Cannabis Use Does Not Affect Outcomes After Total Hip Arthroplasty

Background: Cannabis use in patients undergoing arthroplasty has increased with ongoing legalization throughout the United States. The purpose of this study was to report total hip arthroplasty (THA) outcomes in patients self-reporting cannabis use.

Methods: There were 74 patients who underwent primary THA from January 2014 to December 2019 at a single institution with minimum one-year follow-up who had their self-reported cannabis use retrospectively reviewed. Patients who had a history of alcohol or illicit drug abuse were excluded. A match control was conducted based on age; body mass index (BMI); sex; Charlson Comorbidity Index; insurance status; and use of nicotine, narcotics, anti-depressants, or benzodiazepines to patients undergoing THA who did not self-report cannabis use. Outcomes included Harris Hip Score (HHS), Hip Disability and Osteoarthritis Outcome Score for Joint Reconstruction (HOOS JR), in hospital morphine milligram equivalents (MMEs) consumed, outpatient MMEs prescribed, in hospital lengths of stay (LOS), postoperative complications, and readmissions.

Results: There was no difference in the preoperative, postoperative, or change in HHS or HOOS JR between cohorts. There was also no difference in hospital MMEs consumed (102.4 vs 101, P=0.92), outpatient MMEs prescribed (119 vs 156, P=0.11) or LOS (1.4 vs 1.5 days, P=0.32). Also, readmissions (4 vs 4, P=1.0) and reoperations (2 vs 1, P=0.56) were not different between groups.

Conclusion: Self-reported cannabis use does not influence one-year outcomes after THA. Further studies are warranted to determine the efficacy and safety of perioperative cannabis use after THA to help guide orthopaedic surgeons in counseling patients.