Cannabinoid Profile Investigation of Vapourized Cannabis in Patients With Osteoarthritis of the Knee

Primary Objective: - To determine the analgesic dose-response characteristics of vapourized cannabinoids with varying degrees of delta-9-tetrahydrocannabiol (THC)/ Cannabidiol (CBD) ratios. Secondary Objectives: * To compare functional changes and patient preferences of different cannabinoid (THC, CBD) profiles in patients with OA (Osteoarthritis); * To describe the Pharmacokinetics (PK) of vapourized cannabis of differing cannabinoid profiles in patients with OA; * To explore the short term safety of vapourized cannabis with different cannabinoid profiles. * To describe the incidence and severity of psychoactive events.