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Periacetabular Osteotomy (PAO)

What is Periacetabular Osteotomy (PAO)?

Periacetabular osteotomy (PAO) surgery is used to treat hip dysplasia. It is also used to treat instability of the hip.

  • Peri means “near”
  • Acetabular refers to the acetabulum, or the hip socket
  • Osteotomy means surgery done on a bone

Hip dysplasia and instability of the hip can cause a lot of pain. People with these conditions might not be able to walk or move well. Your doctor may call this restricted mobility.

People of any age can have these conditions. PAO surgery at Cincinnati Children’s is done in patients ages 12-45. For success with this surgery, the growth plates of the hip socket are typically almost closed. That most often happens at the beginning of the teen years.

A surgeon may suggest PAO surgery to:

  • Treat dysplasia
  • Increase stability of the hip
  • Treat impingement of the hip
  • Reduce pain
  • Prevent or delay the need for a total hip replacement

The goal of surgery is to reduce pain and restore function. Another goal is to give patients the ability to move their hip easily again. This surgery often allows patients to live a healthy, pain-free life.

Before Periacetabular Osteotomy (PAO) Surgery


After you meet with a surgeon, imaging will be ordered. This includes any or all of the following:

Your surgeon will review the results with you. They will let you know if they feel PAO surgery will be helpful.

Hip Conference

Sometimes there is a question about whether PAO surgery will be a success. When that happens, your surgeon will go over your case during our “hip conference.” Your case will be discussed with:

  • The Division of Orthopaedics director
  • Two co-directors of our Hip Preservation Program
  • A joint replacement surgeon
  • Clinical nursing staff
  • Lead radiologist

The goal of this meeting is to cover all aspects of your case. Topics include your age, lifestyle, and expectations of and after surgery. We want to make sure that everyone, including the patient and family, agrees that PAO surgery is right for the patient.

Pre-Op Consultation

Once surgery is scheduled, there will be a pre-op visit. At that visit the nurse will go over what you need to know before, during and after surgery. The nurse is available by phone and email if you have questions or concerns any time before or after surgery.

Pre-Op Physical Therapy Visit

You will also have a pre-op physical therapy visit. At this appointment, you’ll learn what to expect as you recover after surgery. The therapist will talk to you about:

  • Home exercise after surgery
  • Precautions to take after surgery
  • Any post-operative equipment needs

During Periacetabular Osteotomy (PAO) Surgery

What to Expect

The surgery will take about four hours. At Cincinnati Children’s, two experienced attending surgeons perform this surgery together.


For pain control, you will receive a nerve block. This type of anesthesia uses a medication to numb a specific area of nerves in order to block pain. Using a nerve block (rather than an epidural) has been shown to decrease the length of a patient’s stay in the hospital. This also decreases pain medication needs after surgery.

The Procedure

The hip joint includes a ball (at the top of the femur, or thigh bone) and socket (in the pelvis). Hip dysplasia occurs when there is a problem between the ball and socket. During a PAO surgery, your surgeon will make several cuts in the bones of the hip joint. The goal is to improve the direction and/or amount of coverage the socket provides for the ball. Screws are used to hold the bones in their new position. While you heal, new bone will grow and allow your hip joint to line up correctly.

After Periacetabular Osteotomy (PAO) Surgery

What to Expect

  • You’ll be in the hospital for two to three days.
  • During that time, you’ll see specialists from Orthopaedics, Pain Management and Physical Therapy / Occupational Therapy.
  • You will be on crutches for six to eight weeks.

Post-Op Appointments

  • Two weeks post-op: At this visit, your surgeon will check your incision. Your dressing will be taken off. An X-ray of the hip will also be completed.
  • Six weeks post-op: At this visit, you will have an X-ray of your hip joint. The surgeon will check to make sure you are healing well.

Physical Therapy

To allow the hip to heal, patients do not start physical therapy until six weeks after surgery. Sometimes physical therapy begins earlier depending on a patient’s individual needs.

Most patients go through six to nine months of physical therapy after PAO surgery. Physical therapy will help:

  • Wean you off crutches
  • Work on your range of motion and hip strength
  • Get you back to your normal level of activity

Your therapist and surgeon will watch your healing and will clear you for certain activities as you make progress. Most patients are able to return to normal daily activities within 4½ to six months after surgery. Return to sports often happens six to nine months after surgery depending on the level of desired competition.

Our Hip Preservation team has created physical therapy protocols for PAO patients to follow. You will be able to take these protocols with you if you have traveled from out of town for surgery. Your therapist may contact our therapists for assistance.


After recovery from PAO surgery, patients have less or no hip pain. They are able to move and walk better than before surgery.

Last Updated 10/2023

Reviewed By Tonjia Kramer, RN

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