Comparison of different radiography systems in an experimental study for detection of forearm fractures and evaluation of the Müller-AO and Frykman classification for distal radius fractures.
OBJECTIVE
We sought to compare the diagnostic performance of screen-film radiography, storage-phosphor radiography, and a flat-panel detector system in detecting forearm fractures and to classify distal radius fractures according to the Müller-AO and Frykman classifications compared with the true extent, depicted by anatomic preparation.


METHODS
A total of 71 cadaver arms were fractured in a material testing machine creating different fractures of the radius and ulna as well as of the carpal bones. Radiographs of the complete forearm were evaluated by 3 radiologists, and anatomic preparation was used as standard of reference in a receiver operating curve analysis.


RESULTS
The highest diagnostic performance was obtained for the detection of distal radius fractures with area under the receiver operating curve (AUC) values of 0.959 for screen-film radiography, 0.966 for storage-phosphor radiography, and 0.971 for the flat-panel detector system (P > 0.05). Exact classification was slightly better for the Frykman (kappa values of 0.457-0.478) compared with the Müller-AO classification (kappa values of 0.404-0.447), but agreement can be considered as moderate for both classifications.


CONCLUSIONS
The 3 imaging systems showed a comparable diagnostic performance in detecting forearm fractures. A high diagnostic performance was demonstrated for distal radius fractures and conventional radiography can be routinely performed for fracture detection. However, compared with anatomic preparation, depiction of the true extent of distal radius fractures was limited and the severity of distal radius fractures tends to be underestimated.
Metz
Stephan
S
Department of Diagnostic Radiology, Technical University of Munich, Ismaninger Strasse 22, 81675 Munich, Germany. smetz@roe.med.tu-muenchen.de
Kuhn
Volker
V
Kettler
Mark
M
Hudelmaier
Martin
M
Bonel
Harald M
HM
Waldt
Simone
S
Hollweck
Regina
R
Renger
Bernhard
B
Rummeny
Ernst J
EJ
Link
Thomas M
TM
D019540:Area Under Curve; D002102:Cadaver; D002348:Carpal Bones / Q000000981:diagnostic imaging; D006801:Humans; D012372:ROC Curve; D011859:Radiography / Q000295:instrumentation* / Q000379:methods*; D011885:Radius Fractures / Q000145:classification* / Q000000981:diagnostic imaging*; D014458:Ulna Fractures / Q000000981:diagnostic imaging*; D014963:X-Ray Intensifying Screens