Fat plane radiological signs in wrist and elbow trauma.

With most elbow or wrist injuries, if fractures are not evident, they are probably nonexistent. But in a small percentage of cases, these signs serve to lower diagnostic thresholds. Of the four fat plane signs reviewed, the posterior fat pad sign and the navicular fat stripe seem to be more valuable than the supinator and pronator quadratus signs. However, each is useful in its own way. Although the clinical appearance of the extremity may dictate the same initial treatment whether or not a fracture is found, early identification of more subtle fractures will avoid delay of definitive treatment and provide a better estimation of healing time. None of these signs alone is completely reliable; they should be used as adjuncts in fracture diagnosis. Finally, no sign is specific to one type of fracture, although one or two types of occult fractures are most commonly identified on supplementary views when such signs are positive.