title: Repair of critical long bone defects using frozen bone allografts coated with an rhBMP-2-retaining paste.
abstract: BACKGROUND
  Massive frozen stocked allogeneic bone grafts are often used to reconstruct large bone defects caused by trauma or tumor resections. However, the long-term failure rate of such massive allografts was reported to be 25% because of infection, fracture, and nonunion. In this study, we evaluated the ability of a recombinant human bone morphogenetic protein (rhBMP)-2-retaining paste to promote the osteogenic potential of frozen stocked allogeneic bone grafts to repair intercalated femoral shaft defects in a rat model.
  
  
  METHODS
  After confirming the transplantation intolerance between two rat strains (Wistar and Lewis) by skin transplantation from Lewis rats to Wistar rats, an 8-mm-long bone segment was removed from the Wistar rats, and a frozen stocked allograft coated with the rhBMP-2-retaining paste from the Lewis rats was placed into the defect and subjected to intramedullary fixation with an 18-gauge injection needle pin. The allografted femurs were evaluated by radiographic, histologic, and biomechanical examinations at specified time points.
  
  
  RESULTS
  The results revealed successful repair of critical-size cortical bone defects by implanting frozen stocked allografts coated with the rhBMP-2-retaining synthetic biodegradable carrier paste from an immunologically intolerant host.
  
  
  CONCLUSIONS
  This experimental study suggest that allogeneic bone grafting in combination with rhBMP-2 and its local delivery system may represent an innovative approach to the reconstruction of bone defects.
authors.affiliation: Department of Orthopedic Surgery, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-Machi, Abeno-Ku, Osaka, 545-8585, Japan. hiroyuki19780728@yahoo.co.jp
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yasuda
authors.forename: Koichi
authors.initials: K
authors.lastname: Yano
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Wakitani
authors.forename: Tomiya
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nakamura
authors.forename: Kunio
authors.initials: K
authors.lastname: Takaoka
mesh_terms: D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000008:administration & dosage*; D016025:Bone Transplantation / Q000379:methods*; D005269:Femur / Q000601:surgery*; D005615:Freezing; D008297:Male; D051381:Rats; D011917:Rats, Inbred Lew; D011994:Recombinant Proteins / Q000008:administration & dosage; D016212:Transforming Growth Factor beta / Q000008:administration & dosage*
chemical_list: D055396:Bone Morphogenetic Protein 2; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2