Synvisc ® Hylan GF 20 is a preparation intended for use in periodic replacement and supplementation of synovial fluid. Each 2 ml pre-filled syringe contains 16 mg of hylan polymers. Hylans are cross-linked derivatives of hyaluronan - a natural linear polysaccharide complex belonging to the group of glycosaminoglycans. The preparation contains hylan A and hylan B in a buffered, physiological solution of NaCl. The active substance of the preparation is hylan A with an average molecular weight of 6,000,000. The solution also contains hylan B in the form of a hydrated gel. When to use Synvisc ® Hylan GF 20 16 mg/2 ml? Synvisc ® Hylan GF 20 prefilled syringes are a medical device used: to periodically replace and supplement the synovial fluid, in patients in various stages of degenerative joint changes, in the treatment of pain associated with osteoarthritis. Synvisc ® is most effective in patients who actively and regularly use the affected joint. It produces a therapeutic effect through viscosupplementation - a process by which the physiological and rheological state of tissues affected by joint inflammation is restored. The solution has rheological properties similar to normal synovial fluid in young people. The intra-articular administration of the preparation aims to improve the mechanical properties of the inflamed synovial fluid. By restoring the rheological properties of the fluid to normal, the preparation covers and protects the tissue surfaces, fills the intercellular space of the soft connective tissue of the joint, thus providing protection to the cells and fibrous elements of the extracellular matrix. By also reducing the degree of excitability of pain receptors at rest and during movement, it reduces pain and restores proper mobility in the joint.