Among the diseases that can affect the musculoskeletal system, causing pain and inflammation, problems affecting the knees, one of the most complex joints in the human body due to its crucial role in maintaining posture and movement, stand out. Knee pain can have different causes and manifest itself in acute or chronic form, causing varying degrees of personal and occupational incapacity and negatively influencing the quality of life of the sufferer.
One of the most frequent causes of knee pain is osteoarthritis (OA), which occurs in 4% of the population and represents the eleventh leading cause of disability worldwide.
Most common causes of knee pain
The knee is a joint composed of:
- Bones: femur, tibia and kneecap
- Ligaments: medial and lateral collateral, anterior cruciate and posterior cruciate ligaments
- Cartilage, including the meniscus
- Synovial fluid
- Muscles and tendons responsible for their movement
There are different problems that can affect the knees, causing pain and inflammation, and they can occur at any age, and may be related to specific mechanical trauma, the presence of a disease or wear and tear due to the passage of time. Being overweight can play a crucial role in the development of knee pain and problems, as can many physical and heavy sports or jobs.
The most common causes of knee pain can be:
- Presence of osteoarthritis or osteoarthritis: these represent the most frequent chronic problems, involving wear and tear and degeneration of the cartilage causing pain, swelling and stiffness
- Ligament injuries (sprains): very frequent among sportsmen and women, they can be of different degrees causing strain, partial or total rupture of the ligament
- Partial or total meniscus injuries
- Tendon injuries
- Bone fractures
- Muscular problems
Diagnóstico y tratamientos para el dolor de rodilla
Diagnosis is made by physical examination and using techniques such as arthroscopy and magnetic resonance imaging.
Depending on the severity of the problem, analgesic and anti-inflammatory drugs are usually prescribed as well as compensatory physical exercise and weight control strategies, as postural changes due to knee problems can also lead to back pain.
In the most severe cases, surgery is necessary to heal bone fractures, tendon, ligament and meniscus injuries.
How CBD works against knee pain
The endocannabinoid system, which is dedicated to maintaining the psycho-physical balance of our organism, is present in both the muscular and skeletal systems, participating in the processes of recovery from an injury or fracture and also modulating inflammatory processes and pain sensation thanks to its close relationship with the nervous and immune systems (3).
Different studies have observed the presence of endocannabinoid receptors CB1 and CB2 in the synovial fluid, and in people suffering from osteoarthritis or rheumatoid arthritis, the presence of the main endocannabinoids such as anandamide and 2-AG, as well as the FAAH degrading enzyme, has also been recorded. (4) (5) (6)
CBD, thanks to its modulatory activity on the endocannabinoid system, can alleviate knee pain resulting from various causes. In particular, CBD would provide
- An analgesic and anti-inflammatory effect, to relieve acute problems and chronic pain of both neuropathic and rheumatological origin.(4)
- Neuroprotective and immunomodulatory effect, to prevent neurological problems and slow down neurodegenerative processes (9).
- Stimulating effect on bone metabolism, facilitating recovery from possible fractures and influencing collagen production (7).
Studies on the effect of CBD in animals
Numerous studies have recorded an analgesic, anti-inflammatory and neuroprotective effect of CBD in experimental models of osteoarthritis in animals, also observing a preventive effect against possible neurological damage and consequent neuropathic pain, and confirming the capacity to slow down the degenerative process, with doses of 5 mg/kg or 25 mg/day.
While most of the studies cited above have used the endovenous or transdermal route, there is one study carried out on dogs with OA using the ingested route: the results have shown significant improvements in symptoms after taking 4 mg of CBD a day for a month.
Studies on the effect of CBD in humans
Preclinical evidence shows the beneficial effects of CBD in relieving pain and reducing inflammation in joints, demonstrating how phytocannabinoid treatments can represent a safe, effective and economical option for treating acute or chronic problems such as arthritis and osteoarthritis of the knee.
More specifically, significant improvements have been reported following transdermal application of synthetic CBD and a clinical trial is currently under preparation to study the effectiveness of oral applications of CBD in patients with osteoarthritis of the knee.
How to take CBD for knee pain
According to studies, it is possible to take CBD internally in inhaled, sublingual and ingested form, as well as externally in topical and transdermal form, to treat knee pain.
The inhaled form, which ensures maximum and immediate effect, is used to cope with acute pain, using what is needed at the time.
The sublingual form (not regulated in Spain) is used to obtain a continuous and stable effect and represents a better option compared to the ingested form (not regulated in Spain). In general, it is advisable to start with a low to medium concentration CBD oil (5%-10%), starting with minimal doses and gradually increasing every two days until the effects appear. In this case, it is highly recommended to seek advice and monitoring by a specialised health professional.
Through the topical route, the effect is concentrated in the area of application, so it is also highly recommended to use CBD-rich oils, creams and ointments that can be applied 3-4 times a day, gently massaging the entire knee area until they are completely absorbed.
There are also transdermal patches on the market (including knee pads) which, in addition to having a direct effect on the area of application, allow a systemic effect to be obtained.
Precautions: Is CBD safe?
CBD is a very safe substance even if used in large quantities, but care should be taken when taking medication or if you have heart or blood pressure problems. For this reason in these cases it is always advisable to contact a health professional.
Possible adverse effects
Adverse effects are usually mild to moderate in severity and may include tiredness, drowsiness, dry mouth, dizziness and decreased appetite.
- Donvito, G., Nass, S. R., Wilkerson, J. L., Curry, Z. A., Schurman, L. D., Kinsey, S. G., & Lichtman, A. H. (2018). The Endogenous Cannabinoid System: A Budding Source of Targets for Treating Inflammatory and Neuropathic Pain. Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology, 43(1), 52–79.
- Rzeczycki, P., Rasner, C., Lammlin, L., Junginger, L., Goldman, S., Bergman, R., Redding, S., Knights, A. J., Elliott, M., & Maerz, T. (2021). Cannabinoid receptor type 2 is upregulated in synovium following joint injury and mediates anti-inflammatory effects in synovial fibroblasts and macrophages. Osteoarthritis and cartilage, 29(12), 1720–1731.
- Richardson, D., Pearson, R. G., Kurian, N., Latif, M. L., Garle, M. J., Barrett, D. A., Kendall, D. A., Scammell, B. E., Reeve, A. J., & Chapman, V. (2008). Characterisation of the cannabinoid receptor system in synovial tissue and fluid in patients with osteoarthritis and rheumatoid arthritis. Arthritis research & therapy, 10(2), R43.
- Valastro, C., Campanile, D., Marinaro, M., Franchini, D., Piscitelli, F., Verde, R., Di Marzo, V., & Di Bello, A. (2017). Characterization of endocannabinoids and related acylethanolamides in the synovial fluid of dogs with osteoarthritis: a pilot study. BMC veterinary research, 13(1), 309. https://doi.org/10.1186/s12917-017-1245-7
- Kogan NM, Melamed E, Wasserman E, et al. Cannabidiol, a Major Non-Psychotropic Cannabis Constituent Enhances Fracture Healing and Stimulates Lysyl Hydroxylase Activity in Osteoblasts. Journal of Bone and Mineral Research : the Official Journal of the American Society for Bone and Mineral Research. 2015 Oct;30(10)
- Malfait, A. M., Gallily, R., Sumariwalla, P. F., Malik, A. S., Andreakos, E., Mechoulam, R., & Feldmann, M. (2000). The nonpsychoactive cannabis constituent cannabidiol is an oral anti-arthritic therapeutic in murine collagen-induced arthritis. Proceedings of the National Academy of Sciences of the United States of America, 97(17), 9561–9566.
- Philpott, H. T., O'Brien, M., & McDougall, J. J. (2017). Attenuation of early phase inflammation by cannabidiol prevents pain and nerve damage in rat osteoarthritis. Pain, 158(12), 2442–2451.
- Hammell, D. C., Zhang, L. P., Ma, F., Abshire, S. M., McIlwrath, S. L., Stinchcomb, A. L., & Westlund, K. N. (2016). Transdermal cannabidiol reduces inflammation and pain-related behaviours in a rat model of arthritis. European journal of pain (London, England), 20(6), 936–948.
- Gamble, L. J., Boesch, J. M., Frye, C. W., Schwark, W. S., Mann, S., Wolfe, L., Brown, H., Berthelsen, E. S., & Wakshlag, J. J. (2018). Pharmacokinetics, Safety, and Clinical Efficacy of Cannabidiol Treatment in Osteoarthritic Dogs. Frontiers in veterinary science, 5, 165
- Miller, R. J., & Miller, R. E. (2017). Is cannabis an effective treatment for joint pain?. Clinical and experimental rheumatology, 35 Suppl 107(5), 59–67.
- Vannabouathong, C., Zhu, M., Chang, Y., & Bhandari, M. (2021). Can Medical Cannabis Therapies be Cost-Effective in the Non-Surgical Management of Chronic Knee Pain?. Clinical medicine insights. Arthritis and musculoskeletal disorders, 14, 11795441211002492.
- Hunter, D.J., Oldfield, G., Tich, N., Messenheimer, J.A., & Sebree, T.B. (2018). Synthetic transdermal cannabidiol for the treatment of knee pain due to osteoarthritis. Osteoarthritis and Cartilage, 26.