title: In Vivo Study of Hydroxyapatite-coated Hat Type Cervical Intervertebral Fusion Cage Combined With IGF-I and TGF-β1 in the Goat Model.
abstract: An in vivo animal experimental study.
  
  
  
  To investigate the hydroxyapatite (HA) coating in a modified fusion cage in improving the results of cervical intervertebral fusion and the role of combination of IGF-I and TGF-β1 treatment in a goat cervical spine interbody fusion model.
  
  
  
  Thirty-two goats were divided into 4 groups (n=8 for each) and underwent C3-4 discectomy and intervertebral fusion by the following methods: group 1, autologous tricortical iliac crest bone graft; group 2, cage only; group 3, cage coated with HA; group 4, cage coated with HA+IGF-I and TGF-β1. Radiography was performed preoperatively, postoperatively, and after 1, 2, 4, 8, and 12 weeks. At the same time points, disk space height, intervertebral angle, and lordosis angle were measured. At 12 weeks postoperatively, the goats were killed and fused segments were harvested. Biomechanical study was performed in flexion, extension, axial rotation, and lateral bending with a nondestructive stiffness method to determine the range of motion and stiffness. All cervical fusion specimens underwent histomorphologic studies.
  
  
  
  All 3 cage-treated groups showed significantly higher values for disk space height, intervertebral angle, and lordosis angle compared with the autologous tricortical iliac group at 1, 2, 4, 8, and 12 weeks after surgery (P<0.05). The stiffness of hat-shaped cervical intervertebral fusion cage coated with HA+IGF-I and TGF-β1 in flexion, extension, and lateral bending was significantly greater than that of the other groups (P<0.05), and the stiffness of hat-shaped cervical intervertebral fusion cage coated with HA in extension, axial rotation, and lateral bending was significantly greater than that of fusion with the bone graft and cage-only groups (P<0.05). Histomorphologic evaluation showed better fusion in 3 cage groups than in the bone graft group. In group 4 of the cage coated with HA+IGF-I and TGF-β1, a slightly more advanced bone matrix formation was shown than in groups without coating.
  
  
  
  HA coating can improve the fusion effect of the cervical intervertebral cage, and IGF-I and TGF-β1 can enhance bone fusion.
authors.affiliation: *Department of Orthopaedics, Zhongshan Hospital, Fudan University, Shanghai, China†Division of Plastic Surgery, The University of Mississippi Medical Center, Jackson‡JMS Burn and Reconstructive Center, Crossgate River Oaks Hospital, Brandon, MS§Changzheng Orthopaedics Hospital, Shanghai Second Military Medical University∥Department of Orthopaedics, Ruijin Hospital, Jiaotong University¶Department of Radiology, Changhai Hospital, Shanghai Second Military Medical University#Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, China.
authors.forename: Yutong
authors.initials: Y
authors.lastname: Gu
authors.forename: Feng
authors.initials: F
authors.lastname: Zhang
authors.forename: William C
authors.initials: WC
authors.lastname: Lineaweaver
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.forename: Lianshun
authors.initials: L
authors.lastname: Jia
authors.forename: Jin
authors.initials: J
authors.lastname: Qi
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Xuebin
authors.initials: X
authors.lastname: Zhen
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000627:therapeutic use*; D001857:Bone Matrix / Q000601:surgery; D002574:Cervical Vertebrae / Q000601:surgery*; D004195:Disease Models, Animal; D017586:Diskectomy / Q000379:methods; D004359:Drug Therapy, Combination; D017886:Durapatite / Q000627:therapeutic use*; D006041:Goats; D007334:Insulin-Like Growth Factor I / Q000627:therapeutic use*; D013123:Spinal Fusion / Q000379:methods*; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016212:Transforming Growth Factor beta / Q000627:therapeutic use*
chemical_list: D001672:Biocompatible Materials; D016212:Transforming Growth Factor beta; D007334:Insulin-Like Growth Factor I; D017886:Durapatite