Comparison Between Four Types of Single Dose Hyaluronic Acid Injection in Patients With Knee Osteoarthritis

Study design: Allocation: Randomized. Endpoint Classification: Comparative Study. Intervention model: Parallel Assignment. Masking: Double Blind (Subject, Assessed) Primary purpose: Comparison. Official Title: Intra-articular hyaluronic acid knee injection: randomized control trail. Primary outcome measures: * Lower extremity functional scale * Visual analogue scale * Range of motion * Kellgren and Lawrence class grade Estimated enrollment: 100 Study start date: December 2012 Estimated study completion date: June 2013 Estimated primary completion date: December 2013