Transarticular screws versus Magerl lateral mass screws:an anatomic comparison of their possible effects on injury to spinal nerve roots / 中华创伤骨科杂志

ABSTRACT

Objective To compare anatomically the potential incidences of injury to the nerve roots of ventral and dorsal rami caused by the transarticular screws and Magerl lateral mass screws in the fixation of subaxial cervical spine.Methods Fixations with the transarticular screws and Magerl lateral mass screws were performed in this study.For each kind of fixation,20 screws were inserted from C3 to C7 in two specimens.A 20-ram long screw was used to over-penetrate the ventral cortex.The anterolateral aspect of the cervical spine was carefully dissected to allow ob- servation of the screw-ramus relationship.Results The overall percentage of nerve violation was significantly lower in the transarticular screw fixation(45%)than in the Magerl lateral mass screw fixation(90%).The difference was sta- tistically significant between the two fixation methods(P＜0.05).The greatest percentages of nerve violation caused by the transarticular screws and lateral mass screws were found at the dorsal ramus,25% and 45%,respectively. Conclusion The potential risk of nerve root violation caused by the transarticular screw technique is lower than that by the Magerl lateral mass screw technique in the lower cervical spine.