Managing knee ostheoarthritis: efficacy of hyaluronic acid injections

Osteoarthritis (OA) is the most common form of chro nic arthritis worldwide. The etiology of pain in os teoarthritis is multifactoral, and includes mechanical and inflammatory processes. The use of intra-articular viscosupplementation in the nonoperative manage ment of patients with osteoarthritis has become quite popular. Recent clinical data have demonstrated that the anti-inflammatory and chondroprotective actions of hyaluronic acid viscosupplementation reduce pain, from 4 to 14 weeks after injection, while improving pa tient function. Viscosupplements are comparable in ef ficacy to systemic forms of active intervention, with more local reactions but fewer systemic adverse events, and hyaluronic acid has more prolonged effects than IA corticosteroids. Although several randomized con trolled trials have established the efficacy of this treat ment modality, additional high quality randomized control studies with appropriate comparison are still required to clearly define the role of intra-articular hya luronic acid injections in the treatment of osteoarthri tis. We review the basic science and development of viscosupplementation and discuss the mounting evi dence in support of its efficacy and safety profile.