Pediatric Periacetabular Osteotomy (PAO)

The Children’s Health℠ Andrews Institute for Orthopaedics & Sports Medicine specializes in surgical orthopedic reconstruction and nonoperative treatments.

Our team works together to find your best options for quicker recovery, decreased pain and improved movement. Treatment plans are tailored to the specific needs of young children, teenagers and young adults with hip dysplasia, including the operative and nonoperative care.

What is Pediatric Periacetabular Osteotomy (PAO)?

Periacetabular osteotomy (PAO) is a surgery to correct hip dysplasia. Hip dysplasia can occur during development in the womb when the ball of the hip joint moves out of place, or if the thighbone slips out of place after birth or during childhood development due to abnormally shallow hip sockets. With hip dysplasia, the hip socket doesn’t completely cover the ball portion of the upper thighbone, which can cause instability (problems with balancing and walking), limping and pain.

During the surgery, the hip socket is cut loose from the pelvis and repositioned to cover more of the femoral head (highest part of the thighbone) to increase the stability of the hip joint. If you have hip dysplasia on both hips, the surgeries will be performed separately and four to six months apart.

What are the benefits of Pediatric Periacetabular Osteotomy (PAO)?

PAO has several advantages compared to other treatment options. The surgery realigns the socket to improve movement, decreases pain and helps stop joint damage that can lead to arthritis.

Periacetabular Osteotomy compared to Total Hip Replacement (THR).

For some hip orthopedic conditions, surgeons perform a total hip replacement (THR) surgery that replaces natural bone in the hip with an implant. For young children, teenagers and young adults with hip dysplasia, PAO surgery is a better option for improved long-term outcomes with fewer side effects. THR implants aren’t as stable as a normal hip joint and can lead to dislocations, resulting in movement restrictions after surgery and for the rest of your life. PAO surgery doesn’t have these restrictions, which means more activities with fewer dislocation concerns.

Artificial implants can wear out over time and you may need additional surgeries later in your life to replace the joint. PAO surgery typically resolves the problem with one procedure. Maintaining the natural bone in a PAO surgery will also preserve sensations of the hip joint compared to decreased feelings with an implant. Your surgeon will be able to determine which option is best based on your condition, age and overall health.

What are the risks of Pediatric Periacetabular Osteotomy (PAO)?

PAO is quite safe, but like any other surgery, there can be risks or complications. If the femoral head is severely out of alignment, or if it isn’t properly rounded, your surgeon may need to re-form it with a procedure called an intertrochanteric osteotomy.

Other possible risks include deep vein thrombosis or DVT (blood clots), improperly healed bones, nerve damage, pulmonary embolus or PE (blood clots that travel to the lungs) and infections (especially in or near the wound).

Risks associated with anesthesia

During surgery, anesthesia is used to put you into an unconscious, sleep-like state. Anesthesia risks include breathing problems before or after surgery, confusion after the surgery and malignant hyperthermia (a reaction to the anesthesia that causes fever and muscle contractions). Please address any of the following conditions with your surgeon before the surgery as anesthesia risks are more common with:

What to expect with Pediatric Periacetabular Osteotomy (PAO)

PAO surgery is a commonly performed procedure but is considered a major surgery that requires anesthesia. Your surgeon will separate the muscles in the front of the hip and then cut the pelvic bone around the hip in four places where the femoral head fits into the hip socket. The next step is to realign the hipbone socket, then place screws to hold the bones in place and stabilize the joint. The incisions (cuts) will then be closed with sutures.

The procedure typically takes two to three hours to complete, and then you will rest in recovery for approximately one to two hours. You will stay in the hospital for two to four days and begin inpatient rehabilitation after two days to jumpstart recovery.

There will be restricted, toe-touch weight-bearing – the foot or toes can touch the floor for activities, like maintaining balance, but the affected leg/foot shouldn’t support any weight. You may need to be on crutches for up to six weeks after surgery.

Our goals are to help you have a normal range of motion within a week of surgery and to walk normally six weeks after surgery.

What to expect before Pediatric Periacetabular Osteotomy (PAO)

You may need to have routine bloodwork done before surgery. These tests help the doctors check your overall health and make sure there isn’t an infection present before performing the surgery. In addition, in the unlikely event (less than 5% risk) that you require a blood transfusion during the surgery, your bloodwork results will help the physicians be prepared to address that need immediately.

On the day of the surgery, please arrive with plenty of time to check in at the front desk and fill out any necessary paperwork. Your physician will provide you with specific instructions to follow and answer any of your questions beforehand.

You can’t eat or drink anything after midnight. This includes gum or candy.

What to expect during Pediatric Periacetabular Osteotomy (PAO)

The surgery will take two to three hours to complete. During the procedure, your surgeon will use fluoroscopy (continuous X-ray images displayed on a monitor) to give real-time, detailed information to improve surgical outcomes. The imaging helps guide the surgeon to cut the hip joint and the acetabulum (the bowl-shaped surface of the pelvis where the femoral head meets the pelvis) away from the pelvic bone. Then, the surgeon will rotate the acetabulum to naturally cover the femoral head and screw it into place.

If needed, the surgeon may cut the femoral head to improve the positioning, or the hip joint space may be opened. Any damage like a labral tear (when the outside rim of the hip socket is ripped) will also be repaired during the surgery.

The surgeon will close the incisions with sutures and cover them with dressings (bandages).

What to expect after Pediatric Periacetabular Osteotomy (PAO)

Observation and recovery

Once the surgery is complete, you will be moved to recovery for one to two hours for observation. After recovery, you will stay in the hospital for two to four days. The therapy team will work with you and your family to create a treatment plan and begin inpatient physical therapy two days after the surgery.

Due to anesthesia, you may feel sleepy or dizzy for a few hours after surgery. You may have a regular diet, if you don’t have an upset stomach or vomit. Stop eating or drinking if you get sick. Wait 30 to 60 minutes and then slowly sip clear liquids (Jell-O™ or water) and progress to a regular diet at your own pace. Avoid eating spicy, greasy or “heavy” foods on the first day.


Do not shower until 48 hours after the surgery – the dressings will remain on for this 48-hour time period. The dressings may become soaked with fluids after the surgery. This is normal; reinforce them with a cloth towel if they become extremely wet. After the 48 hours, you will be able to shower normally, but do not take a bath or go swimming until the sutures are removed at your first follow-up visit. Waiting to bathe reduces chances of infection and helps healing.

Pain medication

You may receive pain medications as needed for comfort, as well as anticoagulant medicines (like Heparin or Coumadin) to reduce the risk of blood clots after surgery. You will have your first follow-up visit 2 weeks after surgery, including X-rays to confirm the new positioning is accurate. At this time, the sutures are removed and replaced with Steri-Strips (small pieces of tape that will help keep the incisions closed). The Steri-Strips will fall off over time – do not remove them before they naturally come off your skin. There may be some swelling, but this will go down over the next three to four days.


During the healing process, you will have additional follow-up visits at six and 12 weeks, including X-rays to determine how you are progressing. There will be weight-bearing restrictions and you will likely use crutches for up to six weeks.

Returning to normal life

Physical therapy (PT) continues for 12 to 24 weeks (three to six months) after the surgery to ensure continued healing as new bone grows over the surgical cuts. This new bone growth will fuse the acetabulum to the rest of the pelvis, providing additional stability and increased mobility.

Most people can return to school after they no longer need to use narcotic pain medication during the day, typically within one to two weeks. You can resume sports after cleared by your physician, which usually occurs six to 12 months after surgery. If there is hip dysplasia on both sides, the second surgery will be performed separately and approximately four to six months later.

Let your doctor know if you experience severe pain that isn’t relieved by medication, or if you have a fever that’s more than 101.5 degrees and/or redness around the incision. Alert the doctor if you have increased swelling, numbness or tingling of toes. 

How do I prepare my child for Pediatric Periacetabular Osteotomy (PAO)?

You may have questions and concerns before surgery. Our goal is to make sure everyone is as comfortable as possible. We will discuss the procedure before you arrive and explain what to expect. It’s very important to tell the doctors all of the medications you are taking, including herbal remedies and over-the-counter medicines, and any known allergies. We recommend bringing medication bottles before and on the day of the surgery.

Before the procedure, the medical team places an IV needle to deliver fluids and any necessary medications. Our team is prepared to manage any bleeding or needed transfusions during or after the surgery.

What am I allowed to eat or drink before Pediatric Periacetabular Osteotomy (PAO)?

It’s important to follow the guidelines to be safe during surgery. The procedure may be canceled if you don’t follow them.

  • Do not eat solid food or drink anything after midnight on the night before surgery.
  • Gum and candy aren’t allowed.

What are the prep instructions before Pediatric Periacetabular Osteotomy (PAO)?

Arrive at the hospital two hours before the surgery to check in and allow time for the medical team to prepare for the surgery. Your care team will collect vital signs (temperature, blood pressure and oxygen levels) and mark the hip where the surgery will be performed.

We recommend bringing comforting items during the hospital stay. Also, please pack undergarments, loose-fitting shorts/pants and shirts, and sneakers or easy-to-slip-on shoes. We also encourage you to bring pillows, blankets, tablets, favorite games/DVDs and special hygiene items (shampoos/conditioners, lotions or soaps).

What questions should I ask my provider about Pediatric Periacetabular Osteotomy (PAO)?

  • Are there other treatment options for hip dysplasia?
  • What medications should I stop taking before PAO surgery?
  • Will I go home with any special equipment after PAO surgery?
  • Will I need to take prescriptions after PAO surgery?
  • How soon are families able to visit after the surgery?
  • What are the possible risks or complications during or after the surgery?
  • How long will the surgery take?

Frequently Asked Questions

  • Why did my doctor choose PAO surgery?

    Your doctor will examine the damage to the hip joint’s cartilage structures. PAO candidates have only limited damage to the structures and can flex the hips to at least 90° with minimal pain.

  • Is there an age requirement for PAO surgery?

    The earliest this surgery is performed is usually age 12 to 13.

  • What are the signs and symptoms of an infection?

    Report any of the following symptoms to your surgeon:

    • The incision site is unusually red
    • The surgery site is warm or painful to the touch
    • Fever or chills
    • There is a bad smell, pus or any drainage coming from the wound
  • What are the signs and symptoms of a blood clot?

    Signs of DVT are swelling in the leg (or arm), leg pain (like a Charley horse), red or blue skin discolorations and the leg (or arm) is warm to the touch.

    Symptoms of PE clots in the lungs are breathing problems and/or sudden shortness of breath (not related to exercise, chest pain, rapid heart rate or coughing up blood.

  • How do I take care of the incision and change the dressing?

    Your incisions may leak fluid. This is natural. Leave the dressings on for 48 hours and use a cloth towel if they become soaked.

  • How soon can I take a bath or shower?

    You can shower after 48 hours and take a bath once the sutures are removed at the first follow-up visit.

  • When do I need to have a follow-up appointment with our surgeon?

    Two weeks after surgery.