What are the characteristics of fluid collected from lipohemarthrosis?

Fluid collected from lipohemarthrosis is characterized by an oily and greasy appearance due to the presence of fat, which indicates that there is both blood and fat in the joint space. Lipohemarthrosis typically occurs after a traumatic injury to a joint, particularly the knee, where there is a fracture that allows fat from the bone marrow to leak into the joint. The combination of blood and fat causes this distinct appearance, setting it apart from other types of joint effusions.

The presence of blood contributes to the cloudiness of the fluid, but the significant element here is the fat, which gives it that specific greasy quality. This characteristic fluid has diagnostic importance, as it helps differentiate lipohemarthrosis from other conditions that may cause joint swelling or effusion.