Zhang Lihai, Peng Ye, Du Chengfei, Tang Peifu
Injury. 2014 Dec;45(12):2055-9. doi: 10.1016/j.injury.2014.10.052.
To compare the biomechanical stability of four different kinds of percutaneous screw fixation in two types of unilateral sacroiliac joint dislocation.
Finite element models of unstable Tile type B and type C pelvic ring injuries were created in this study. Modelling was based on fixation with a single S1 screw (S1-1), single S2 screw (S2-1), two S1 screws (S1-2) and a combination of a single S1 and a single S2 screw (S1–S2). The biomechanical test of two types of pelvic instability (rotational or vertical) with four types of percutaneous fixation were compared. Displacement, flexion and lateral bend (in bilateral stance) were recorded and analyzed.
Maximal inferior translation (displacement) was found in the S2-1 group in type B and C dislocations which were 1.58 mm and 1.90 mm, respectively. Maximal flexion was found in the S2-1 group in type B and C dislocations which were 1.55° and 1.95°, respectively. The results show that the flexion from most significant angulation to least is S2-1, S1-1, S1-2, and S1–S2 in type B and C dislocations. All the fixations have minimal lateral bend.
Our findings suggest single screw S1 fixation should be adequate fixation for a type B dislocation. For type C dislocations, one might consider a two screw construct (S1–S2) to give added biomechanical stability if clinically indicated.
比较四种不同经皮螺钉固定方法在两种单侧骶髂关节脱位类型中的生物力学稳定性。
本研究建立了不稳定Tile B型和C型骨盆环损伤的有限元模型。建模基于使用单枚S1螺钉（S1-1）、单枚S2螺钉（S2-1）、两枚S1螺钉（S1-2）以及单枚S1螺钉与单枚S2螺钉组合（S1–S2）进行固定。比较了四种经皮固定方法对两种类型骨盆不稳定（旋转或垂直）的生物力学测试。记录并分析了位移、屈曲和侧方弯曲（双侧站立位）情况。
在B型和C型脱位中，S2-1组的最大向下移位（位移）分别为1.58 mm和1.90 mm。在B型和C型脱位中，S2-1组的最大屈曲分别为1.55°和1.95°。结果表明，在B型和C型脱位中，从最大角度到最小角度的屈曲情况依次为S2-1、S1-1、S1-2和S1–S2。所有固定方式的侧方弯曲均最小。
我们的研究结果表明，对于B型脱位，单枚S1螺钉固定应是足够的固定方式。对于C型脱位，如果临床有指征，可考虑采用双螺钉结构（S1–S2）以增加生物力学稳定性。
