title: Bone morphogenetic protein 2 accelerates osteointegration and remodelling of solvent-dehydrated bone substitutes.
abstract: BACKGROUND
  lt was the purpose of this study to investigate how bone morphogenetic protein 2 (BMP-2) influences remodelling and the biomechanics of solvent-dehydrated bone in the long run. Furthermore, the early influence of this growth factor on the substitute was investigated.
  
  
  METHODS
  Using a weight-bearing animal model, solvent-dehydrated bone was implanted in the tibial head of merino sheep ( n=12) after being loaded with BMP-2 (100 microg/100 microl). At 4 weeks ( n=6) and 9 months ( n=6) after surgery, histomorphological, histomorphometrical and biomechanical investigations were performed.
  
  
  RESULTS
  At 9 months after implantation of BMP-2-loaded specimens, the bone per tissue volume was high, with levels above those of physiological cancellous bone. The amount of remaining solvent-dehydrated bone was markedly decreased, and in contrast, the amount of newly formed bone was extremely high. The specimen degradation had already occurred within the first 4 weeks after implantation, showing no further impact throughout the 9-month period. Biomechanical investigations at 9 months after implantation demonstrated a yield strength which achieved levels at least equivalent to physiological cancellous bone. BMP-2 showed no significant impact on the biomechanical properties after 4 weeks, compared to specimens prior to implantation.
  
  
  CONCLUSIONS
  BMP-2 predominantly has an impact on the early implant degradation as well as bone formation, which leads to an almost completed bone remodelling of the solvent-dehydrated specimen within the study period of 9 months.
authors.affiliation: Orthopedic Department, Städt. Krankenhaus Sindelfingen, Arthrur-Gruber-Str. 70, 71065 Sindelfingen, Germany. s.kessler@kh-sindelfingen.de
authors.forename: S
authors.initials: S
authors.lastname: Kessler
authors.forename: H E
authors.initials: HE
authors.lastname: Koepp
authors.forename: U
authors.initials: U
authors.lastname: Mayr-Wohlfart
authors.forename: A
authors.initials: A
authors.lastname: Ignatius
authors.forename: L
authors.initials: L
authors.lastname: Claes
authors.forename: W
authors.initials: W
authors.lastname: Puhl
authors.forename: K P
authors.initials: KP
authors.lastname: Günther
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D001707:Biopsy, Needle; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology*; D016723:Bone Remodeling / Q000187:drug effects*; D018786:Bone Substitutes; D016025:Bone Transplantation / Q000473:pathology*; D003890:Desiccation / Q000379:methods; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D016348:Osseointegration / Q000187:drug effects*; D012680:Sensitivity and Specificity; D012756:Sheep; D012997:Solvents; D016212:Transforming Growth Factor beta; D016474:Weight-Bearing / Q000502:physiology
chemical_list: C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D018786:Bone Substitutes; D012997:Solvents; D016212:Transforming Growth Factor beta