Causes

How do fractures of the pelvis commonly happen?

The anatomy of the pelvis results in a wide variety of fracture patterns. Avulsion fractures of the iliac spines or the ischial tuberosity result from over-pull of the muscles. Impact from the side compresses the ring and may cause a fracture of the wing of the ilium or fractures through the pubic rami in front and the sacroiliac complex at the back. Impact from the front may cause fractures of the pubic rami on both sides. Impact driving the leg up into the pelvis may result in a shear fracture involving the front and back or may break the hip socket (acetabulum). A straddle injury in which the legs are forced too far apart may disrupt the pubic symphysis and the anterior sacroiliac ligament.