"It is well known that fat floats on water as it is less dense. The fatty marrow separates from the water-based blood and layers above it, forming a fat-fluid level (also known as the FBI sign). This can be seen on all modalities."
"It is important to remember that up to 64% of tibial plateau fractures do not have an x-ray visible lipohaemarthrosis, but rather a simple haemarthrosis 1; thus absence of the finding does not exclude an intra-articular fracture."
Expected headings
"CT and MRI"
"Lipohaemarthrosis results from an intra-articular fracture with escape of fat and blood from the bone marrow into the joint, and is most frequently seen in the knee, associated with a tibial plateau fracture or distal femoral fracture; rarely a patellar fracture. They have also been described in hip, shoulder, elbow and wrist fractures 1,2,4."
"It is important to remember that up to 64% of tibial plateau fractures do not have an x-ray visible lipohaemarthrosis, but rather a simple haemarthrosis 1; thus absence of the finding does not exclude an intra-articular fracture."
"suprapatellar fat pad: usually not a horizontal line; does not change on repositioning or agitation of the joint fluid"
"Lipohaemarthrosis results from an intra-articular fracture with escape of fat and blood from the bone marrow into the joint, and is most frequently seen in the knee, associated with a tibial plateau fracture or distal femoral fracture; rarely a patellar fracture. They have also been described in hip, shoulder, elbow and wrist fractures 1,2,4."