Acetabular Fractures - Causes, Symptoms, and Treatment

Introduction

The hip joint is one of the ball and socket joints. The ball in the joint is the head of the femur bone, and the acetabulum forms the socket. It is a C-shaped structure formed by the connection of three bones of the hip: the ilium bone, the pubis bone, and the ischium bone. The acetabulum is located inferiorly and lateral to the pelvis forming a cup-like structure that receives the head of the femur bone and together forms the hip joint. The acetabulum has the following components, the anterior column, posterior column, anterior wall, posterior wall, medial wall, and the acetabular roof. The articular cartilage is smooth and slippery in nature, cushioning and protecting the bones and facilitating their movement. The ligaments connect the bones, support them, and prevent them from falling out of the socket. Any break in the socket of the hip joint or the acetabulum is called an acetabular fracture.

What Are the Causes of Acetabular Fractures?

Acetabular fractures are caused by high-energy trauma such as road accidents, crush injuries, dashboard injuries, falls from a ladder from a great height, or may be related to sports. These fractures are common in older people due to osteoporosis or weakened bones, which are susceptible to fractures called low-energy trauma.

What Are the Types of Acetabular Fractures?

Acetabular fractures are rare compared to hip fractures and are classified based on the fracture's severity and pattern. Judet and Letournel's acetabular fracture classification is divided into five elementary and five associated fractures.

Elementary fractures involve the main components of the acetabulum, which include:

• Posterior Wall Fractures: These are common acetabular fractures, usually dashboard injuries, that occur as a result of sudden force on the flexed knee, which travels along the head of the femur bone and breaks the posterior wall of the acetabulum.

• Posterior Column Fractures: These begin at the apex of the sciatic notch and are similar to dashboard injury fractures.

• Anterior Wall Fractures: They are relatively uncommon and are mainly caused by a hit or a fall on the side.

• Anterior Column Fractures: These fractures are commonly seen in older patients due to a fall from standing.

• Transverse Fractures: They involve both the anterior and posterior columns of the acetabulum.

Associated fractures include:

• T-Shaped Fractures: They are complex fractures, as they are transverse fractures along with a vertical fracture line, and all three bones that are the ilium, ischium, and pubis, separate from each other. It usually occurs due to a hit or falls on the side.

• Posterior Wall and Posterior Column Fracture: Dislocation of the femoral head is seen, and the involvement of both the posterior wall and column makes it more complex in nature.

• Transverse and Posterior Wall Fracture: Complex fractures are associated with nerve injury.

• Anterior Column and Posterior Hemitransverse: Most commonly seen in elderly patients, in this type of fracture, a part of the weight-bearing dome is still attached to the iliac wing.

• Combined Column Fractures: These are the most complex fractures where the dome or the roof of the acetabulum is seen as a floating fragment.

What Are the Symptoms of Acetabular Fractures?

Symptoms include:

• Extensive bleeding in high-energy trauma cases is associated with severe pain and swelling in the hip joint, which worsens during movement.

• Inability to move the leg and unable to stand or walk.

• Numbness or tingling sensation in the legs.

How Is an Acetabular Fracture Diagnosed?

Acetabular fractures require immediate management especially in high-energy trauma cases, as it involves significant blood loss and can lead to shock. The doctor will perform a thorough examination along with the movement of the toes and ankle to check nerve involvement.

The doctor will advise an X-ray and a computerized tomography (CT Scan) to determine the detailed view of the fracture pattern and any associated fractures, which helps in pre-operative planning. In some cases, duplex doppler ultrasound is advised to rule out deep vein thrombosis.

How Are Acetabular Fractures Managed?

Treatment of acetabular fractures depends on the pattern of the fracture, displaced or nondisplaced criteria, and the patient's overall health.

• Non-surgical management is recommended for people with osteoporosis, heart disease, or other risks of complications. It includes medications to relieve pain like local anesthetics and analgesics, and anticoagulants are prescribed to prevent blood clots.

• Crutches or a walker are advised for around three to four months or till the bones are completely healed.

• An abduction pillow or a knee immobilizer is recommended to immobilize joints or restrict joint movement. In some cases, traction is advised for six to eight weeks.

• Surgical management is necessary for severe or complex fractures and is managed by open reduction with internal fixation (ORIF). The fragments of the bone which are displaced are repositioned or reduced and fixed with the help of metal plates and screws on the outer surface of the bone to hold it together until complete healing is achieved.

• In some cases, when the injury is so severe that repair and reconstruction are not possible, a total hip replacement surgery is performed, during which the damaged bone and the cartilage are removed and replaced by a prosthesis or artificial parts.

What Are the Complications of These Fractures?

• Infections can occur at the incision site, causing a delay in healing, and are treated by cleansing the wound with antibiotics for one to two weeks.

• Post-traumatic arthritis is a type of arthritis that develops following trauma to the joints due to the wear and tear of the articular cartilage.

• Restriction of movement causes a decrease in the blood flow which can lead to the formation of blood clots resulting in deep vein thrombosis, which, when untreated, can lead to pulmonary embolism.

• Injury to the Sciatic nerve can be caused during trauma or surgery, which leads to a condition called foot drop, in which the patient would not be able to lift the leg or ankle to walk.

• Heterotopic ossification is a rare complication in which the bone tissues grow in the muscles, ligaments, and tendons around the socket. It interferes with the flexibility and functioning of the joint and needs surgical removal.

• Disruption of blood flow during injury can lead to avascular necrosis in the femoral head resulting in increased pain and loss of function.

What Are the Post-operative Instructions to Be Followed in These Fractures?

• Medications are prescribed post-surgery, which need to be taken appropriately.

• Using walking aids like crutches or walkers till the prescribed duration to prevent further complications.

• Maintaining good hygiene to prevent infections.

• Following a healthy diet and lifestyle and physical exercises, and range of motion therapy after healing is achieved.

Conclusion

Acetabular fracture is a fracture of the hip socket usually seen in youth due to road accidents or in older people due to a fall. These fractures are diagnosed by X-ray and CT Scan, which requires immediate attention or can lead to severe complications. These fractures are treated by immobilization along with medications and, in some severe cases, by surgical management. The patient can recover in a few months with proper care, evaluation, and a healthy lifestyle.