三角定位法确定颈7椎弓根螺钉进钉点的解剖定位研究

Trian gle meth od used for localization of C7 pedicle screw entry point

目的：探讨第7颈椎椎弓根进钉点的解剖定位研究。方法：选取30具成人第7颈椎干燥标本进行解剖学观测。测量成人第7颈椎椎弓根的高度、宽度，以侧块上缘、外侧缘及侧块内上角与外下角连线围成的三角形中点作为进钉点，测量此进钉点植入椎弓骨螺钉所需角度。结果：第7颈椎椎弓根可容纳直径3．5mm，长度24mm椎弓根螺钉。侧块上缘、外侧缘及侧块内上角与外下角所构成三角形近似等边三角形，解剖学结构清晰，以此进钉点植入椎弓根螺钉所需外展角约35度。结论：以侧块上缘、外侧缘及侧块内上角与外下角连线围成的三角形中点作为进钉点，解剖学特征恒定，标志清晰，易于定位，可以此作为临床定位第7颈椎椎弓根螺钉进钉点解剖学依据。

Objective：To localize anatomic entry point for seventh cervical vertebrae.Methods： 30 bone specimens were used to measure the width and height of C7 pedicle.The triangle were formed with three body landmarks：surperior margin, lateral margin and di-agonal of lateral mass.The midpoint of this triangle were used for entry point of pedicle screw.The abduction angle and cephalad angle were also measured.Results：The C7pedicle screw were long and wide enough to accept 24＊3.5mm pedicle screw.The triangle formed by surperior margin, lateral margin and diagonal of lateral mass easy to identify.Abduction angle were 35 degree approximately.Conclu-sion：Anatomical symbol of the entry point using midpoint point formed by surperior margin, lateral margin and diagonal of lateral mass were easy to be exposed and identified in operation.Transpedicular screw could be precisely placed with limited exposure.