Development of titanium fixation screw for hydroxyapatite osteosynthesis (APACERAM).
BACKGROUND
Cranioplasty using custom-made HAP ceramic implants is a common procedure for skull defects. However, miniplate fixation using commercially available screws to stabilize the HAP flap is associated with several problems due to characteristic brittleness. The authors have thus developed a suitable screw for this procedure.


METHODS
Hydroxyapatite blocks (porosity, 40%; thickness, 5 mm) were prepared. Holes were created using a phi 1.4-mm drill. Five types of screw were evaluated for HAP condition after insertion, fixation strength on pull-out test, and fasten plate strength based on maximum torque.


RESULTS
Based on this evaluation, the most effective screws were cylindrical style in shape, 4.8 mm in effective length, phi 1.6 mm in effective diameter, and 0.2 mm in edge height.


CONCLUSIONS
A novel screw with high fixation potential for the miniplate technique was developed in this study.
Tanaka
Yoshihide
Y
Department of Neurosurgery, Yokosuka Kyousai Hospital, Yokosuka, Kanagawa 2380011, Japan. yoshihidet@aol.com
D001672:Biocompatible Materials; D001860:Bone Plates; D001863:Bone Screws; D003399:Craniotomy / Q000295:instrumentation*; D017886:Durapatite; D004867:Equipment Design; D005593:Fracture Fixation, Internal / Q000295:instrumentation*; D006801:Humans; D008422:Materials Testing; D008954:Models, Biological; D016062:Porosity; D013718:Tensile Strength; D014025:Titanium
D001672:Biocompatible Materials; D017886:Durapatite; D014025:Titanium