title: [Biomechanical evaluation of immediate stability of biodegradable multi-amino acid copolymer/tri-calcium phosphate composite interbody Cages in a goat cervical spine model].
abstract: A new kind of Interbody Cage made of multi-amino acid copolymer/tri-calcium phosphate (MAACP/TCP) composite was designed, and the purpose of this study was to evaluate immediate stability of MAACP/TCP Cage in a goat cervical spine model (C3-4). After the motion segment C3-4 was tested intact, 27 goat cervical spines were divided into three groups randomly. There were four groups group A. MAACP/TCP Cage group (n = 9), group B2 titanium Cage group (n = 9), group C2 autologous tricortical iliac crest bone group (n = 9) and group D: intact group (n = 27). Different Cage groups were implanted after complete discectomy (C3-4) was performed. Then they were tested in flexion, extension, axial rotation, and lateral bending with a nondestructive stiffness method. The range of motion (ROM) and relative stiffness were calculated and compared between groups. In comparison to the intact motion segment, MAACP/TCP Cage showed a significantly (P < 0.05) lower ROM and a significantly (P < 0.05) higher relative stiffness in flexion and lateral bending. In comparison to the tricortical iliac crest bone graft, MAACP/TCP Cage showed a significantly (P < 0.05) lower ROM and a significantly (P < 0.05) higher relative stiffness in extension, flexion and lateral bending. There was no significant (P > 0.05) difference in the ROM and relative stiffness between MAACP/TCP Cage and titanium Cage in extension, flexion and lateral bending. In comparison to titanium Cage, MAACP/TCP Cage showed a significantly (P < 0.05) higher ROM and a significantly (P < 0.05) lower relative stiffness in rotation.
  
  
  CONCLUSIONS
  MAACP/TCP Cage can provide enough immediate stability for cervical interbody fusion in a goat cervical spine model.
authors.affiliation: Department of Orthopedics, West China Hospital, Sichuan University, Chengdu 610041, China.
authors.forename: Chunguang
authors.initials: C
authors.lastname: Zhou
authors.forename: Yueming
authors.initials: Y
authors.lastname: Song
authors.forename: Chongqi
authors.initials: C
authors.lastname: Tu
authors.forename: Hong
authors.initials: H
authors.lastname: Duan
authors.forename: Fuxing
authors.initials: F
authors.lastname: Pei
authors.forename: Yonggang
authors.initials: Y
authors.lastname: Yan
authors.forename: Hong
authors.initials: H
authors.lastname: Li
mesh_terms: D020341:Absorbable Implants; D000596:Amino Acids / Q000737:chemistry*; D000818:Animals; D001696:Biomechanical Phenomena; D002130:Calcium Phosphates / Q000737:chemistry*; D002574:Cervical Vertebrae / Q000601:surgery*; D005069:Evaluation Studies as Topic; D005260:Female; D006041:Goats; D020007:Implants, Experimental; D011108:Polymers / Q000737:chemistry*; D013123:Spinal Fusion / Q000295:instrumentation
chemical_list: D000596:Amino Acids; D002130:Calcium Phosphates; D011108:Polymers; C020243:calcium phosphate