expectations for pain control, and coordinate perioperative planning than have that information surface only after a complication.
How to Read a Large Registry Study Without Overclaiming Causation
Large database studies like this one are powerful for spotting patterns across huge populations, but they are easy to overread if a reader treats an association as proof of a direct cause.
The most useful approach is to separate what the numbers show from what they can plausibly explain.
A Four-Step Reading Frame
Start With the Data Source
This is a retrospective analysis of deidentified electronic health records from a federated research network, not a randomized trial, so it excels at detecting associations across a large population but cannot isolate cause and effect.
Look Closely at How Exposure Was Defined
Cannabis use here means a clinically coded cannabis-related disorder or poisoning diagnosis, a narrower and more severe definition than cannabis use in general, which shapes how far the findings can be generalized.
Separate Cannabis-Only From Concurrent Use
Cannabis-only use and combined cannabis-and-nicotine use showed different risk patterns, with concurrent use carrying the broadest elevation, so lumping every substance-use group together would blur an important distinction.
Translate the Result Into Screening, Not Prohibition
The most defensible clinical use of this study is to support routine preoperative screening and counseling, not to withhold surgery from patients who use cannabis or to assume every cannabis user faces the same risk.
The Same Study Can Mean Different Things Depending on the Question Being Asked
Scientific papers rarely answer a single question. Patients, clinicians, researchers, policymakers, and critics often read the same data differently. The perspectives below explore how this study looks through several evidence-based lenses.
Disclosure Matters More Than Guilt
If you use cannabis and are considering spine fusion, this study is not a reason to panic or to hide your use from your surgical team. The point is that documented cannabis use, especially alongside nicotine, was linked to more complications, so your care team needs accurate information to plan your surgery and recovery well.
Being honest about cannabis and nicotine use before surgery gives your surgeon and anesthesiologist the chance to adjust expectations, monitoring, and pain-control planning around your specific risk profile.
A Case for Routine Preoperative Screening
For spine surgeons, this cohort reinforces that cannabis-related diagnoses deserve the same systematic preoperative attention already given to nicotine use, since both independently and jointly tracked with worse outcomes across neurologic, surgical, medical, and utilization measures.
The authors explicitly recommend routine preoperative screening and targeted counseling, which this data set supports given the scale of the sample and the consistency of findings across cervical and lumbar procedures.
Planning Around Documented Use, Not Assumptions
Anesthesiologists and perioperative teams may be interested that concurrent cannabis and nicotine users showed the broadest risk elevation, which argues for coordinated planning across surgical and anesthesia teams rather than treating cannabis as a minor detail.
This study does not provide guidance on perioperative cannabis cessation timing or anesthetic dosing adjustments, so those decisions still rely on separate clinical protocols and judgment.
The Exposure Definition Is the Whole Story
From an addiction-medicine perspective, the most important detail in this study is that cannabis exposure was defined by a diagnosed cannabis-related disorder or poisoning code, not simple cannabis use. That means the cannabis-only group likely already carried more clinical severity, more comorbidity, and less social stability than a typical medical cannabis patient.
This distinction matters enormously for how the findings should be applied to the much larger population of people who use cannabis without ever receiving such a diagnosis.
Utilization Signals Are as Important as Complication Rates
Beyond individual complications, the study found higher rehospitalization and emergency department use among cannabis-only patients, and broadly elevated utilization among concurrent users. From a patient-safety standpoint, that utilization signal is itself clinically meaningful, since it points to a group needing closer post-discharge follow-up.
Health systems planning post-fusion care pathways may want to flag documented cannabis and nicotine use as risk factors for early return visits, independent of any single complication type.
Small Exposed Groups, Big Claims Risk
A skeptical reader should note that the cannabis-only group included only 540 of 144,488 patients, a small fraction of the total cohort. Estimates built on a comparatively small, clinically severe subgroup can be sensitive to unmeasured confounding and coding inconsistencies across the many contributing health systems.
Skepticism here should sharpen the takeaway, not erase it: the direction and consistency of the associations across multiple outcome domains make the signal worth taking seriously, even while the precision of any single estimate should be interpreted cautiously.
Real Strength, Real Limits of Registry Data
Methodologically, this study benefits from a large, multi-institution federated database and multivariable adjustment for demographics, comorbidities, spine region, and surgical approach, which is a meaningful strength compared with single-center case series.
It remains limited by its reliance on ICD-10 coding to define exposure, its retrospective design, and its inability to capture cannabis product type, dose, frequency, or route, all of which limit causal interpretation and mechanistic understanding.
What Better Perioperative Cannabis Evidence Would Need
Stronger future research would need validated, self-reported cannabis use data alongside clinical coding, information on product type, dose, frequency, and timing relative to surgery, and prospective designs that can better separate cannabis’s direct physiological effects from the comorbidities associated with a cannabis-related disorder diagnosis.
Until that research exists, this study is best used as a screening and counseling tool rather than a definitive statement about cannabis and surgical risk.
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Frequently Asked Questions
Does this study prove cannabis use causes worse outcomes after spine fusion?
No. It is a retrospective cohort study that found associations between documented cannabis-related diagnoses and worse outcomes, but it cannot prove that cannabis use directly causes those complications.
How was cannabis use defined in this study?
Cannabis exposure was identified using ICD-10 codes for cannabis-related disorder or cannabis poisoning, meaning the cannabis-only group reflects clinically documented problematic use rather than general recreational or medical cannabis use.
What outcomes were worse in cannabis-only patients?
Cannabis-only patients had higher odds of radiculopathy, cauda equina syndrome, chronic pain, myocardial infarction, acute respiratory failure, acute kidney injury, depression, opioid use disorder, and increased rehospitalization and emergency department use.
Did cannabis reduce opioid use after spine fusion in this study?
No. Rather than showing an opioid-sparing effect, documented cannabis-related diagnoses were associated with more opioid-related complications, not fewer.
What happened in patients who used both cannabis and nicotine?
Concurrent cannabis and nicotine users showed the broadest risk elevation of any group, with higher rates across neurologic, surgical, medical, psychiatric, and healthcare-utilization outcomes, including infection and pseudarthrosis.
Was blood clot risk higher in cannabis or nicotine users?
No. Venous thromboembolism was not significantly associated with any exposure group in this study.
How many patients were in the cannabis-only group?
540 of the 144,488 patients in the cohort were classified as cannabis-only users, a small fraction of the total sample, which should temper confidence in the precision of that group’s estimates.
Does this study apply to all cannabis users considering spine surgery?
Not directly. Because cannabis exposure was defined by a diagnosed cannabis-related disorder or poisoning code, the findings describe a more clinically severe subgroup and may not generalize to typical medical or occasional cannabis users.
What should patients do with this information before spine surgery?
Patients should disclose cannabis and nicotine use to their surgical and anesthesia teams so that realistic expectations, monitoring, and perioperative planning can be built around their individual risk profile.
What is the most practical clinical takeaway from this study?
The most practical takeaway is that documented cannabis use, and especially combined cannabis and nicotine use, should prompt routine preoperative screening and counseling rather than an assumption that cannabis will ease recovery or reduce opioid needs.
