摘要
目的 评价侧位X线片在了解下颈椎经关节螺钉固定中不同长度螺钉钉尖安全位置的作用。方法 选用7具尸体颈椎标本，从C3、4～C5、6直视下依次置人经关节螺钉，分别置人螺钉钉尖仅为四层皮质固定（0mm）和超出皮质2、4、6mm各42枚，分别摄标本侧位X线片。根据X线片，将每个椎体分为前Ⅰ、Ⅰ、Ⅱ、Ⅲ和Ⅳ区。逐一记录螺钉钉尖在X线片上相应椎体各区的位置。结果 共有87枚螺钉位于前Ⅰ区，其中42枚是当螺钉钉尖为四层皮质固定时（100％）；37枚是当钉尖超出下位椎体上关节突侧前方皮质2mm时（88％）；8枚是当钉尖超出4mm时（19％）。共有71枚螺钉位于Ⅰ区，其中5枚是当钉尖超出2mm时（2％）；34枚是当钉尖超出4mm时（80％）；32枚是当钉尖超出6mm时（76％）。10枚位于Ⅱ区的螺钉均是当钉尖超出6mm时的投影。没有发现螺钉钉尖位于Ⅲ区和Ⅳ区。不同长度的经关节螺钉钉尖在侧位X线片上的投影位置在颈椎各节段间差异无统计学意义（P〉0．05）。结论 在评价下颈椎经关节螺钉固定中不同长度的螺钉钉尖安全位置方面，侧位X线片有一定意义。下颈椎经关节螺钉理想长度的钉尖位置应该位于前Ⅰ区。
Objective To assess the value of lateral radiographs in determining the safe or hazardous locations of the tips of screws used in transartieular screw fixation. Methods Seven cervical spines were removed from embalmed cadavers. Three screws were placed into the facet at C3.4 - C5.6 in each specimen in each side. Four screw placements under direct visualization, including placement of the screw tip staying the ventral cortex of the superior facet （0 mm） and 2, 4, 6 mm overpenetration of the ventral cortex, were performed. After each placement, a lateral radiograph was taken. Each vertebral body was divided obliquely into four zones with isometry, with zone I the most posterior and superior. Another zone, superior to the posterosuperior point of the vertebral body was defined as pre-zone Ⅰ The number of screw tips seen in each zone were quantified for each placement. Results A total of 168 screw placements were performed. There were 87 screw tips found in prezone Ⅰ , with 42 of 42 （100%） screw placements that did not penetrate the ventral cortex （0 mm placement）, 37 （88%） screw placements 2 mm overpenetratd, and 8 （19%） screw placements 4 mm overpenetratd. Thirty four of 42 （80%） screw placements 4 mm overpenetratd were found in zone I , and 5 of 42 （12%） screw placements that penetrated the ventral cortex with 2 mm, and 32 （76%） screw placements 6 mm overpenetratd. All 10 screws found in zone Ⅱ were the screws penetrated the ventral cortex with 6 mm. None of the screw placements reached zones Ⅲ and Ⅳ .There was no statistically significant difference in the different cervical vertebrae number （ P 〉 0.05）. Conclusion Lateral radiographs may be valuable in evaluating cervical transartieular screw placement in different lengths. Ideal screw tip positions on lateral radiograph for this transartieular screw technique may be in prezone Ⅰ.
出处
《中国骨与关节损伤杂志》
2008年第6期444-446,共3页
Chinese Journal of Bone and Joint Injury
基金
浙江省医药卫生科学研究基金资助项目(2007B201)
关键词
颈椎
内固定器
经关节螺钉
Cervical vertebrae
Internal fixators
Transartieular screws
