title: Ballistics for neurosurgeons: Effects of firearms of customized cranioplasty implants.
abstract: BACKGROUND
  There are about 33,000 deaths caused by gunshot wounds in the USA each year. Probably half of these deaths result from head wounds. Among US Army soldiers, 17% of all ballistic injuries are head wounds. This means that, even in those protected by ballistic helmets, gunshot injuries to the head represent a danger. The aim of this study was to examine the effects of shelling of computer-aided designed (CAD) cranioplasty implants made of two different materials.
  
  
  METHODS
  An experimental model was developed in an indoor gun range. CAD cranioplasties with a material thickness of 2-6 mm, made of titanium or PEEK-OPTIMA(®) were fixed in a watermelon and shot at with a .222 Remington rifle at a distance of 30 m distance, a .30-06 Springfield rifle at a distance of 30 m, a Luger 9 mm pistol at a distance of 8 m, or a .375 Magnum revolver at a distance of 8 m. The CAD cranioplasties were subsequently inspected for ballistic effects by a neurosurgeon.
  
  
  RESULTS
  Titanium CAD cranioplasty implants resisted shots from the 9 mm Luger pistol and were penetrated by both the .222 Remington and the .30-06 Springfield rifle. Shooting with the .357 Magnum revolver resulted in the titanium implant bursting. PEEK-OPTIMA(®) implants did not resist bullets shot from any weapon. The implants burst on shooting with the 9 mm Luger pistol, the .222 Remington, the .30-06 Springfield rifle, and the .357 Magnum revolver.
  
  
  CONCLUSIONS
  Titanium CAD cranioplasty implants may offer protection from ballistic injuries caused by small caliber weapons fired at short distances. This could provide a life-saving advantage in civilian as well as military combat situations.
authors.affiliation: Department of Neurosurgery, Unfallkrankenhaus Berlin, Berlin, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Lemcke
authors.forename: Rainer
authors.initials: R
authors.lastname: Löser
authors.forename: Andreas
authors.initials: A
authors.lastname: Telm
authors.forename: Ullrich
authors.initials: U
authors.lastname: Meier
keywords: Ballistic injuries; bullet resistance; computer-aided designed customized cranioplasty implants