Recombinant human BMP-2 enhances the effects of materials used for reconstruction of large cranial defects.
OBJECTIVE
Cranial defect reconstruction presents 2 challenges: induction of new bone formation, and providing structural support during the healing process. This study compares quantity and quality of new bone formation based on various materials and support frameworks.


METHODS
Eighteen dogs underwent surgical removal of a significant portion of their cranial vault. Demineralized bone matrix was used to fill the defect in all animals. In 9 dogs, recombinant human bone morphogenetic protein-2 (rhBMP-2) was added, while the other 9 served as the non-rhBMP-2 group. In each group, 3 animals were fixed with cobalt chrome plates, 3 with adding platelet-rich plasma, and 3 fixed with a Lactosorb (Walter Lorenz Surgical, Inc, Jacksonville, FL) resorbable mesh. Necropsy was done at 12 weeks postoperative. Histomorphometry, density, and mechanical properties of the regenerate were analyzed.


RESULTS
The non-rhBMP-2 groups showed minimal substitution of demineralized bone matrix with new bone, while only sporadic remnants of demineralized bone matrix were present in the rhBMP-2 groups. The defect showed more new bone formation (P < .001) and density (P < .001) in the rhBMP-2 groups by Kruskal-Wallis test. The area of new bone was not significantly different among the rhBMP-2 subgroups. The resorbable mesh struts showed no sign of bone invasion or substitution. In the non-rhBMP-2 resorbable mesh group, demineralized bone matrix almost totally disintegrated without replacement by new bone.


CONCLUSIONS
The addition of rhBMP-2 to demineralized bone matrix accelerated new bone formation in large cranial defects, regardless of the supporting framework or the addition of platelet-rich plasma. The use of a resorbable mesh in such defects is advisable only if rhBMP-2 is added.
Elsalanty
Mohammed E
ME
Department of Oral Biology and Maxillofacial Pathology, School of Dentistry, Medical School of Georgia, Augusta, GA, USA.
Por
Yong-Chen
YC
Genecov
David G
DG
Salyer
Kenneth E
KE
Wang
Qian
Q
Barcelo
C R
CR
Troxler
Karen
K
Gendler
El
E
Opperman
Lynne A
LA
D000818:Animals; D001672:Biocompatible Materials; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000627:therapeutic use*; D001860:Bone Plates; D001861:Bone Regeneration / Q000187:drug effects*; D018786:Bone Substitutes / Q000737:chemistry / Q000627:therapeutic use*; D016025:Bone Transplantation / Q000000981:diagnostic imaging / Q000379:methods*; D003035:Cobalt; D004285:Dogs; D006801:Humans; D008297:Male; D053657:Platelet-Rich Plasma; D012886:Skull / Q000000981:diagnostic imaging / Q000601:surgery*; D013526:Surgical Mesh; D016212:Transforming Growth Factor beta / Q000627:therapeutic use*; D014463:Ultrasonography
C525718:BMP2 protein, human; D001672:Biocompatible Materials; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D018786:Bone Substitutes; D016212:Transforming Growth Factor beta; D003035:Cobalt