“The self-reported use of cannabis has increased since its recent legalization in several states. The primary purpose of this study is to report total knee arthroplasty (TKA) outcomes in patients using cannabis.

RESULTS:

No difference in length of stay was noted between the users (46.9 hours ± 15.7) and nonusers (49.3 hours ± 20.4) (P = .464). In-hospital total morphine equivalents did not differ between the 2 groups (user = 137 ± 104 mg, nonuser = 146 ± 117 mg, P = .634). Postoperative range of motion did not differ between users (128.4° ± 10.4°) and nonusers (126.9° ± 7.5°) (P = .346). No mean differences in follow-up KSS (user = 180.1 ± 24.9, nonuser = 172.0 ± 33.9, P = .106) or total change (user = 61.7 ± 32.8, nonuser = 62.7 ± 30.7, P = .852) in KSS were noted. Likewise, no significant mean differences in Veterans RAND-12 (mental component scores: user = 54.8 ± 9.3, nonuser = 55.9 ± 8.79, P = .472; physical component scores: user = 48.3 ± 9.9, nonuser = 45.8 ± 10.1, P = .145) scores were demonstrated. There were no differences in readmissions (user = 5, nonuser = 4, P = .730) or reoperations (user = 5, nonuser = 2, P = .238).

CONCLUSION:

Cannabis use does not appear to influence (adverse or beneficial) short-term outcomes in patients undergoing a primary TKA. Further studies are warranted to determine the efficacy and safety of cannabis as a constituent of multimodal pain management following TKA before endorsements can be made by orthopedic surgeons.”

https://www.ncbi.nlm.nih.gov/pubmed/31072746

https://www.arthroplastyjournal.org/article/S0883-5403(19)30347-X/fulltext