经口前路寰枢椎钢板内固定手术的应用解剖

Applied anatomy of transoral atlantoaxial internal fixation

目的:为经口前路进行寰枢椎钢板内固定手术提供解剖基础。方法:新鲜冰冻尸头标本6个,头颈部标本30个模拟经口入路手术过程,逐层解剖至上颈髓,观察并测量手术入路上的径向、轴向及水平方向的重要结构及解剖数据。寰枢椎干骨标本30个,对与内固定相关的骨性参数进行测量。结果:经口入路至颈髓的操作深度最大(103.8±6.2)mm,可显露范围长(52.1±3.5)mm,宽(39.4±2.2)mm,手术安全范围由双侧椎动脉构成,呈一不规则的倒置梯形,其边界在C2/3横突间距离中线仅(11.4±1.4)mm,故在此区域操作时应十分小心。寰椎理想进钉点距离中线(15.0±2.0)mm,理想钉道角度(12.5±2.5)°,理想钉道深度(20.8±1.5)mm。结论:经口前路钢板内固定手术是安全可行的,主要手术操作区域中双侧椎动脉内缘位于显露范围之外,钢板宽度应介于20～42 mm,寰椎螺钉长度不宜超过18 mm。

Objoetive： To provide anatomic profiles for the surgery of transoral atlantoaxial internal fixation. Mothods：Transoral approach was performed in 6 fresh and 30 cadaveric specimens, and then special anatomic data were measured at the coronal, axial and sagittal planes. Bone structures concerning with atlanatoaxial internal fixation were measured in 30 specimens of atlas and axis. Results： During the process, the maximal depth to cervical spine was （103.8±6.2） mm, the exposure zone （52.1±3.5）mm in the length and （39.4±2.2）mm in the width. The safe zone appeared as an inverted trapezia bordered by bilateral vertebral arteries. Distance between the edge of this zone to the midline at C2/3 level was just （11.4±1.4）mm, which implied that the operation in this region should be rather careful. The distance between the ideal screw inserting point on the atlas to the middle point of C1 was （15.0±2.0）mm, the ideal angle of screw （12.5°±2.5°）, and the ideal depth of screw （20.8±1.5）mm. Conelusions： Atlantoxial internal fixation is safe and feasible. The inner edge of vertebral artery is outside of exposure range, the width of the plate should be between 20-42 mm, and the length of screw on C1 should be less than 18mm.