title: Artificial disc and vertebra system: a novel motion preservation device for cervical spinal disease after vertebral corpectomy.
abstract: OBJECTIVE
  To determine the range of motion and stability of the human cadaveric cervical spine after the implantation of a novel artificial disc and vertebra system by comparing an intact group and a fusion group.
  
  
  METHODS
  Biomechanical tests were conducted on 18 human cadaveric cervical specimens. The range of motion and the stability index range of motion were measured to study the function and stability of the artificial disc and vertebra system of the intact group compared with the fusion group.
  
  
  RESULTS
  In all cases, the artificial disc and vertebra system maintained intervertebral motion and reestablished vertebral height at the operative level. After its implantation, there was no significant difference in the range of motion (ROM) of C(3-7) in all directions in the non-fusion group compared with the intact group (p>0.05), but significant differences were detected in flexion, extension and axial rotation compared with the fusion group (p<0.05). The ROM of adjacent segments (C(3-4), C(6-7)) of the non-fusion group decreased significantly in some directions compared with the fusion group (p<0.05). Significant differences in the C(4-6) ROM in some directions were detected between the non-fusion group and the intact group. In the fusion group, the C(4-6) ROM in all directions decreased significantly compared with the intact and non-fusion groups (p<0.01). The stability index ROM (SI-ROM) of some directions was negative in the non-fusion group, and a significant difference in SI-ROM was only found in the C(4-6) segment of the non-fusion group compared with the fusion group.
  
  
  CONCLUSIONS
  An artificial disc and vertebra system could restore vertebral height and preserve the dynamic function of the surgical area and could theoretically reduce the risk of adjacent segment degeneration compared with the anterior fusion procedure. However, our results should be considered with caution because of the low power of the study. The use of a larger sample should be considered in future studies.
authors.affiliation: Second Department of Orthopedics, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Dong
authors.affiliation: Second Department of Orthopedics, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Lu
authors.affiliation: Second Department of Orthopedics, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
authors.forename: Teng
authors.initials: T
authors.lastname: Lu
authors.affiliation: Department of Plastic Surgery, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
authors.forename: Baobao
authors.initials: B
authors.lastname: Liang
authors.affiliation: Department of Orthopedics, Xi'an Honghui Hospital of Xi'an Jiaotong University, Xi'an, China.
authors.forename: Junkui
authors.initials: J
authors.lastname: Xu
authors.affiliation: Second Department of Orthopedics, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Qin
authors.affiliation: Second Department of Orthopedics, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
authors.forename: Xuan
authors.initials: X
authors.lastname: Cai
authors.affiliation: Second Department of Orthopedics, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
authors.forename: Sihua
authors.initials: S
authors.lastname: Huang
authors.affiliation: Second Department of Orthopedics, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Wang
authors.affiliation: Second Department of Orthopedics, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
authors.forename: Haopeng
authors.initials: H
authors.lastname: Li
authors.affiliation: Second Department of Orthopedics, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
authors.forename: Xijing
authors.initials: X
authors.lastname: He
mesh_terms: D000328:Adult; D002102:Cadaver; D002574:Cervical Vertebrae / Q000601:surgery; D019299:Decompression, Surgical; D005260:Female; D006801:Humans; D008297:Male; D019736:Prostheses and Implants; D019919:Prosthesis Implantation; D013118:Spinal Cord Diseases / Q000601:surgery*; D013123:Spinal Fusion / Q000295:instrumentation* / Q000379:methods