The hip joint is a ball and socket joint. The socket part is lined with smooth cartilage and is called the acetabulum, which is part of the pelvis. When the socket is fractured, it is called an acetabular fracture. Such fractures are far less common than fractures to the ball part of the joint.
Acetabular fractures usually produce hip pain, but may also cause diffuse pain in the groin and leg. Putting weight on the affected leg can be painful, but it still may be possible to put weight on it.
Causes and Risk Factors
Acetabular fractures are usually caused by either high-energy trauma, most commonly from an automobile accident, or from what is called an insufficiency fracture. An insufficiency fracture is most common in older patients and is caused by the bone being weakened by osteoporosis. Older women tend to experience this type of fracture more often than older men.
If the fracture occurred in tandem with other significant injuries, for example in a high-energy impact such as an auto accident, a thorough examination to evaluate the injuries is usually conducted.
For acetabular fractures, a physician will generally take a full medical history, perform a physical examination and order X-rays and/or a CT scan to determine the extent and pattern of the fracture.
Depending on the extent of damage to the cartilage in the joint and the degree of instability in the hip, surgery may be required. Surgery is used to remove bone debris from the joint, restore stability to the hip and align the surface of the cartilage so the ball is held tightly within the socket of the joint. Surgery is most often performed in younger patients. For older patients, even if the alignment of the joint is not perfect, fractures may be allowed to heal on their own, especially if the ball of the joint is still in the socket and relatively stable.
After injury or surgery, patients must not put weight on the affected leg for up to three months. If a patient walks on the affected leg too soon, it risks displacing the joint again. Rehabilitation is required after surgery or after nonsurgical treatment.
Since acetabular fractures are often caused by auto accidents, such fractures are usually accompanied by other injuries that can complicate treatment of the fracture.
In the longer term, patients who have fractured their acetabulum face an increased risk of arthritis in the joint.