title: In vivo evaluation of a resorbable osteoinductive composite as a graft substitute for lumbar spinal fusion.
abstract: The purpose of this prospective animal study was to evaluate the efficacy of a resorbable coral particulate to serve as a carrier with several doses of a bovine-derived osteoinductive bone protein mixture. A previously validated rabbit model for posterolateral intertransverse process lumbar spinal fusion was used. Posterolateral intertransverse process arthrodeses were performed at L5-L6 in 64 adult New Zealand white rabbits. The bone graft substitute evaluated consisted of a Biocoral/collagen composite with one of four doses (0, 100, 300, or 1,000 micrograms) of a bovine-derived osteoinductive bone protein extract (BP). Fusions were assessed at 5 weeks by manual palpation, radiography, histology, and biomechanical testing. Use of the Biocoral/collagen carrier without BP resulted in no solid fusions. Biocoral/collagen with 100 micrograms BP resulted in solid fusions in 31% (4 of 13) of the rabbits. Biocoral with 300 micrograms or 1,000 micrograms BP resulted in solid spinal fusion in all rabbits (27 of 27). There were no neurologic complications related to the growth factor or carrier. Small subcutaneous collections of serous fluids were noted in 26% of the animals in the 1st postoperative week, but resolved without problems by the 5th week. Such seromas may limit the clinical utility of this growth factor-carrier combination. Biocoral/collagen combined with the appropriate dose of bovine-derived osteoinductive bone protein was efficacious as a bone graft substitute for achieving posterolateral lumbar spinal fusion in the rabbit model. A dose of 300 micrograms BP was determined as the threshold to reliability produce solid spinal fusions.
authors.affiliation: Emory Spine Center, Department of Orthopaedics, Emory University, School of Medicine, Atlanta, Georgia USA.
authors.forename: S D
authors.initials: SD
authors.lastname: Boden
authors.forename: J H
authors.initials: JH
authors.lastname: Schimandle
authors.forename: W C
authors.initials: WC
authors.lastname: Hutton
authors.forename: C J
authors.initials: CJ
authors.lastname: Damien
authors.forename: J J
authors.initials: JJ
authors.lastname: Benedict
authors.forename: C
authors.initials: C
authors.lastname: Baranowski
authors.forename: S
authors.initials: S
authors.lastname: Collier
mesh_terms: D000042:Absorption; D000818:Animals; D001672:Biocompatible Materials / Q000493:pharmacokinetics; D001696:Biomechanical Phenomena; D001857:Bone Matrix; D001842:Bone and Bones / Q000737:chemistry*; D002113:Calcification, Physiologic; D002417:Cattle; D003094:Collagen; D004337:Drug Carriers; D005069:Evaluation Studies as Topic; D005260:Female; D008161:Lumbosacral Region; D011183:Postoperative Complications / Q000401:mortality; D011446:Prospective Studies; D011817:Rabbits; D011859:Radiography; D013123:Spinal Fusion / Q000379:methods*; D013131:Spine / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D014020:Tissue Extracts / Q000008:administration & dosage* / Q000627:therapeutic use
chemical_list: D001672:Biocompatible Materials; D004337:Drug Carriers; D014020:Tissue Extracts; D003094:Collagen