Fracture of the Pelvis
The pelvis is a ring-like structure of bones at the lower end of the trunk. The two sides of the pelvis are actually three bones (ilium, ischium, and pubis) that grow together as people age. Strong connective tissues (ligaments) join the pelvis to the large triangular bone (sacrum) at the base of the spine. This creates a bowl-like cavity below the rib cage. On each side, there is a hollow cup (acetabulum) that serves as the socket for the hip joint.
Many digestive and reproductive organs are located within the pelvic ring. Large nerves and blood vessels to the legs pass through it. The pelvis serves as an attachment point for muscles that reach down into the legs and up into the trunk of the body. A pelvic fracture is often associated with substantial bleeding, sensory and motor dysfunction, and other injuries.
How it happens
Growing teens, especially those involved in sports, are one group of people at risk for a particular type of pelvic fracture. Many “pulled muscles” may actually be undetected avulsion fractures of the pelvis. These fractures usually occur with sudden muscle contractions. A small piece of bone from the top of the hipbone is torn away by the muscle. This is a very stable type of fracture. It does not involve the entire pelvic ring or injure internal organs.
Another group at risk for pelvic fractures is elderly people with osteoporosis. An individual may fracture the pelvis during a fall, such as when getting out of the bathtub or descending stairs. These injuries usually do not damage the structural integrity of the pelvic ring, but may fracture an individual bone.
However, most pelvic fractures involve high-energy forces, such as those generated in a motor vehicle accident, crush accident or fall. Depending on the direction and degree of the force, these injuries can be life-threatening.
A broken pelvis is painful, often swollen and bruised. The individual may try to keep the hip or knee bent in a specific position to avoid aggravating the pain. If the fracture is due to trauma, there may also be injuries to the head, chest or legs. There is usually considerable bleeding, which can lead to shock. Summon emergency assistance. The injuries must be stabilized and the individual taken to a trauma center for definitive care. All pelvic fractures require X-rays, usually from different angles, to show the degree of displacement to the bones. A computed tomography (CT) scan may be ordered to define the extent of other injuries. The physician will also examine the blood vessels and nerves to the legs to see if they have been injured.
Stable fractures such as the avulsion fracture experienced by an athlete will normally heal without surgery. The physician may prescribe a painkiller (analgesic). The patient will have to use crutches or a walker, and will have to avoid putting weight on the hip until the bones heal. Because mobility may be limited for several months, the physician may also prescribe a blood-thinner to reduce the risk of blood clots forming in the veins of the legs.
Pelvic fractures that result from high-energy trauma are often life-threatening injuries because of the extensive bleeding. In these cases, doctors may use an external fixator to stabilize the pelvic area. This device has long screws that are inserted into the bones on each side and connected to a frame outside the body. The external fixator allows surgeons to address the internal injuries to organs, blood vessels and nerves.
What happens next depends on the type of fracture and the patient’s condition. Each case must be assessed individually, particularly with unstable fractures. Some pelvic fractures may require traction; for others, the external fixator may be sufficient. Unstable fractures may require surgical insertion of plates or screws of a biocompatible metal.
Stable pelvic fractures heal well. Pelvic fractures sustained during a traumatic incident such as an automobile accident may have significant complications, including severe bleeding and infection. However, these are due more to the associated injuries than to the fracture. If these injuries are addressed, the fracture usually heals well. Subsequent problems such as pain, impaired mobility, and sexual dysfunction are usually the result of damage to nerves and organs that is associated with the pelvic fracture.