Acetabular Fracture

An acetabular fracture is a break in the socket portion of the "ball-and-socket" hip joint. These hip socket fractures are not common — they occur much less frequently than fractures of the upper femur or femoral head (the "ball" portion of the joint).

The majority of acetabular fractures are caused by some type of high-energy event, such as a car collision. Many times patients will have additional injuries that require immediate treatment.

In a smaller number of cases, a low-energy incident, such as a fall from standing, may cause an acetabular fracture in an older person who has weaker bones.

Treatment for acetabular fractures often involves surgery to restore the normal anatomy of the hip and stabilize the hip joint.

Cause

  • An acetabular fracture results when a force drives the head of the femur against the acetabulum. This force can be transmitted from the knee (such as hitting the knee against the dashboard in a head-on car collision) or from the side (such as falling off a ladder directly onto the hip). Depending upon the direction of the force, the head of the femur is sometimes pushed out of the hip socket, an injury called hip dislocation.
  • When the fracture is caused by high-energy impact, patients often experience extensive bleeding and have other serious injuries that require urgent attention.
  • Acetabular fractures are sometimes caused by weak or insufficient bone. This is most common in older patients whose bones have become weakened by osteoporosis. Although these patients do not often have other injuries, they may have complicating medical problems, such as heart disease or diabetes.

Symptoms

  • A fractured acetabulum is almost always painful. The pain is worsened with movement.
  • If nerve damage has occurred with the injury, the patient may feel numbness, weakness, or a tingling sensation down the leg
Nonsurgical Treatment Surgical Treatment

Nonsurgical treatment may be recommended for stable fractures in which the bones are not displaced. It may also be recommended for patients who are at higher risk for surgical complications. For example, patients with severe osteoporosis, heart disease, or other medical concerns may not be able to tolerate surgery.

Nonsurgical treatment may include:

  • Walking aids. To avoid bearing weight on your leg, your doctor may recommend that you use crutches or a walker for up to 3 months—or until your bones are fully healed.
  • Positioning aids. If your doctor is concerned about joint instability—the ball of your hip sliding within or popping out of the socket— he or she may restrict the position of your hip, limiting how much you are allowed to bend it. A leg-positioning device, such as an abduction pillow or knee immobilizer, can help you maintain these restrictions.
  • Medications. Your doctor may prescribe medication to relieve pain, as well as an anti-coagulant (blood thinner) to reduce the risk of blood clots forming in the veins of your legs.
  • Most acetabular fractures are treated with surgery. Because acetabular fractures damage the cartilage surface of the bone, an important goal of surgery is to restore a smooth, gliding hip surface.
  • During the operation, your doctor will reconstruct the normal anatomy of the hip joint—aligning the bone fragments to restore the surface of the acetabulum, and fitting the femoral head into the hip socket.
  • Timing of surgery. Most acetabular fractures are not operated on right way. Your doctor may delay your surgery a few days to make sure your overall condition is stable and you are prepared for the procedure.
  • During this time, your doctor may place your leg in skeletal traction to immobilize the fracture and prevent additional injury or damage to the hip socket. In skeletal traction, a metal pin is implanted in the femur or tibia bone. Weights attached to the pin gently pull on the leg, keeping the broken bone fragments in as normal a position as possible. For many patients, skeletal traction also provides some pain relief.