Posterior Wall Acetabular Fracture (Broken Hip Socket)

Physical Therapy Videos - Hip and Pelvis

What Is It?

A hip socket fracture is when the socket part of your hip joint breaks. Your hip joint helps you move your leg when you walk. It is made of two bones and works like a ball and socket. The ball is at the top of your thigh bone and is called the femoral head. The socket is part of your pelvis and is called the acetabulum. Both the ball and socket have a smooth layer called cartilage between them, which helps them move easily. A posterior wall break is when the back (posterior) part of your hip socket breaks. This part is important because it helps keep the ball in the socket. If it breaks, the ball can move out of place.

X-ray of a pelvis. The acetabulum is highlighted with a red line; the femoral head with a blue line. The two together make a “ball-in-socket” joint. The hip joint on the opposite side is labeled without the outlines. — Figure 1. X-ray of a pelvis. The hip socket is highlighted with a red line; the femoral head is highlighted with a blue line. The two together make a “ball-in-socket” joint. The hip joint on the opposite side is labeled without the outlines.

Bone models showing how the femoral head (top of the thighbone) sits within the acetabulum (hip socket). — Figure 2: Bone models showing how the femoral head (top of the thigh bone) sits within the hip socket (acetabulum).

How It Happens

Anyone can break their hip socket. Younger people might break it in a big accident, like a car crash or a fall from high up. Older people can break it in a small accident, like tripping and falling down. A break of the back wall of the socket often happens in car crashes when your knee hits the dashboard. This pushes your thigh bone against the back part of your hip socket and breaks it.

X-ray showing a posterior wall fracture dislocation (red arrow). The other side shows what a normal hip looks like. — Figure 3: X-ray showing a posterior wall fracture with the ball-and-socket out of place or dislocated (red arrow). The other side shows what a normal hip looks like. The metal seen is from the zipper and clothing the patient was wearing.

X-ray of a small fracture of the posterior wall (red arrow). The femoral head is still located in the correct place. — Figure 4: X-ray of a small fracture of the posterior wall (red arrow). The ball-and-socket joint in this image is in place and is not dislocated.

First Steps

A broken hip socket hurts a lot and makes it hard to walk. If you have this injury, you should go to the emergency room. You might also have other injuries, so doctors will check your whole body. They will take X-rays and maybe a CT scan to see the broken bone better. If the ball is out of the socket, doctors might need to put it back in place. They will give you medicine to help with the pain and may use weights to take pressure off your hip.

Treatment

Most of the time, this injury needs surgery. But in some cases, doctors might not operate. The goal is to fix the broken bone so it heals correctly and keeps the ball in the socket. During surgery, you will be asleep, and doctors might use screws, plates, or even a hip replacement to fix your hip. Surgery can be long, and you might need a blood transfusion.

X-ray of a smaller posterior wall acetabular fracture treated with small plates, screws, and wires. — Figure 5: X-ray of a smaller posterior wall acetabular fracture fixed with small plates, screws, and pins.

X-ray of a posterior wall acetabular fracture treated with a larger plate and screws. — Figure 6: X-ray of a hip socket fracture (posterior wall) that was treated with a larger plate and screws.

X-ray of a complex acetabular fracture, including a break in the posterior wall and other portions of the acetabulum, that required multiple plates and screws. — Figure 7: X-ray of a complex hip socket fracture, including a break in the posterior wall and other portions of the hip socket that required multiple plates and screws.

X-ray of a patient treated with a hip replacement. — Figure 8: X-ray of a patient with a hip socket fracture treated with a hip replacement.

Recovery

After surgery, you will work with a therapist to get your strength back and learn to walk again. Your doctor will tell you how much weight you can put on your leg and how much you can move your hip. It's important to follow these instructions to heal well. You might need pain medicine and blood thinners to help prevent blood clots. You will also need to do exercises at home that you learn in therapy to help you recover faster.

Long Term

After surgery, you might need a walker, crutches, or a cane. Physical therapy can help you get back to walking by working on your strength, balance, and endurance. Complications can happen, like blood clots, infections, trouble walking, hip stiffness, and hip arthritis. Arthritis is common after a hip socket fracture of the posterior wall. Fixing the ball and socket usually helps, but it might not stop all arthritis from happening. This means your hip might hurt and be stiff for a long time. Sometimes, you might need a hip replacement. There can also be problems with a hip replacement, like the ball moving out of place or your legs being different lengths. If your bone doesn't heal right, you might need more treatment. Extra bone might grow around your hip and cause pain and stiffness. Treatment can help, but it might not work for everyone. If an infection happens you might need more surgery and medicine. Your treatment team wants the best outcome for you, so following their instructions can help prevent many problems and help you recover well.