Musculoskeletal ImagingSynovial fluid
a clear viscous, slightly alkaline fluid present in healthy joints but whose exact composition, viscosity, volume and colour vary somewhat from joint to joint. The
synovial fluid aids in nutrition of the adjacent
cartilage and disc and provides lubrication to joint surfaces.
In crystal deposition diseases, crystals of various composition may be found in the synovial fluid. In some cases acute and chronic inflammatory changes may occur. Similarly, particles, cell fragments, fibrous tissue and microorganisms may also occur as a consequence of wear and tear on the articular surface.
Subchondral cysts may form as a result of intrusion of synovial fluid into subchondral bone in osteoarthritis.
In lipohaemarthrosis a haemorrhagic effusion with fat droplets and, sometimes, spicules of bone marrow may occur and is usually a reliable indicator of fracture, but may also be seen in some patients with significant cartilage or ligament injury.
DR