[Comparative study of vertebral body stress distribution following insertion of artificial lumbar intervertebral disc].
OBJECTIVE
To study vertebral body stress distribution of normal disc, post-Diskectomy and artificial disk respectively by 3-D finite element methods, and to explore artificial intervertebral disk insertion impact on stress distribution of vertebral body.


METHODS
Models of normal disk, post-Diskectomy, artificial disk and L(4 - 5) motion segment were established by using finite element software MSC. MARK, then vertebral body stress was analyzed through model of L(4 - 5) motion segment respectively.


RESULTS
The vertebral body's stress was the smallest after insertion of artificial intervertebral disk (AID), and its stress distributed equally. But the stress under post-discectomy was bigger than the normal disc's in all the motion state. On the other hand, the stress distribution state of the post-discectomy changed while the spine were in different motion state, during the spine flexion, the stress in the anterior of vertebral body was the biggest; While extension, in the posterior and in right flexion state, the biggest stress was in the right. While vertical compression and rotation, the stress distributed equally.


CONCLUSIONS
The results illustrate that the vertebral body's stress is the smallest after insertion of AID in 3 groups of all motion state, and its stress distributes equally. But the level of vertebral body stress increases after discectomy comparing with the normal group. In generally, it is much more reasonable that the disc is reconstructed with AID because of the biomechanical effect on vertebral body made by AID insertion.
Xu
Yi-chun
YC
Department of Orthopaedics, the Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510630, China.
Liu
Shang-li
SL
Zhang
Mei-chao
MC
Huang
Dong-sheng
DS
Wang
Qi-you
QY
D017586:Diskectomy; D020342:Finite Element Analysis; D006801:Humans; D007403:Intervertebral Disc / Q000502:physiology* / Q000601:surgery; D008159:Lumbar Vertebrae / Q000502:physiology* / Q000601:surgery; D008954:Models, Biological; D019736:Prostheses and Implants; D019919:Prosthesis Implantation; D013314:Stress, Mechanical