Pelvis fractures occur when the pelvic bone structure, which includes the coccyx, hipbone and sacrum, is disrupted. The pelvic bone forms a ring around the sacrum, a large bone shaped like a triangle that joins the upper pelvic cavity, rear pelvic cavity and base of the spine right between the hipbones. The ilium (the largest and uppermost pelvic bone), ischium (rear and lower hip bone) and pubis (anterior and ventral of the pelvis) make up this vital and complex bone structure. Injuries to the pelvic region that disrupt these three components occur when a powerful force has been applied to the body, which may also affect the local organs. There are many precious internal organs held within the pelvis, so these injuries can cause a great deal of internal bleeding in more severe cases.