Hip Fractures: Acetabular

A less common hip fracture involves the acetabulum or socket of the hip joint. These fractures have become rarer (about 3 in every 100,000) since the advent of mandatory seatbelt use.³ Acetabular fractures occur when the femoral head impacts the articular surface of the acetabulum, usually from substantial impact and force, making them more common in younger people. Because the acetabulum encompasses a large bony area, the fracture can present in different locations (anterior (front) column, posterior (back) column, or wall) and orientations.

To understand hip fractures, we need to know the anatomy of the hip joint. The pelvic bone is connected to the head of the femur with a ball and socket joint. The surfaces of the ball and socket are covered in articular cartilage, which can be damaged during a traumatic fracture. In these cases, it is not uncommon for patients to develop post-traumatic arthritis in the future.

Causes

Acetabular hip fractures¹,³,⁴happen in young people and are usually caused by significant trauma such as a vehicular accident. Because of this, acetabular fractures are often one of many injuries following an incident and have considerable bleeding that requires emergent care. Elderly patients with osteopenia/osteoporosis can also experience acetabular fractures following a fall. Pathologic fractures occur in 5% of hip fractures due to disease.¹

Symptoms

If you are unable to put weight on your leg due to pain in your hip and you have experienced a traumatic injury (such as a fall), it is important to visit a qualified orthopedic specialist. A proper diagnosis can prevent further damage and allow for the best outcome. The most common symptoms of a hip fracture include:

Pain usually in the groin and upper thigh,
Inability to bear weight,
Inability to twist the upper leg in or out.

Diagnosing

Because of the force required to cause an acetabular fracture, most patients will have multiple injuries and end up in the emergency room via ambulance. The diagnostic process begins with a physical examination and medical history. X-rays are often the definitive diagnostic imaging test for an acetabular hip fracture. A CT scan may be ordered to provide a more detailed image of the fracture, allowing your orthopedic surgeon to plan your treatment better.

Treatments

Treatment of a hip fracture depends on the fracture location, whether the fracture is stable, and the patient’s ability to undergo surgery. Surgical repair of acetabular fractures is the most common form of treatment.

Conservative Treatment Options

Conservative treatment does not offer the best outcomes, so it is reserved for patients who are at high surgical risk and have stable, non-displaced fractures. Conservative treatment options include:

Bed rest for comfort and to avoid fracture displacement,
Crutches or a walker to offload weight,
Immobilization or range of motion (ROM) restrictions,
Anti-coagulants to reduce blood clot risk.

Surgical Treatment

Due to the severity of the trauma and internal injuries sustained, surgery is the most common treatment for acetabular fractures.

Total hip replacement
Open reduction and internal fixation (ORIF)
Percutaneous fixation (pinning of the bone in place through the skin) is an option for patients who may not tolerate a surgical procedure.

Complications

All surgical procedures come with risks: pain, bleeding, nerve damage, and wound problems. Your orthopedic surgeon will discuss risks and possible complications before surgery. Complications following arthroplasty include hip dislocation, hardware loosening, leg length discrepancy, and peri-prosthetic fractures (fractures above/below the hardware). Hip fractures also have a risk of medical complications, including delirium, pulmonary embolism (blood clot in the lung), deep venous thrombosis (blood clot in the leg), pneumonia, myocardial infarction (heart attack), heart failure, urinary infection, acute kidney injury, anemia, and skin pressure ulcers.

References:

Emmerson BR, Varacallo M, Inman D. Hip Fracture Overview. PubMed. Published 2020. https://www.ncbi.nlm.nih.gov/books/NBK557514/
Fischer S, Gray J. Hip Fractures – OrthoInfo – AAOS. Aaos.org. Published November 2020. https://orthoinfo.aaos.org/en/diseases–conditions/hip-fractures/
Hoge S, Chauvin BJ. Acetabular Fractures. PubMed. Published 2020. https://www.ncbi.nlm.nih.gov/books/NBK544315/
Smith, MD JM, Dunbar, MD RP, Lowe, MD JA, Provus, MD JD. Acetabular Fractures. Ortho Info. Published February 2016. https://orthoinfo.aaos.org/en/diseases–conditions/acetabular-fractures/