The Impact of Preoperative Cannabis Use on Postoperative Pain and Opioid Use in Orthopaedic Surgery Patients: A Scoping Review

Background: The use of cannabis for medical and recreational purposes has become increasingly prevalent. Emerging evidence suggests that postoperative cannabis-based medications influence postoperative opioid use for analgesia, although the impact of preoperative cannabis use on acute orthopaedic surgical outcomes remains unclear. The purpose of this study was to explore current literature regarding the associations of preoperative cannabis use with pain and opioid requirements after undergoing orthopaedic surgery. Methods: A scoping review was conducted through a search of the PubMed, EMBASE, and Scopus databases. Two independent reviewers extracted information on population, measure of cannabis use, and postoperative outcomes, including Patient-Reported Outcomes Measurement Information System scores, pain, and morphine milligram equivalents. Results: We identified 1,025 studies for potential inclusion. After screening all abstracts and titles, 19 orthopaedic studies were included, comprising 19,719 patients. Most were retrospective cohort studies, with 11 evaluating opioid use, three evaluating postoperative pain outcomes, and five evaluating both. Among the pain-related studies, three reported higher pain scores in their cannabis-user cohorts, one reported lower pain scores among cannabis users, and the remaining found no differences in pain. The studies evaluating opioid use found no notable difference in morphine milligram equivalent consumption between cannabis users and nonusers. Discussion: Most evidence suggests that preoperative cannabis use has no effect on opioid use after orthopaedic surgery. Few articles investigated the associations of preoperative cannabis use with postoperative pain, and results were mixed, with only one study evaluating cannabis use in upper extremity surgical patients, suggesting the need for further exploration in some fields. No studies were able to measure duration of cannabis use, method of consumption, or potency because the use was either self-reported or based on a diagnosis of cannabis use disorder, indicating the need for future studies to stratify preoperative cannabis use by methods of ingestion and amount consumed.