CBD Knee Osteoarthritis Study

Osteoarthritis of the knee is a common cause of pain in the US. The currently available medicines for knee osteoarthritis sometimes are not effective at relieving the pain or have unacceptable side effects. Thus, alternate pain relieving treatments are needed. CBD, an active chemical from the hemp derived cannabis sativa plant, has received a lot of attention for its potential pain relieving properties, but there has been limited research to find out if topically applied CBD can decrease pain from knee osteoarthritis. CBD lacks the psychoactive effects seen with marijuana use, because it does not contain THC which is responsible for those effects in marijuana. It is legal to use CBD in the State of Tennessee (site of study). The CBD Knee Study is sponsored by the University of Tennessee Health Science Center and is a collaborative effort between doctors at UT and Campbell Clinic. In the CBD Knee Study, the investigators are examining whether topically applied CBD dissolved in Castor Oil will relieve knee pain in persons with knee osteoarthritis. Persons who take part in the study would need to come for study visits, fill out questionnaires about their health and knee pain, and would be asked to use the topical study oil on their knees. Taking part in the CBD Knee Study is voluntary.

Inclusion Criteria: 1. Knee OA (grade 2-3 as measured by the Kellgren-Lawrence Classification) 2. OA knee pain on the Visual Analog Pain Scale \> 4 in either knee 3. Receiving treatment at one of the eight Campbell Clinic Orthopaedics locations Exclusion Criteria: 1. Other forms of arthritis such as psoriatic arthritis or rheumatoid arthritis due to different sources of inflammation in these conditions 2. Allergies to CBD or Castor Oil 3. Current opioid use 4. BMI of over 40 5. Those who cannot walk without an assistance device (e.g., walker) 6. Those who are currently on knee injections (i.e. cortisol or hyaluronic acid gel) for knee pain 7. Patients scheduled for a knee replacement in the next 3-6 months 8. Active cannabis or CBD use 9. Alcohol consumption \> 21 alcoholic drinks each week 10. Active pregnancy, nursing, or actively planning a pregnancy 11. Active chronic liver or renal disease 12. Active depression/suicidality 13. Medications that interact with CBD in the liver that cannot be discontinued 14. Discretion of the Multiple Principal Investigators for concerns regarding noncompliance with the study intervention.