Acetabular Fracture (Hip Socket Fracture)

First aid for a suspected hip socket fracture

1. Call 911 or your local emergency number.
2. Keep the person still and lying down, unless they are in danger where they are. Do not try to straighten the leg or help them walk.
3. Support the leg in the position found with rolled blankets or pillows.
4. Keep them warm and watch breathing and alertness.
5. Do not give food or drink, because surgery may be needed.
6. If they become pale, cold, sweaty or confused, tell the dispatcher. These are signs of shock from internal bleeding.

Anatomy: what the acetabulum is

The acetabulum is formed where the three pelvic bones (ilium, ischium and pubis) meet. It is lined with smooth cartilage and holds the femoral head. Its structure is described as two "columns" of bone (anterior and posterior) and two "walls" that form the rim of the cup. Fractures are classified by which of these parts are broken, most often using the Letournel classification.

Causes and risk factors

• High-energy trauma: motor vehicle and motorcycle crashes, pedestrian injuries, falls from height. These patients often also have head, chest, abdominal and other fractures.
• Low-energy falls in older adults: a fall from standing onto the side of the hip with osteoporosis. This group is increasing as the population ages.
• Hip dislocation: posterior wall fractures often accompany hip dislocation.

Symptoms

• severe pain in the hip, groin or buttock
• inability to stand or walk, or pain with any leg movement
• bruising and swelling over the hip
• a shortened, internally rotated leg if the hip is dislocated
• numbness, tingling or weakness in the foot if the sciatic nerve is injured, often with difficulty lifting the foot
• signs of blood loss and shock with high-energy injuries

Diagnosis

At the hospital, trauma teams first assess airway, breathing and circulation, and look for other injuries, following trauma protocols.

• Pelvic X-ray is part of the initial trauma evaluation, with special angled views (Judet views) in some centers.
• CT scan with 3D reconstruction is essential to see the exact fracture pattern, fragments in the joint and the position of the femoral head, and to plan surgery.
• Nerve examination of the leg before any treatment, because the sciatic nerve is injured in a significant minority of posterior fractures.

Treatment

Emergency care

• Treat shock and bleeding. See hemorrhagic shock.
• Reduce (put back) a dislocated hip urgently, ideally within 6 hours, to lower the risk of bone death.
• Skeletal traction may be used to hold the leg until surgery.

Non-surgical treatment

Used for fractures that are not displaced, are stable, or do not involve the weight-bearing part of the socket, and for people too unwell for surgery. It involves pain relief, early mobilization with crutches or a walker, and limited ("touch" or "toe-touch") weight-bearing for 6 to 12 weeks, with repeat X-rays.

Surgery

• Open reduction and internal fixation (ORIF): the surgeon realigns the fragments and fixes them with plates and screws to restore a smooth joint surface. It is usually done within a few days, once the patient is stable.
• Acute total hip replacement, sometimes combined with fixation, in older adults with poor bone quality, damaged femoral heads or pre-existing arthritis.
• Percutaneous screw fixation for some less displaced fractures.

Recovery and rehabilitation

• Hospital stay: often 1 to 2 weeks, longer with multiple injuries.
• Weight-bearing: usually limited for 6 to 12 weeks, using crutches or a walker.
• Physical therapy: starts early to maintain hip motion and strength, then builds over months.
• Blood clot prevention: blood-thinning medicines and early movement, because the risk of deep vein thrombosis is high.
• Return to work and activities: desk work may resume after 2 to 3 months; heavy manual work and sports often take 6 to 12 months.

Complications

• Post-traumatic arthritis: the most common long-term problem, more likely when the joint surface is not perfectly restored. Some people need a hip replacement years later.
• Avascular necrosis of the femoral head, especially after dislocation.
• Sciatic nerve injury, which may recover partially over months.
• Heterotopic ossification: abnormal bone forming in the muscles around the hip after surgery, which can stiffen the joint.
• Blood clots, infection, and wound problems.

Outlook

Outcomes depend on the fracture type, how accurately the joint surface is restored, the patient's age and bone quality, and other injuries. Younger people with well-reduced fractures often regain good hip function, though some develop arthritis. Older adults have a higher risk of losing independence, and early mobilization is critical.

Frequently asked questions

What is an acetabular fracture?

It is a break in the acetabulum, the socket of the hip joint formed by the pelvis. It usually happens in high-energy accidents such as car crashes, or in older adults after a fall onto the side. It affects the joint surface, so it often needs surgery.

How long does it take to recover from an acetabular fracture?

The bone usually heals in 8 to 12 weeks, with limited weight-bearing during that time. Regaining strength and normal walking typically takes 4 to 6 months, and full recovery from severe injuries can take up to a year or more.

Is an acetabular fracture the same as a hip fracture?

No. A typical hip fracture breaks the top of the thigh bone (femoral neck or intertrochanteric area). An acetabular fracture breaks the socket in the pelvis. Both cause hip pain and difficulty walking, but treatment and complications differ.

Can an acetabular fracture heal without surgery?

Yes, if the fracture is not displaced or does not involve the main weight-bearing area of the socket. Treatment then involves pain relief, crutches and limited weight-bearing for several weeks, with regular X-rays to check alignment.

Will I need a hip replacement after an acetabular fracture?

Some people do. Older adults may have a hip replacement at the time of injury. Others develop post-traumatic arthritis over years and need a replacement later. Accurate surgical repair of the joint surface lowers this risk.