title: BMP-2-based repair of large-scale calvarial defects in an experimental model: regenerative surgery in cranioplasty.
abstract: Pediatric craniofacial surgery is complicated by a shortage of autologous bone. Children between 2 and 10 years of age are especially problematic, as the dura has lost its potential to spontaneously heal large calvarial defects by approximately 2 years of age, and split calvarial grafts are often unavailable because of the underdeveloped diploic space until later childhood. We demonstrate the efficacy of a BMP-2-based system in repairing large-scale cranial defects in a rabbit model. Calvarial defects, 15 mm, were created in 18 adult New Zealand white rabbits, treated as follows: group 1, no repair (n = 6); group 2, absorbable collagen sponge (ACS) (n = 4); and group 3, recombinant human bone morphogenetic protein 2 delivered on ACS (rhBMP-2/ACS) (n = 8). Bone regeneration 6 weeks postoperatively was evaluated by 2- and 3-dimensional standard computed tomography, micro-computed tomography. Analysis of variance was performed using SPSS. The generated bone was also evaluated histologically. After 6 weeks, group 1 defects were on average 32.8% (SD, 8.8%) ossified. Group 2 defects were on average 34.4% (SD, 17.1%) ossified. Defects in group 3 were on average 96.9% (SD, 3.7%) ossified, significantly (P < 0.005) more than the defects in groups 1 and 2. rhBMP-2-induced bone was histologically and radiographically consistent with native bone. This study demonstrates the efficacy of rhBMP-2/ACS for the repair of calvarial defects in the rabbit model. rhBMP-2/ACS may offer a viable treatment option for craniofacial surgeons facing a shortage of bone, with the potential to replace autologous bone grafts and render their attendant morbidities obsolete.
authors.affiliation: Division of Plastic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
authors.forename: Darren M
authors.initials: DM
authors.lastname: Smith
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: Afifi
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Cooper
authors.forename: Mark P
authors.initials: MP
authors.lastname: Mooney
authors.forename: Kacey G
authors.initials: KG
authors.lastname: Marra
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Losee
mesh_terms: D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000494:pharmacology*; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology; D001861:Bone Regeneration / Q000187:drug effects*; D003094:Collagen / Q000494:pharmacology; D003399:Craniotomy; D005781:Gelatin Sponge, Absorbable; D006801:Humans; D023421:Models, Animal; D011817:Rabbits; D011994:Recombinant Proteins / Q000494:pharmacology; D012886:Skull / Q000601:surgery*; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D055114:X-Ray Microtomography
chemical_list: D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2; D003094:Collagen