Which intra-articular therapy for knee osteoarthritis is known as viscosupplementation?

• A. Hyaluronic acid
• B. Corticosteroids
• C. Platelet-rich plasma
• D. Calcitonin

Answer: (A)

Viscosupplementation is the intra-articular injection approach that uses hyaluronic acid to restore the lubricating and elastic properties of synovial fluid in the knee. Hyaluronic acid is a key component of normal joint fluid, giving it viscosity and lubrication to reduce friction and shock during movement. Injecting it aims to re-create a more normal synovial environment, which can help relieve pain and improve function in knee osteoarthritis. This is distinct from corticosteroid injections, which mainly reduce inflammation; platelets-rich plasma brings growth factors for healing but does not restore joint viscosity; and calcitonin is not used for knee OA intra-articularly.