Lipohaemarthrosis seen on plain radiographs is unusual in the glenohumeral joint, although in one series it was seen in 25% of cases. It was first reported in 1962 (compare with 1929 for knee lipohaemarthrosis). It is only seen on erect views. Lipohaemarthroses have also been described in elbow and hip joints.
Note that a fluid-fluid level may be seen in a simple haemarthrosis on MRI. The upper fluid must show magnetic characteristics of fat (e.g. drop signal on fat-sat sequences) before you can call it a lipohaemarthrosis.
Image and description courtesy of: Dr Laughlin Dawes