Pelvic fractures

Fractures of the pelvis are mostly a result of motor vehicle accidents (high-energy trauma) in young adults, and therefore often co-exists with other injuries or fractures. It may also occur in elderly due to falls from standing height (low-energy trauma).

Low-energy fractures (elderly) are usually isolated and do not damage the integrity of the pelvic ring. High-energy fractures (young) usually damage the integrity of the pelvic ring, has more than one fracture, and has associated visceral and neurovascular injuries.

These fractures are uncommon, with an incidence of 3 – 4 / 100 000 per year. Males are more often affected. The mortality is quite high in open pelvic fractures and is significant in closed fractures as well due to the possibility of injury of major vessels. Haemorrhage is the leading cause of death due to the proximity of major vessels to the pelvic ring. There is a high prevalence of poor functional outcome and chronic pain. CT is often necessary. They’re classified according to the Tile classification according to the stability of the posterior column. Tile A fractures are treated conservatively while B and C (unstable) are treated surgically.

Clinical features

Symptoms include pelvic pain, especially with movement or weightbearing and reduced range of motion of the hip joint. Pelvis instability can be detected on physical examination. There may be associated haematomas and injuries of nearby organs, like urethra, bladder, etc.

Diagnosis and evaluation

X-ray may give the diagnosis, but a CT is often used to provide detailed imaging and exclude associated injuries. Ultrasound and angiography may also be used to diagnose associated injuries.

When a pelvic fracture is discovered, other related injuries should be sought, including other fractures of the pelvis or acetabulum, and dislocation of the hip.

Classification

Pelvic fractures are classified according to the Tile classification (or the more modern Young and Burgess classification). The Tile classification considers the location of the fracture and the remaining stability of the pelvic ring. Each type is divided into three subtypes.

Tile type	Description	Detailed description
Type A	Stable fracture	Integrity of posterior arch of pelvis and pelvic diaphragm intact Physiological loading doesn’t cause dislocation
Type B	Partially unstable fracture	The posterior arch of the pelvis is partially injured Instability is visible “only” in the horizontal view
Type C	Unstable fracture	The posterior arch of the pelvis is completely injured Instability in all directions Pelvic diaphragm totally ruptures

Type B1 is the “open book fracture”, where the ligaments of the pubic symphysis are disrupted but the posterior arch is intact, causing the pelvis to open like an open book. Large vessels (internal iliac artery and vein) pass near to these ligaments, and so massive haemorrhage can occur.

Treatment

Patients may require initial resuscitation and stabilisation due to blood loss or visceral injuries. Temporary measures may be used to stop blood loss, like sandbags, straps, bean bags, military antishock trousers, external fixators, or pelvic clamps.

Once stabilised, definitive treatment should be sought. Stable (type A) fractures may be treated conservatively with bed rest and physical therapy. Type B and C fractures should be treated surgically, with ORIF or closed reduction and percutaneous fixation. Disruption of the symphysis requires fixation with a plate.

Acetabular fractures

Fractures of the acetabulum are, like pelvic fractures, a result of high energy motor vehicle accidents in young or low energy falls in elderly. Fractures to joint surfaces predispose to later osteoarthritis, so proper treatment is important.

Associated ipsilateral neurovascular injury, especially of the sciatic nerve, is not uncommon and must be kept in mind. Stable fractures may be treated conservatively, while unstable fractures are treated with internal fixation or hip replacement.

Classification

Acetabular fractures may be classified according to the Judet and Letournel system or the AO/ASIF classification. Judet and Letournel classifies them according to the oblique pelvic view on x-ray. AO/ASIF classifies them according to severity and complexity.

Clinical features

Neurovascular injury in the ipsilateral extremity, especially of the sciatic nerve, may be present in up to 40% of cases, and so proper physical examination is important. Injury to the femoral artery can compromise distal blood supply as well.

Diagnosis and evaluation

Initial evaluation is usually with x-ray, but proper evaluation requires CT to look for associated injuries.

Treatment

The goal of treatment is to restore the stability of the hip joint and the congruency of the joint surfaces, to prevent later complications. Choice of treatment depends on the fracture type, stability, patient’s general condition, and age.

Stable fractures are generally treated conservatively (protected weight bearing, crutches, walker). Unstable or incongruent fractures are treated surgically with ORIF. In elderly, total hip replacement may be performed. If there is neurovascular injury, surgical treatment should be urgent.

Traumatic hip dislocation

Traumatic dislocation of the hip refers to dislocation of the femoral head from the acetabular socket. It is rare and usually associated with other injuries, like acetabular fracture or hip fracture. It mostly occurs due to high energy trauma in young. 90% of traumatic hip dislocations are posterior. The leg is shortened and internally rotated. Treatment involves closed or open reduction.

It may lead to osteonecrosis of the femoral head, osteoarthritis, and sciatic nerve injury.

Classification

Hip dislocations are classified according to their direction, posterior or anterior.

Posterior hip dislocation accounts for 90% of cases and occurs due to axial load on the femur with the hip in a flexed and adducted position. This is the usual position when sitting in a car, in which case the force from the dashboard pushes on the femur, therefore called a “dashboard injury”.

Anterior hip dislocations are rare. They occur when the hip is in an abducted and externally rotated position, which is rare in vehicles.

Clinical features

In both types there is hip pain, which usually radiates to the knee. In posterior dislocation the leg is shortened and internally rotated. In anterior dislocation the leg is lengthened and externally rotated.

Diagnosis and evaluation

Initial evaluation is usually with x-ray, but proper evaluation requires CT to look for associated injuries.

Treatment

Treatment is closed reduction if the injury is < 6 hours old. Closed reduction should always be followed up by CT. Surgery is indicated if closed reduction is unsuccessful, the joint is unstable, or if there are fragments in the joint.