寰枢椎腹侧手术相关解剖学研究

Applied anatomical study on ventral operation of atlano-axis area

目的:评价寰枢椎腹侧手术内固定物置入时的相对危险性,为相关器械的设计和改进提供解剖学参考。方法:对37对寰枢椎干骨标本20条线性参数和8个角度参数进行测量,观察寰枢椎腹侧的形态结构。结果:寰椎上下关节面的轴截面是前内至后外方向并逐渐外向扭转的倒工字型曲面,其下1/3分位线恰位于骨质中央,纵长为(18.66±1.92)m m。枢椎侧块外2/3因椎动脉压痕形成空洞,使枢椎上外侧关节面下方骨质由前内向后外逐渐变薄,最薄处仅(1.67±0.65)m m。结论:寰枢椎腹侧手术时,在寰椎上下关节轴截面下1/3分位线置钉和沿枢椎体前唇至齿突基底后缘连线置钉能够获得最大界面把持力,而且安全性最高;寰枢椎外侧关节间融合时枢椎上关节面摩除的骨质厚度不能超过1.5m m,否则有损伤椎动脉的危险。

Objective： To evaluate the relative risk during ventral operation of atlanto-axis area and provide anatomical references for internal fixation designing. Methods： 20 liner and 8 angular parameters were measured respectively on 37 pairs vertebrae of atlas and axis. Results： The axial section of upper and inferior lateral joints of atlas was a curve which turned around gradually from anteromedially to posterolaterally with the shape of a inversed ＂ 工 ＂. Its inferior 1/3 line run through the median part of articular facet curved superoinferiorly with the length of （ 18.67±1.93 ）mm. A cavity, caused by pressing of vertebral artery, formed at the external 2/3 parts of axoid lateral mass, which led to the bone under superolateral articular surface of dentate thinned gradually from anteromedially to posterolaterally with the thinnest part of only （1.67±0.66）mm. Conclusions： For safe ventral operation in atlanto-axis area, the most hold strength is obtained for inserting screws under the direction of inferior 1/3 line of the axial section of superior and inferior lateral joint facets of atlas or under the direction from the prolabium to the hinder margin of odontoid process＇foundament. During the process of fusing the lateral joint of atlas and axis, vertebral artery maybe injured if the removed part of the bones of upper articular facet of axis exceed 1.5mm thickness.