Medical cannabis has garnered a great deal of attention recently, especially as parts of the US and Canada have legalized its use. Although it has been studied in cancer and nerve pain, not much is known about the usage rate and its efficacy in managing chronic musculoskeletal (MSK) pain.
A new study from the University of Toronto is bringing some clarity to the issue: Researchers there found that up to 20% of patients presenting to an orthopaedic surgeon with chronic MSK pain are using cannabis to manage their pain, with many reporting success. In addition, two thirds of non-users say they are interested in using it for the management of MSK pain, prompting a need to further study its effects.
“Over time, we’ve certainly seen an increase in the use of cannabis to manage musculoskeletal pain,” said Timothy Leroux, MD, Assistant Professor in the Department of Surgery at the University of Toronto. “There is definite interest to see if cannabis can be used to manage chronic MSK pain, as opposed to other conventional treatments such as anti-inflammatories and opioids. With this study, we wanted to get a lay of the land as to who is using it, what proportion are using [cannabis], and what they perceive the efficacy to be.”
Currently, 33 states, the District of Columbia, Guam, Puerto Rico, and the US Virgin Islands have approved medical marijuana/cannabis programs.  The majority of adults in the US (59%) believe marijuana should be legal for medical and recreational use, and 32% say it should be legal for medical use only. 
The study from the University of Toronto examined the rate and pattern of cannabis use among patients with chronic MSK pain, self-reported efficacy, and potential barriers to cannabis use for non-users. Of 629 patients enrolled in the study, 1 in 5 reported that they are currently using or have used cannabis to manage their chronic MSK pain, of which 90% reported it effective in managing their pain and 40% said it decreased their use of other pain medications. Fifty-seven percent said it was more effective than other pain medications
Of the cannabis users, only 26% received a recommendation for cannabis for chronic MSK pain from a physician, with the majority having a friend or family member recommending cannabis for pain. The most common cannabinoid used was cannabidiol (39%) and the most common route of use was the ingestion of oils (60%).
“Most doctors, especially orthopaedic surgeons, don’t have prescribing power for cannabis, so there is minimal physician oversight when it comes to cannabis use to manage chronic MSK pain,” Dr. Leroux said. “To complicate things, it’s a little bit of a Wild West in the cannabis industry in terms of what you get in a product, namely actual versus labelled composition, and consistency.
“Another challenge is that we don’t fully know what products, formulations, dosages, and routes of administration are best to manage chronic MSK pain. Given the high rate of use observed in this study [with] little physician oversight, there’s an impetus for us as a medical community to try to understand what role, if any, cannabis may serve in the management of chronic MSK pain.”
The study found that patients who used cannabis for chronic MSK pain:
- Have multiple conditions, including depression, back pain, chronic pelvic pain, and chronic neck pain (P< 0.001)
- Were more likely to report a greater burden of pain, including a greater total number of painful areas (P< 0.001), a history of pain clinic visits (P=0.003), a longer duration of a painful condition (P=0.003), and a higher rate of pain medication use, specifically muscle relaxants (P=0.002) and opioids (P=0.002)
- Were more likely to use or have used cannabis for recreation (53.2%; P=0.001)
Sixty-five percent of non-users (n=489) reported they would be interested in using cannabis to control MSK pain, but lacked knowledge regarding efficacy, access, commonly used products, doses, and methods to administer.
“For those who didn’t use cannabis, we found stigma, access and knowledge of cannabis to similarly be reported as barriers to use,” Dr. Leroux said. “We tend to associate cannabis with a younger age due to recreational use, but in our study, age was not a significant factor influencing use for the management of chronic MSK pain. In the current study, patients reported use well into their 80s, many whom we assumed would want to use more conventional products.
“We’d like to repeat this study in the next few years to see how use and demographics change as people become more comfortable with the idea of cannabis as the norm as well as what role state legalization plays in patients’ attitudes towards its use.”
Leroux TS, Maldonado-Rodriguez N, Sundararajan K, Gandhi R, Rampersaud R, Ravi B, Veillette C, Clarke HA. Understanding the Rate and Perceived Efficacy of Cannabis Use for the Management of Chronic Musculoskeletal Pain, Poster P0749. AAOS Virtual Education Experience.
- National Conference of State Legislatures. State Medical Marijuana Laws. https://www.ncsl.org/research/health/state-medical-marijuana-laws.aspx. Updated Oct. 16, 2019. Accessed May 28, 2020.
- Pew Research Center. Two-thirds of Americans support marijuana legalization. https://www.pewresearch.org/fact-tank/2019/11/14/americans-support-marijuana-legalization/. Accessed May 28, 2020.