title: The influence of different osteosynthesis configurations with locking compression plates (LCP) on stability and fracture healing after an oblique 45° angle osteotomy.
abstract: BACKGROUND
  Locking compression plates are used in various configurations with lack of detailed information on consequent bone healing.
  
  
  METHODS
  In this in vivo study in sheep 5 different applications of locking compression plate (LCP) were tested using a 45° oblique osteotomy simulating simple fracture pattern. 60 Swiss Alpine sheep where assigned to 5 different groups with 12 sheep each (Group 1: interfragmentary lag screw and an LCP fixed with standard cortex screws as neutralisation plate; Group 2: interfragmentary lag screw and LCP with locking head screws; Group 3: compression plate technique (hybrid construct); Group 4: internal fixator without fracture gap; Group 5: internal fixator with 3mm gap at the osteotomy site). One half of each group (6 sheep) was monitored for 6 weeks, and the other half (6 sheep) where followed for 12 weeks.
  
  
  METHODS
  X-rays at 3, 6, 9 and 12 weeks were performed to monitor the healing process. After sacrifice operated tibiae were tested biomechanically for nondestructive torsion and compared to the tibia of the healthy opposite side. After testing specimens were processed for microradiography, histology, histomorphometry and assessment of calcium deposition by fluorescence microscopy.
  
  
  RESULTS
  In all groups bone healing occurred without complications. Stiffness in biomechanical testing showed a tendency for higher values in G2 but results were not statistically significant. Values for G5 were significantly lower after 6 weeks, but after 12 weeks values had improved to comparable results. For all groups, except G3, stiffness values improved between 6 and 12 weeks. Histomorphometrical data demonstrate endosteal callus to be more marked in G2 at 6 weeks.
  
  
  CONCLUSIONS
  All five configurations resulted in undisturbed bone healing and are considered safe for clinical application.
authors.affiliation: Trauma Hospital Graz, Austria. michael.plecko@inode.at
authors.forename: Michael
authors.initials: M
authors.lastname: Plecko
authors.forename: Nico
authors.initials: N
authors.lastname: Lagerpusch
authors.forename: Birthe
authors.initials: B
authors.lastname: Pegel
authors.forename: Daniel
authors.initials: D
authors.lastname: Andermatt
authors.forename: Robert
authors.initials: R
authors.lastname: Frigg
authors.forename: Rudolf
authors.initials: R
authors.lastname: Koch
authors.forename: Michèle
authors.initials: M
authors.lastname: Sidler
authors.forename: Peter
authors.initials: P
authors.lastname: Kronen
authors.forename: Karina
authors.initials: K
authors.lastname: Klein
authors.forename: Katja
authors.initials: K
authors.lastname: Nuss
authors.forename: Philippe
authors.initials: P
authors.lastname: Gedet
authors.forename: Alexander
authors.initials: A
authors.lastname: Bürki
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Ferguson
authors.forename: Ulrich
authors.initials: U
authors.lastname: Stoeckle
authors.forename: Jörg A
authors.initials: JA
authors.lastname: Auer
authors.forename: Brigitte
authors.initials: B
authors.lastname: von Rechenberg
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D001860:Bone Plates; D001863:Bone Screws; D004867:Equipment Design; D005260:Female; D005593:Fracture Fixation, Internal / Q000295:instrumentation / Q000379:methods*; D017102:Fracture Healing; D010027:Osteotomy / Q000379:methods*; D012756:Sheep; D013978:Tibial Fractures / Q000503:physiopathology / Q000601:surgery*; D016474:Weight-Bearing