[Comparison of statics characteristics between anterior transpedicular screws system and vertebral body screws system in lower cervical spine].

ABSTRACT

OBJECTIVE: To compare statics characteristics between anterior transpedicular screws (ATPS) system and vertebral body screws (VBS) system in lower cervical spine. METHODS: Sixteen fresh cervical specimens were collected and dissected into 32 different units (functional spinal unit, FSU), 8 units in C3,4, C4,5, C5,6 and C6,7 each. The subjects were randomly divided into group A and B. The anterior transpedicular screw-plate system and anterior vertebral body screw-plate system were implanted separately in group A and B. Then, the maximum axial pull out strength was tested and compared between two fixation system. RESULTS: Maximum pull out strength was (604.68 +/- 48.76) N in group A and (488.24 +/- 32.42) N in group B, and there was significant difference between two groups (t = 2.147, P < 0.05). There was no statistically significant difference in all FSU between anterior transpedicular screws system and vertebral body screws system (F(A) = 2.27, F(B) = 2.05, P > 0.05). CONCLUSION: The pull out strength of anterior transpedicular screws system is better than vertebral body screws system, and the anterior transpedicular screws has the biomechanical feasibility in clinic.