Synovial fluid viscosity augmentation

Synovial fluid is a complex biological lubricant found in synovial joints, responsible for reducing friction and facilitating smooth joint movement. The term "Synovial fluid viscosity augmentation" does not refer to a specific molecule or receptor but rather describes a therapeutic or functional goal related to increasing the viscosity of synovial fluid (SF) within joints. Its primary components responsible for its viscoelastic and lubricating properties are Hyaluronic acid (HA) and Proteoglycan 4 (PRG4, also known as lubricin), along with other components such as proteinases, collagenases, fibronectin, albumin, and phospholipids. The rheological behavior of SF changes under different shear rates: at low velocity gradients SF exhibits high viscosity which decreases with increased shear rate—a property important for facilitating smooth mechanical movement while protecting cartilage from wear. This concept relates more closely to therapeutic strategies aimed at improving the physical characteristics—especially viscosity—of synovial fluid through supplementation or regeneration rather than being an individual biochemical target like receptors or enzymes. Alterations in SF composition and decreased viscosity are implicated in osteoarthritis, rheumatoid arthritis, and other joint disorders involving trauma or aging, leading to pain and impaired mobility.

Other names

ViscosupplementationSynovial lubrication enhancement

Restoration or increase of hyaluronic acid (HA) concentration and quality in the joint space to restore viscoelasticity, improve boundary lubrication via interaction with PRG4/lubricin, and reduce frictional forces on cartilage surfaces.