Cannabis Use in Orthopaedic Surgery: Effects on Fracture Healing, Opioid Requirements, and Clinical Outcomes

Cannabis is commonly used by patients presenting for orthopaedic care, including musculoskeletal pain, sleep disturbances, anxiety, or recreational purposes. Because orthopaedic care depends on predictable bone healing, effective perioperative analgesia, and prevention of postoperative complications, the interaction between cannabis exposure and these domains remains uncertain. This narrative review synthesizes mechanistic, preclinical, and clinical evidence regarding the effects of cannabis and cannabinoid exposure on fracture healing, opioid requirements, and broader clinical outcomes in orthopaedic surgery, and draws on literature gathered via PubMed and Embase supplemented by manual review of references and a structured semantic search using an artificial intelligence assisted platform that screened more than 100 orthopaedic and perioperative studies. Experimental studies show that the endocannabinoid system influences osteoclast and osteoblast function and that smoked cannabis can impair cancellous bone healing in animal models, while cannabidiol may enhance fracture repair. In addition, observational data in humans associate heavy cannabis use with lower bone mineral density, higher fracture risk, and, in some settings, increased postoperative complications or risks of malunion or nonunion. Across heterogeneous orthopaedic and mixed surgical cohorts, chronic cannabis use is frequently associated with higher postoperative pain scores and greater opioid consumption, while small trials of pharmaceutical cannabinoids demonstrate at most modest opioid-sparing effects that have not translated into clinically important perioperative benefits. Taken together, current evidence does not support routine perioperative cannabis use to reduce opioid requirements and raises concerns regarding bone health and selected postoperative complications, particularly among heavy users, underscoring the need for systematic screening, counseling to avoid inhaled cannabis around fracture fixation or fusion, and reliance on validated multimodal analgesic strategies rather than cannabinoids.