Cannabidiol or CBD is one of more than 400 possible compounds extracted from the hemp plant Cannabis Sativa. Of those 400 compounds, close to 65 of them are classified as cannabinoids. There are eighteen chemical groups present in the molecule, including amino acids, fatty acids, nitrogenous compounds, terpenes, hydrocarbons, and sugars. The chemical groups are tied to the CBD’s pharmacological properties. The human body has endocannabinoid receptors that are present on its cells. These receptors are activated when there is a molecular binding with the CBD molecule.
Unlike THC, the psychoactive molecule in the cannabis plant, CBD does not have psychoactive effects but does exert anxiolytic, anti-psychotic, and alerting effects. Interestingly, the most widespread neurotransmitter receptors in the brain are CBD1. These same receptors are found widely distributed in bone as well. CBD2 receptors are found primarily in the cells of the immune system. The natural endocannabinoid molecules our body makes naturally are anandamide and 2-arichidonoylglycerol (2AG). These endogenous pathways are involved in many physiologic functions, including pain modulation, accounting for their reported efficacy in the setting of both acute and chronic pain.
Cannabinoid receptors can be found in all species, from sponges to humans. These receptors are meant to respond to our endogenous cannabinoid system and account for the bioactivity of exogenous sources of both CBD and the psychoactive component of marijuana compounds, delta-9-THC.
Other authors have reported on the ability of cannabinoid ligands, like CBD, to enhance fracture healing by regulating bone mass. CBD stimulates mRNA expression of Plod 1 in primary osteoblast cultures, encoding an enzyme that catalyzes lysine hydroxylation. Hydroxylation of lysine enhances collagen cross-linking and stabilization, and type one collagen is the primary constituent of bone. CBD has been shown to increase the maximal load and work-to-failure, but not the stiffness of rat femurs. It is currently unknown whether this accelerated bone healing will carry over to the human clinical model. CBD is not psychoactive but has pain-relieving and anti-inflammatory properties.
Thus far, it appears that CBD is a non-toxic, safe, and non-psychogenic option to treat pain and inflammation associated with orthopedic manifestations of the disease, including fracture and arthritis. Some applicable orthopedic conditions include spondylosis (spine disease), facet arthropathy, acute and subacute pain, surgical pain, and perhaps most importantly, arthritic pain. The safety and efficacy profile of CBD compounds suggest a potential role as a first-line treatment option in the setting of some organic joint diseases like arthritis.
 Yankel Gabet et al., “Canabidiol, a Major Non-Psychotropic Cannabis Constituent Enhances Fracture Healing and Stimulates Lysl Hydroxylase Activity in Osteoblasts.” Journal of Bone Mineral Research, March 19, 2015 doi: 10.1002/jbmr.2513