Inclusion Criteria:  Patients of age 30 years and above Radiographical diagnosis of knee OA - ie narrowing of joint space, presence of osteophytes, possible sclerosis and subchondral cysts History of chronic pain in knee or knee swelling for at least 3 months Ability of patients to provide informed consent  Exclusion Criteria:  Concurrent complementary and alternative medicine (CAM) treatments e.g. acupuncture Inflammatory diseases / infection / fracture / trauma Malignancies Pregnant or lactating females Consistent use of NSAIDs within 48 hours of procedure Corticosteroid injection at treatment site within 1 month Systemic use of corticosteroids within 2 weeks Tobacco use (For patients receiving PRP-HA injection only): Hemoglobin <10 g/dL and platelets <150,000/mm3