The Safety and Efficacy of Single IA-HA Injection in Patients With Knee Osteoarthritis: A Prospective Study

Inclusion Criteria: * Patients Age should not be less than 18 years. * Patients must be able to understand and follow the study procedures and must provide written informed consent. * Radiologically Grade II or III osteoarthritis of knee according to the Kellgren and Lawrence classification. * Mild to moderate documented diagnosis of knee osteoarthritis that fulfill the ACR (American College of Rheumatology) criteria. * Patients with consistent symptoms (joint pain, crepitus, swelling, effusion alone or combination of these symptoms) of knee osteoarthritis for at least 3 months prior to screening. If bilateral knee pain is present, the more painful knee will be selected. * Patients who are willing to discontinue all non-steroidal anti-inflammatory drugs (NSAIDs) or other analgesic medication taken for any condition, including their knee pain. However patients will be allowed to use only acetaminophen or aspirin as a rescue pain medication during the study period. The patients must abstain from medication use 24 hours prior to any study visit. Exclusion Criteria: * Patients with secondary osteoarthritis of the knee according to ACR criteria. * Pregnant or lactating women, and women of childbearing potential not willing to use adequate contraception. * Patients unable to stay in the study for 6 months, non- cooperating, not able to understand * Patients having previously undergone surgery on target knee, including arthroscopy. * Patients with neurological deficit in the lower extremities, with primary inflammatory joint disease, intra-articular tumours. * Any severe systemic disease(s). * Any significant osteoarthritis symptoms in other joints apart from the target knee which may require pharmacological treatment during the study. * Patients who have received intra-articular hyaluronic acid within the previous 6 month and/or intra-articular steroids or articular lavage in the target knee within the previous 3 months prior to their inclusion in the study. * Administration of glucosamine sulphate, chondroitin sulphate and diacerein within the 3 months prior to their inclusion in the study. * History of allergy or hypersensitivity to hyaluronic acid. * Participation in any clinical study in the last 3 months and any surgery scheduled in the next 8 months that can affect directly the result of the present study.