经口咽前路寰枢椎复位钢板内固定的外科解剖学研究

Surgical anatomy of transoral atlantoaxial reduction plate internal fixation

目的为经口咽前路寰枢椎复位钢板内固定设计和应用提供解剖学依据。方法对10例新鲜的头颈部标本使用经口咽前入路进行逐层的显微外科解剖,观察咽后壁的层次、椎动脉的走行、寰枢椎的解剖毗邻关系和寰枢椎前路钢板内固定的相关解剖参数等。结果(1)咽后壁分两层和两个间隙粘膜层、椎前筋膜层,咽后间隙和椎前间隙;(2)经此入路可显露从枕骨大孔前缘至C3椎体的范围;(3)寰椎和枢椎椎动脉距中线的距离分别为寰椎(252±23)mm和枢椎(184±26)mm;(4)寰椎和枢椎可显露宽度分别为(394±22)mm和(390±21)mm,寰椎进钉点(侧块中点)间距(a)为(314±33)mm,寰椎进钉点连线与枢椎进钉点(枢椎前表面中部上关节面内缘连线与前唇下缘线之间的等距离线位于矢状中线两侧旁开3～4mm的位置)连线的垂直间距(b)为(187±27)mm,a/b比值为15～17。结论经口咽前入路行寰枢椎前路钢板内固定可行,钢板的设计应以上述测量数据为依据。

Objective To provide anatomical data for transoral atlantoaxial reduction plate internal fixation. Method Microsurgical dissecting was performed on 10 fresh craniocervical specimens layer by layer according to transoral approach. Stratification of posterior pharyngeal wall, courser of vertebral artery, adjacent relationships of atlas and axis and correlative anatomical parameters of internal fixation to atlantoaxial joint were observed. Result (1) Posterior pharyngeal wall consisted of 2 layers and 2 interspace: mucosa, anterior fascia of vertebrae, posterior interspace of pharynx and anterior interspace of vertebrae. (2) The range from anterior rim of foramen magnum to C 3 could be exposed by this approach. (3) The distance between the vertebral artery at atlas and midline was (25 2±2 3) mm and that between the vertebral artery at axis and midline was (18 4±2 6) mm. (4) The width of atlas and that of axis could be exposed respectively to (39 4±2 2) mm and (39 0±2 1) mm. The distance(a) between 2 atlas screw inserting points(center of anterior aspect of C 1 lateral mass) was (31 4±3 3) mm. The vertical distance(b) between the connecting line of 2 atlas screw inserting points and that of 2 axis screw inserting points(at the central part of the vertebrae which was 3 4 mm lateral to the midline of C 2 vertebrae) was (18 7±2 7) mm The odds of a/b was 1 5～1 7. Conclusions Anterior atlantoaxial plate internal fixation through transoral approach is suitable and feasible. The design of the plate should be based on the above data.