Cannabis use for chronic musculoskeletal pain on the rise, finds study

ROSEMONT, Ill. —The use of medical cannabis has garnered a lot of recent attention, especially as parts of the United States and Canada have legalized its use. While 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. According to a new study released as part of the American Academy of Orthopaedic Surgeons' (AAOS) Virtual Education Experience, 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. Additionally, two-thirds of non-users 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, Department of Surgery at the University of Toronto, and orthopaedic surgeon, Arthritis Program, University Health Network. "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 and what they perceive the efficacy to be."

Currently, 33 states, District of Columbia, Guam, Puerto Rico and U.S. Virgin Islands have approved medical marijuana/cannabis programs.[i] The majority of U.S. adults (59%) believe marijuana should be legal for medical and recreational use, and 32% say it should be legal for medical use only, according to a September 2019 Pew Research Center survey.[ii] The U.S. Food and Drug Administration (FDA) has only approved one prescription drug that contains a substance derived from marijuana.[iii]

The study, "Understanding the Rate and Perceived Efficacy of Cannabis Use for the Management of Chronic Musculoskeletal Pain," looked at 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, one in five 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 cannabis users, only 26% received a recommendation from a physician. The majority were recommended cannabis for chronic MSK pain by a friend or family member. 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," said Dr. Leroux. "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 vs. 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 and 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," said Dr. Leroux. "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."