The mechanism of the keyhole lesion reassessed: An experimental approach.
The initial description of the keyhole defect was detailed as a peculiar gunshot entrance wound in the cranial vault due to firearm discharge in a tangential path. This injury may be described in two parts: a rounded section with inner table beveling and a triangular section with outer table beveling. We report a case of a gunshot skull wound "keyhole" shaped, appeared to have been made perpendicularly to the bone. Performing an experimental study on cranial bones with shots made perpendicularly to the skull approved this hypothesis, and bone injuries were then architecturally characterised using high-resolution micro computed tomography. The singular link between the tangential gunshot path and the keyhole pattern has been refuted several times, and some authors have hypothesised that there is an important role for concentric fractures that occur far away from the initial impact point of the bullet. Micro computed tomography analysis of the bone showed these keyhole defect features with a particular high description. Then, the whole pattern has a spider-web effect, and these concentric fractures could explain the keyhole pattern even in a perpendicular gunshot path.
Lille Forensic Institute (Forensic Taphonomy Unit), School of Medicine Henri Warembourg, Université de Lille, F-59000 Lille, France; Centre Hospitalier Régional Universitaire de Lille, F-59000 Lille, France; EA 4490 Physiopathologie des Maladies Osseuses Inflammatoires, School of Dentistry, Université de Lille, F-59000 Lille, France. Electronic address: yann.delannoy@univ-lille2.fr.
Yann
Y
Delannoy
Lille Forensic Institute (Forensic Taphonomy Unit), School of Medicine Henri Warembourg, Université de Lille, F-59000 Lille, France; Centre Hospitalier Régional Universitaire de Lille, F-59000 Lille, France.
Thomas
T
Colard
Lille Forensic Institute (Forensic Taphonomy Unit), School of Medicine Henri Warembourg, Université de Lille, F-59000 Lille, France; Centre Hospitalier Régional Universitaire de Lille, F-59000 Lille, France; EA 4490 Physiopathologie des Maladies Osseuses Inflammatoires, School of Dentistry, Université de Lille, F-59000 Lille, France.
Erwan
E
Le Garff
Centre Hospitalier Régional Universitaire de Lille, F-59000 Lille, France.
Sarah
S
Humez
Lille Forensic Institute (Forensic Taphonomy Unit), School of Medicine Henri Warembourg, Université de Lille, F-59000 Lille, France; Centre Hospitalier Régional Universitaire de Lille, F-59000 Lille, France.
Didier
D
Gosset
Lille Forensic Institute (Forensic Taphonomy Unit), School of Medicine Henri Warembourg, Université de Lille, F-59000 Lille, France; Centre Hospitalier Régional Universitaire de Lille, F-59000 Lille, France.
Valéry
V
Hedouin
D000368:Aged; D002102:Cadaver; D044709:Forensic Ballistics / Q000379:methods*; D049429:Forensic Pathology; D020197:Head Injuries, Penetrating / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D012887:Skull Fractures / Q000000981:diagnostic imaging / Q000473:pathology*; D014948:Wounds, Gunshot / Q000000981:diagnostic imaging / Q000473:pathology*; D055114:X-Ray Microtomography
Biomechanics; Forensic anthropology; Gunshot wounds; Keyhole defect; Micro computed tomography; Skull fractures