title: Locally delivered rhBMP-2 enhances bone ingrowth and gap healing in a canine model.
abstract: The purpose of the present study was to determine if recombinant human bone morphogenetic protein-2 (rhBMP-2) enhances bone ingrowth into porous-coated implants and gap healing around the implants. In the presence of a 3-mm gap between the implant and host bone, porous-coated implants were placed bilaterally for four weeks in the proximal humeri of skeletally mature, adult male dogs. In three treatment groups, the test implant was treated with HA/TCP and rhBMP-2 in buffer at a dose of 100 microg/implant (n=5), 400 microg/implant (n=6), or 800 microg/implant (n=5) and placed in the left humerus. In these same animals, an internal control implant was treated only with HA/TCP and buffer and placed in the right humerus. These groups were compared with a previously reported external control group of seven animals in which no growth factor was delivered [J. Orthop. Res. 19 (2001) 85]. The BMP treated implants in the two lower dose groups had significantly more bone ingrowth than the external controls with the greatest effect in the 100 g/implant group (a 3.5-fold increase over the external control, p=0.008). All three dose groups had significantly more bone formation in the 3-mm gap surrounding the BMP treated implants than the external controls with the greatest effect in the 800 microg group (2.9-fold increase, p<0.001). Thus, application of rhBMP-2 to a porous-coated implant stimulated local bone ingrowth and gap healing. The enhancement of bone formation within the implant (bone ingrowth) was inversely related to dose.
authors.affiliation: Department of Anatomy and Cell Biology, Rush Medical College, 600 South Paulina Street, Suite 507, Chicago, IL 60612-3832, USA. rick_sumner@rush.edu
authors.forename: D R
authors.initials: DR
authors.lastname: Sumner
authors.forename: T M
authors.initials: TM
authors.lastname: Turner
authors.forename: R M
authors.initials: RM
authors.lastname: Urban
authors.forename: T
authors.initials: T
authors.lastname: Turek
authors.forename: H
authors.initials: H
authors.lastname: Seeherman
authors.forename: J M
authors.initials: JM
authors.lastname: Wozney
mesh_terms: D000818:Animals; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology*; D001861:Bone Regeneration / Q000187:drug effects*; D004285:Dogs; D017102:Fracture Healing / Q000187:drug effects*; D006811:Humerus / Q000187:drug effects / Q000502:physiology / Q000601:surgery; D023421:Models, Animal; D016348:Osseointegration / Q000187:drug effects; D019736:Prostheses and Implants; D011994:Recombinant Proteins / Q000494:pharmacology; D016212:Transforming Growth Factor beta
chemical_list: C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta