Cannabinoid Use Increased while Opioid Use Decreased among VA Patients Undergoing Total Joint Replacement
BACKGROUND:
Cannabis has been legalized for medical and/or recreational use in 30 states, and some believe that the cannabis plant and its derivatives (cannabinoids) can play a role in treating chronic pain, though definitive evidence is lacking. Evidence also is limited regarding cannabinoid use in total joint arthroplasty (TJA) patients. This retrospective, single-institution (VA Palo Alto) study sought to determine whether preoperative cannabinoid use and opioid use increased or decreased over a 6-year interval among total hip and knee arthroplasty (THA and TKA) patients – and whether complications were associated with cannabinoid use. Using data from the electronic health record and VA’s Surgical Quality Improvement Program (VASQIP), investigators reviewed total joint replacement cases from 2012 – 2017. During this time period, 1,778 operations were performed on 1,519 Veterans (1,161 TKAs and 617 THAs). A pre-operative urine toxicology screen was used to identify Veterans who screened positive for cannabinoids or opioids. Investigators also assessed patient demographics, surgery type, and American Society of Anesthesiologists’ Physical Status Classification System (ASA) score.
FINDINGS:
- The use of cannabinoids in Veterans undergoing total joint arthroplasty was far greater than previously reported in the literature, while opioid use decreased. Over the six-year study period, cannabinoid use increased more than 60%, while opioid use decreased about 30%.
- When compared with patients not using cannabinoids, investigators were unable to find a difference in rates of readmission, infection, reoperation, or other complications captured in the VASQIP database, even after controlling for age, gender, surgery type, and ASA score.
- Cannabinoid users were more likely to also be taking opioids than non-users, and they were significantly younger than both non-users (62 vs.66 years) and opioid users (63 vs. 65 years).
IMPLICATIONS:
- With the increase in cannabis use among VA patients, further study is needed to understand the effects of cannabis and its derivatives on the outcomes of total joint replacement.
AUTHORS’ NOTE:
- Study findings DO NOT provide evidence as to a causal link between increases in cannabis use and reductions in opioid use. During the study period, VA implemented national programs that substantially reduced overall opioid use across all patients.
LIMITATIONS:
- Results are from one VAMC in California, a state that legalized medical cannabis in 1996 (though cannabinoids are still not available through the federal healthcare system).
AUTHOR/FUNDING INFORMATION:
Drs. Giori and Sox-Harris are part of HSR&D’s Center for Innovation to Implementation (Ci2i) in Palo Alto, CA.
Denduluri S, Woolson S, Indelli P, Mariano E, Sox-Harris A, and Giori N. Cannabinoid and Opioid Use among Total Joint Arthroplasty Patients: A 6-Year, Single Institution Study. Orthopedics. October 1, 2020; Online ahead of print.
