A Pilot Trial of Acupuncture for Knee Osteoarthritis With Differential Functional Status of Acupoints

Inclusion Criteria: * Eligible patients are those aged 40 years or older who are diagnosed with KOA and have signed the informed consent. * The diagnosis of KOA will follow the diagnostic criteria according to the Chinese Guidelines for the Medical Management of Osteoarthritis: * refractory knee pain for most days in the last month; * joint space narrowing, sclerosis or cystic change in subchondral bone (as indicated by X-ray); * laboratory examinations of arthritis: clear and viscous synovial fluid (≥2 times) and white blood cell count \< 2000/mm3; * age 40 years or older; * morning stiffness continues less than 30 minutes; * bone sound exists when joints was taking flexion and/or extension. A person is confirmed to be diagnosed with KOA if meeting the either of the three criteria set: (1 and 2), or (1,3 and 5), or (1,4,5 and 6). Exclusion Criteria: Patients will be excluded if they: * Can not adhere to the study protocol in the future 6 months; * Are diagnosed with conditions leading to skeletal disorders, such as tuberculosis, tumors or rheumatism of knee/bone joint, rheumatoid arthritis; * Have sprain or other trauma; * Are unable to walk properly due to foot deformity or pain; * Are present with mental disorders; * Have comorbidities including severe cardiovascular disease, liver or kidney impairment, immunodeficiency, diabetes mellitus or blood disorder; * Females who are pregnant or lactating; * Were using physiotherapy treatments for osteoarthritis knee pain; * Had used intra-articular injection of glucocorticoid or viscosupplementation in the past 6 months; * Received knee-replacement surgery; * Were participating or had participated in the other clinical trials.