Pronator Sign - Orthopaedia

Location	Wrist
Diagnosis	Wrist Fracture
Discussion	A. Normal pronator fat pad. B. Displaced pronator fat pad. Lateral wrist x-ray, a reveals abnormal bulging of a fat plane adjacent to an area of underlying osseous injury. The ventral bulging of the fat plane overlying the pronator quadratus muscle has been coined the "pronator sign." Although it typically means underlying fracture is present, it may also be seen in simple soft-tissue injury of the same region. It is a good sign and should alert the radiologist of possible fracture when present.
Reference	Zimmers TE: Fat plane radiological signs in wrist and elbow trauma. Am J Emerg Med 1984 Nov;2(6):526-32.