Ultrasonic demonstration of the elbow fat pads

Elevation of the fat pads around the elbow joint is a well recognised radiological sign of a joint effusion which may be due to trauma or other inflammatory process. There are occasions when plain radiographs fail to demonstrate this sign. A case is reported in which elevation of the posterior fat pad and an elbow joint effusion were demonstrated ultrasonically. Comparative ultrasound examination of the normal elbow in this patient and examination of 40 normal elbows, in adults and children, consistently demonstrated the normal anterior and posterior fat pads except in one patient aged 4 days where the fat pads could not be clearly seen. The normal ultrasonic appearances are described. Ultrasound examination may be useful in patients where plain radiographs have failed to demonstrate the position of the fat pads.