[Biomechanical study on transarticular screw and plate fixation syetem in the lower cervical spine].
OBJECTIVE
To compare the cervical stabilities of transarticular screw fixation alone, and transarticular screw and plate fixation system.


METHODS
Twelve specimens of cervical vertebra containing C2-T1 were obtained from human cadaver. The three-column instability model was made at C4.5 and C5.6 levels. The specimens were stabilized with transarticular screw fixation alone, and transarticular screw and plate fixation system respectively. The ranges of motion of segments including intact group, transarticular screw fixation alone group and transarticular screw and plate fixation system group were measured under the torque of 2.0 N x m in flexion, extension, lateral bending, and torsion respectively under nonrestrictive and nondestructive condition.


RESULTS
The rang of motion (ROM) and neutral zone (NZ) of both transarticular screw fixation alone and transarticular screw and plate fixation system group were significantly smaller than those of intact group in all directions (P < 0.05). The transarticular screw and plate fixation system group allowed a very smaller ROM and NZ than transarticular screw fixation alone during extension, lateral bending and axial rotation except flexion (P < 0.05).


CONCLUSIONS
Cervical transarticular screw and plate fixation system provides better stability than transarticular screw fixation alone. If the transarticular fixation technique is preferred, transarticular screw and plate fixation system will be beneficial.
Liu
Guan-Yi
GY
Department of Orthopaedics, Sixth Hospital of Ningbo, Ningbo 315040, Zhejiang, China. lgysimon@yahoo.com.cn
Xu
Rong-Ming
RM
Ma
Wei-Hu
WH
Sun
Shao-Hua
SH
Feng
Jian-Xiang
JX
Wang
Yi-Jin
YJ
D001696:Biomechanical Phenomena; D001860:Bone Plates; D001863:Bone Screws; D002574:Cervical Vertebrae / Q000293:injuries / Q000601:surgery*; D005593:Fracture Fixation, Internal / Q000379:methods*; D006801:Humans; D016059:Range of Motion, Articular