Synovial fluid, which is viscoelastic due to the presence of hyaluronic acid, is found in all synovial joints, particularly the large weight-bearing joints, where it ensures normal, painless movement due to its lubricating and shock-absorbing properties, and is also responsible for the nutrition of the cartilage.

Supplementing this synovial fluid with intra-articular injections of highly purified hyaluronic acid can improve the viscoelastic properties of the synovial fluid. This improves its lubricating and shock-absorbing functions and reduces mechanical overload of the joint. As a rule, this results in a decrease in pain and an improvement in joint mobility, which may last for several months after a treatment cycle of 3 intra-articular injections.