Anterior thoracic spinal fusion in dogs by injection of recombinant human bone morphogenetic protein-2 and a synthetic polymer.
The purpose of this study was to achieve spinal fusion in the absence of bone graft material using a new, injectable, and semi-liquid synthetic polymer (polylactic acid polyethylene glycol [PLA-PEG] block copolymer) containing recombinant human bone morphogenetic protein-2 (rhBMP-2). Twenty-seven skeletally mature beagles underwent anterior thoracic spinal fusion at T9-T10. Group I (n = 9) was injected with 1 mL of PLA-PEG block copolymer carrier alone into space under the vertebral pleura and the anterior longitudinal ligament. Group II (n = 9) was injected with 1 mL of PLA-PEG carrier containing 500 microgram of rhBMP-2. Group III (n = 9) was injected with 1 mL of PLA-PEG carrier containing 1000 microgram of rhBMP-2. In the Group I animals, no evidence of new bone formation was noted at the implanted sites both radiographically and histologically. In contrast, all of the nine animals in Group III showed new bone formation in 12 weeks, and four of the nine animals in Group II showed bony mass at the injected sites. However, vertebral bony fusion was incomplete despite the significant amount of new bone formation in both groups that showed new bone formation. In addition to resulting in improvements in the surgical procedure, injection of rhBMP-2 and a synthetic polymer is useful for bone formation for spinal fusion.
Takahashi
Jun
J
Department of Orthopaedic Surgery, Shinshu University, School of Medicine, Nagano, Japan. jtaka@hsp.md.shinshu-u.ac.jp
Saito
Naoto
N
Ebara
Sohei
S
Kinoshita
Tetsuya
T
Itoh
Hidehiro
H
Okada
Takao
T
Nozaki
Kazutoshi
K
Takaoka
Kunio
K
D000818:Animals; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology / Q000627:therapeutic use*; D004285:Dogs; D006801:Humans; D007773:Lactates / Q000494:pharmacology / Q000627:therapeutic use*; D010012:Osteogenesis / Q000187:drug effects; D011092:Polyethylene Glycols / Q000494:pharmacology / Q000627:therapeutic use*; D011859:Radiography; D011994:Recombinant Proteins / Q000494:pharmacology / Q000627:therapeutic use*; D013123:Spinal Fusion / Q000295:instrumentation / Q000379:methods*; D013904:Thoracic Vertebrae / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000187:drug effects / Q000601:surgery*; D016212:Transforming Growth Factor beta
C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D007773:Lactates; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C088513:poly(lactic acid-ethylene glycol); C499469:recombinant human bone morphogenetic protein-2; D011092:Polyethylene Glycols