Medical cannabis and its efficacy/effectiveness on the management of osteoarthritis pain and function.

Objective: Despite pharmacological treatments for osteoarthritis (OA), more individuals are choosing medical cannabis for OA symptom management and for mitigating opioid prescriptions for OA. This systematic review examines the global evidence of medical cannabis use on OA pain and function.

Methods: The search was completed in MEDLINE (PubMed), Embase, and CINAHL within the past 10 years (2012-2022). We limited the search to English language articles. We did not include grey literature or case studies. Participant demographics included all adult individuals with OA who were using medical cannabis for OA. Study quality and risk of bias were evaluated using the Grading of Recommendations, Assessment, Development and Evaluations framework; and the Risk of Bias in Non-randomized Studies of Interventions tool. We used a narrative synthesis approach.

Results: Overall, 7 studies were included: 2 randomized controlled trials (RCT) and 5 observational studies. Only 1 of the 2 RCTs reported improvements in pain for cannabis users. All 5 observational studies reported an improvement in pain levels, reduction of opioid use, and/or improvement in overall OA function. Despite high risk of bias ratings and low study quality, the consensus across studies was that medical cannabis use was effective for a subgroup of individuals suffering from OA pain.

Conclusions: There is low quality evidence to support medical cannabis use as a substitute for primary pharmacological treatment of OA. However, this does not negate the observations that medical cannabis may provide therapeutic relief for a subset of patients.

Systematic review propsero registration: CRD42022354026.