A new study published in the Journal of the American Academy of Orthopaedic Surgeons has found that patients who used marijuana before undergoing total hip arthroplasty (THA) did not face a higher risk of complications, unlike those who used tobacco.

Researchers at Yale School of Medicine analyzed data from more than 494,000 THA patients between 2010 and 2021. Patients were divided into four groups: nonusers, tobacco users, cannabis users, and those who used both. After matching for age, sex, and comorbidities, each group included 1,897 patients for comparison.

The analysis revealed that tobacco-only users were at significantly greater risk of serious complications, including sepsis and pneumonia, within 90 days of surgery. Patients who used both tobacco and cannabis faced even broader risks, such as myocardial infarction, pneumonia, and readmission.

By contrast, cannabis-only users did not show a statistically significant increase in complications compared to nonusers. The researchers noted that this distinction is important as marijuana use continues to expand, offering reassurance for patients and physicians navigating preoperative risk assessments.

The findings highlight a clear difference between the effects of tobacco and cannabis on surgical outcomes, with marijuana use alone not posing the same level of perioperative risk.