What is a pelvis fracture?
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. The pelvis holds many internal organs, so that in more severe cases, these injuries can cause a great deal of internal bleeding.
People of all ages may suffer from serious pelvic injuries after accidents involving falls from elevated heights, bikes, cars and motorcycles. Elderly people can fracture the pelvic bone with just a mild fall. Pelvis fractures are now happening most frequently among 15- to 28-year-old males, although pelvis fractures among women happen most frequently over the age of 35.
Anatomy of the pelvis
The pelvic bone sits between the lower limbs and abdomen in humans, where it connects the spinal lumbar region to the femurs. The pelvis can be divided into the following parts:
- Pelvic girdle (hip bones)
- Pelvic spinal region (coccyx and sacrum)
- Pelvic cavity, which is subdivided into the following parts:
- Greater pelvis (above rim of pelvis)
- True pelvis (below rim of pelvis)
- Pelvis floor/diaphragm (below pelvic cavity)
- Perineum (below floor/diaphragm)
The pelvis is made up of three large bones, in addition to three to five smaller bones in the coccyx. The sacrum and coccyx form the pelvis in the posterior dorsal, and the two hipbones form the lateral and anterior portion of the pelvis. The ilium, ischium and pubis remain separate from one another before a human hits puberty, and begin to fuse as one matures into adulthood.
Types of pelvis fractures
Whether pelvic fractures are mild or severe, they can generally be grouped into one of the two following categories:
- Stable fractures—When an individual suffers a mild pelvic injury with only one breaking point along the pelvic ring, limited or no disruption to the pelvic bone and limited internal or external bleeding, the fracture is considered “stable.” This denotes that the pelvis is still secure despite the injury, and that there is a good chance of a quick, successful and complete recovery.
- Unstable fractures—In more severe pelvis fractures in which two or more breaks along the pelvic ring have occurred, the injury is considered “unstable.” There may also be moderate to severe bleeding with this type of injury, and internal organs may be threatened.
Pelvis fracture symptoms will vary depending on whether the injury is mild or severe. All injuries to this region will cause severe pelvic pain and more serious cases may also have consequences such as internal bleeding. If you have suffered an injury to your pelvic region and you are suffering from some or all of the following symptoms, you may have fractured your pelvis:
- Abdominal bruising
- Back pain
- Coccyx pain
- Heightened pain and difficulty while walking
- Hip pain
- Intense pelvic pain
- Leg pain
- Pelvic bruising
- Pelvic swelling
More intense pelvis fractures may also cause the following symptoms:
- Bloody urine
- Left, lower and/or right abdominal pain
- Numb legs
- Weak legs
The following are the most common pelvis fracture causes:
- Intense impact—When individuals survive major traumas, such as car and motorcycle accidents or falls from great heights, they can seriously fracture the pelvis, regardless of age.
- Sports injuries—This is one of the less common pelvis fracture causes, but it can be very serious and painful. Football, soccer and rugby players are the most likely to fracture the pelvis during falls ending in unnatural positions. There are also rare cases of pelvis fracture resulting from training injuries.
- Moderate falls—Elderly people and those suffering from osteoporosis and other bone-weakening diseases may fracture the pelvis after only a moderate fall, because their bone structure is so fragile. Elderly people are also more likely to fall because of poor balance, compromised vision and medication side effects, so this population is especially susceptible to fractures. Some people with extremely weakened bones may even fracture their pelvises spontaneously without falling.
How is it diagnosed?
Since pelvis fracture symptoms vary, X-rays are usually used to pinpoint the nature of the injury. The X-ray images will show the physician what the bones and internal organs look like from several different angles. A computed tomography (CT) scan also may be necessary to better understand the extent of the injuries.
The physician also may perform various examinations to test for damage to the nerves and blood vessels in the legs. An injury to the pelvic bone itself does not typically cause serious damage and may even be able to heal without intervention, but if the internal organs are affected, it can become life threatening and may require surgery.