Scaphoid and pronator fat stripes are unreliable soft tissue signs in the detection of radiographically occult fractures.
OBJECTIVE
To determine the clinical value of scaphoid and pronator fat stripes in identifying occult underlying scaphoid and distal radius fractures, respectively.


METHODS
In our department, all patients with clinically suspected scaphoid fractures and normal scaphoid series of radiographs undergo magnetic resonance imaging (MRI) of the wrist. We selected 50 cases with unequivocal MRI evidence of scaphoid fracture, 50 cases with distal radius fracture and 50 cases with no MRI evidence of bony injury. All 150 initial plain radiographs were examined retrospectively in random order without knowledge of the MRI findings and the scaphoid and pronator fat stripes scrutinized.


RESULTS
The scaphoid fat stripe was abnormal in only 25 cases (50%) with confirmed scaphoid fracture on MRI. The pronator fat stripe was abnormal in 13 cases (26%) with confirmed distal radius fracture. In the 50 cases with no MRI evidence of bony injury, the scaphoid fat stripe and pronator fat stripe were abnormal in 25 (50%) and 15 (30%) cases, respectively. The sensitivity and specificity for an abnormal scaphoid fat stripe was 50%. The sensitivity and specificity for an abnormal pronator fat stripe was 26 and 70%, respectively.


CONCLUSIONS
Scaphoid and pronator fat stripes are poor predictors of the presence or absence of underlying occult fractures.
Annamalai
G
G
Department of Radiology, Western Infirmary, North Glasgow Hospitals NHS Trust, Glasgow, UK.
Raby
N
N
D000273:Adipose Tissue; D005188:False Negative Reactions; D005596:Fractures, Closed / Q000175:diagnosis* / Q000000981:diagnostic imaging; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000592:standards; D011859:Radiography; D012189:Retrospective Studies; D021361:Scaphoid Bone / Q000000981:diagnostic imaging / Q000293:injuries*; D012680:Sensitivity and Specificity; D017695:Soft Tissue Injuries / Q000175:diagnosis* / Q000000981:diagnostic imaging