title: Biomechanical comparison of the fixation after curved periacetabular osteotomy using titanium and bioabsorbable screws.
abstract: OBJECTIVE
  We performed curved periacetabular osteotomy, a modification of the Bernese periacetabular osteotomy, to treat hip dysplasia. The purpose of our study was to compare the biomechanical stability of acetabular fragments fixed in place with 3 titanium screws, or with 2 or 3 bioabsorbable screws composed of particulate resorbable uncalcined hydroxyapatite (HA) and poly-L-lactic acid (PLLA) termed HA/PLLA screws.
  
  
  METHODS
  Curved periacetabular osteotomy was performed on 24 composite model hemipelves. Three groups of 8 specimens were affixed with 1) 3 titanium screws, 2) 2 HA/PLLA screws, or 3) 3 HA/PLLA screws. After fixation, the hemipelves were biomechanically attested with simulated push-off phase of the gait cycle using a servohydraulic material testing system.
  
  
  RESULTS
  The average failure loads were not significantly different among the3 groups tested. However, the group repaired with 3 HA/PLLA screws showed significantly greater stiffness than the other groups.
  
  
  CONCLUSIONS
  All 3 fixation methods provided sufficient stability to allow for early partial weight-bearing after surgery. The use of 3 HA/PLLA screws provided significantly greater stiffness for acetabular fragment fixation.
authors: 1 Department of Orthopaedic Surgery, Faculty of Medicine, Fukuoka University, Fukuoka - Japan.
authors: Nobuhiro
authors: N
authors: Kashima
authors: Kei
authors: K
authors: Shiramizu
authors: Yoshinari
authors: Y
authors: Nakamura
authors: Shigeaki
authors: S
authors: Moriyama
authors: Masatoshi
authors: M
authors: Naito
mesh_terms: D020341:Absorbable Implants; D000077:Acetabulum / Q000601:surgery*; D001696:Biomechanical Phenomena; D001863:Bone Screws; D017886:Durapatite; D006801:Humans; D008422:Materials Testing; D008953:Models, Anatomic; D010027:Osteotomy / Q000295:instrumentation* / Q000379:methods; D013314:Stress, Mechanical; D014025:Titanium
chemical_list: D017886:Durapatite; D014025:Titanium