11. Lateral compression
11. 侧方挤压型
This is the most common type of pelvic fracture [22]. Lateral forces cause internal rotation of the hemipelvis. This results in coronal ramal fractures, contralateral SIJ disruption and central acetabular fractures. Unlike AP compression fractures, lateral compression injuries have a high association with sacral fractures, reported to be in the region of 88% [22].
这是骨盆骨折最常见的类型 [22]。侧方暴力引起半骨盆向内旋转。这导致冠状位上耻骨支骨折，对侧骶髂关节分离和髋臼中央骨折。与前后挤压骨折不同，侧方挤压损伤与骶骨骨折高度相关，报道称大约为88%[22]。
Pelvic volume tends to reduce in lateral compression fractures,with haemorrhage more likely to tamponade spontaneously.Young–Burgess classi?cation is as follows:
LC 1: Ipsilateral ‘buckle’ sacral and coronal pubic rami fractures;
LC 2: Type 1 + ipsilateral iliacwing fracture or posterior SIJ disruption;
LC 3: Type 2 + external rotation of the contralateral hemipelvis±contralateral saggital ramal fractures.
Type 1 fractures are stable, types 2 and 3 are rotationally unstable but vertically stable owing to the intact posterior sacroiliac ligaments (Fig. 5a and b).
由于出血能够自发填塞，侧方挤压型骨折骨盆容积倾向于减少。Young–Burgess分类如下：
LC 1型：同侧骶骨扭转，冠状位耻骨支骨折；
LC 2型：1型+同侧髂骨翼骨折或后部骶髂关节分离；
LC 3型：2型+对侧半骨盆外旋转±矢状位耻骨支骨折。
1型骨折稳定，2型和3型由于骶髂后韧带完整表现旋转不稳而垂直稳定(图5a- b)。
图5：(a 和 b) LC2型骨折。注意右侧耻骨支骨折和骶粗隆骨折。骶骨骨折在CT片上更容易辨认(b, 箭头所示)。
12. Vertical shear
12. 垂直剪切型
Vertical shear injuries are vertically and rotationally unstable owing to disruption of the posterior ligaments. Often the vertical force is the femur, which causes vertically orientated ramal fractures anteriorly and ligamentous injury posteriorly. The hemipelvis is shifted cranially. A subtle sign of instability is a fracture of the tip of the transverse process of L5, caused by avulsion of the iliolumbar ligament. There is a high rate of associated injuries to the torso and spine and a high rate of haemodynamic instability (Fig. 6).
垂直剪切型损伤由于后方韧带断裂而致垂直和旋转不稳。垂直力通常来自股骨，引起前方垂直方向的耻骨支骨折和后方韧带损伤。半骨盆向头侧移位。不稳定骨折的一项敏感指征是L5横突尖骨折，由髂腰韧带撕裂伤引起。此型骨折躯体和脊柱合并伤以及血流动力学不稳比率较高(图. 6)。
图6：垂直剪切型骨折。垂直方向耻骨支骨折，右半骨盆朝头侧移位。垂直和旋转不稳。
