The fat pad sign and the supinator fat line (SFL) are valuable diagnostic aids in the evaluation of bony cubital injuries. A total of 377 lateral X-rays of the elbow joint-including 121 fractures--were investigated. The supinator fat line exhibited bar-like and bird-like configurations in 55.9% and 41.8% of healthy test subjects, respectively. In the presence of a fracture, a wavy configuration, directed downwards from, or running parallel to, the upper edge of the radius, was seen in 95% of the cases. If in the event of an injury to the elbow a wavy configuration is seen in association with a positive anterior and/or posterior fat pad sign, bony involvement of the joint-forming elements may justifiably be suspected.
