Fractures of the acetabulum are challenging orthopedic injuries to repair, at times leaving multiple small fragments of fractured bone and cartilage. Compounded by the location in a region challenging in which to work and fraught with risk, these “puzzle pieces” must be brought back together to restore hip function and mobility.
The acetabulum, commonly thought of as the socket of the ball-and-socket hip joint, may break in one of 10 different pattern.
Relative to hip fracture, acetabular fracture is uncommon. These fractures occur in two distinct patient populations:
- In younger patients, high-energy injuries cause the break, such as motor vehicle or bike accidents, or falls from significant height.
- In older patients with osteoporosis, low-energy injuries such as falls from standing height prompt the fracture.
Patients’ pain levels vary widely and are related to the injury pattern and mechanism of injury.
Risks with acetabular fracture
This fracture puts patients at considerable risk of developing post-traumatic arthritis, which may result in the need for hip replacement. Post-traumatic arthritis occurs due to damage to the articular surface of either the acetabulum or femoral head. Another potential complication with acetabular fracture is avascular necrosis, in which the blood supply to the femoral head is sufficiently damaged or stretched from dislocation that the bone subsequently dies and collapses, resulting in hip pain.
Acetabular fractures are commonly associated with multiple other injuries, such as to the abdomen, chest or head. With isolated acetabular fracture, the risk of shock is low, but concomitant injuries must be identified and treated appropriately.
Surgical treatment of acetabular fracture is complex and can result in complications and poor outcomes. While the infection risk is similar to that of other hip procedures, body mass index (BMI) is a predictor of infection and complications of operative treatment.
When patients with suspected acetabular fracture arrive at any hospital, the first order of business is to determine if the hip is reduced or dislocated. If dislocated, providers should perform urgent closed reduction prior to any transfers, as this procedure is crucial to preventing future complications.
If the hip is unable to be reduced or appears widely displaced, consult with a higher level trauma center for transfer.
Physical exams for patients who have potentially suffered this injury are minimal, usually differentiating between acetabular or hip fracture.
“There’s not much of a physical exam — you can check the ability for the ankle or toes to dorsiflex; and check the sciatic nerve, particularly the peroneal branch; and check sensation in the superficial peroneal and deep peroneal nerve distributions,” says Dr. Sems, indicating nerve status should be documented. “But there is not much that’s going to be able to distinguish this from a hip fracture.”