Periacetabular Osteotomy

What is a Periacetabular Osteotomy (PAO)?

A periacetabular osteotomy (PAO) is a joint-preserving operation used to treat hip dysplasia in younger patients with a well-preserved hip joint. In dysplasia, the acetabulum (the socket of the hip) is too shallow or poorly oriented to adequately cover the head of the femur (the ball), concentrating load over a small area and predisposing the hip to labral tears, cartilage damage, and early arthritis.

“Periacetabular” means “around the acetabulum,” and “osteotomy” means a controlled cut in the bone. In a PAO, a series of precise cuts is made around the socket to free it, allowing it to be repositioned to provide better coverage of the femoral head. The repositioned socket is then secured in its new, improved position. The goal is to distribute load more evenly across the joint, relieve symptoms, and reduce the risk of early arthritis — preserving the patient’s own hip rather than replacing it.

Who is Suitable?

PAO is considered for carefully selected patients, typically:

• Younger patients (often adolescents and adults) with symptomatic hip dysplasia
• A hip joint that is still well preserved, with healthy or minimally affected cartilage
• Good range of motion
• Symptoms attributable to the dysplasia

PAO is generally not appropriate where the joint already has significant arthritis, as joint preservation is less likely to succeed once the cartilage is substantially worn. Careful assessment, including detailed imaging, determines suitability. The most appropriate option for you will be discussed at your consultation. (See also the Adolescent Hip Dysplasia and Hip Preservation Surgery pages.)

The Procedure

PAO is a complex, specialised procedure. A series of controlled cuts is made in the pelvis around the acetabulum to free the socket, which is then rotated into a position that better covers the femoral head and improves load distribution. The repositioned bone is held in place, typically with screws, while it heals. In some cases, problems inside the joint such as a labral tear may also be addressed. Surgery is performed under anaesthesia and is a significant operation requiring specialised expertise.

Recovery

Because PAO involves healing of the repositioned pelvic bone, recovery is a substantial and staged process. It typically involves a period of protected weight-bearing using crutches while the bone heals, followed by a progressive rehabilitation programme to restore strength, movement, and function over a number of months. Bony healing and return to full activity take time, and your specific recovery plan will be explained in detail and tailored to your progress.

Risks and Complications

As a major, specialised procedure, PAO carries risks, including:

• Infection
• Blood clots (deep vein thrombosis or pulmonary embolism)
• Bleeding
• Injury to adjacent nerves or blood vessels
• Delayed healing or non-union of the bone
• Issues related to the fixation (such as prominent screws)
• Incomplete correction or ongoing symptoms
• Progression to arthritis over time in some patients

All relevant risks will be discussed in detail at your consultation.

Frequently Asked Questions

What is the goal of a PAO?

The goal is to reposition the shallow or poorly oriented hip socket to provide better coverage of the femoral head and distribute load more evenly. This aims to relieve symptoms and reduce the risk of early arthritis, preserving the patient’s own hip rather than replacing it.

Who is a PAO suitable for?

PAO is generally suited to younger patients with symptomatic hip dysplasia and a well-preserved joint. It is usually not appropriate once significant arthritis has developed. Detailed assessment and imaging determine whether it is the right option for you.

How long is recovery after a PAO?

Recovery is a substantial, staged process. It typically involves a period of protected weight-bearing while the bone heals, followed by progressive rehabilitation over a number of months. Full bony healing and return to activity take time, and your plan will be tailored to your progress.

Medical Disclaimer
The information on this page is intended as general patient education and does not constitute medical advice. Every patient is different, and treatment decisions should always be made in consultation with a qualified medical professional based on your individual circumstances, health history, and imaging. Outcomes from surgery vary between patients and cannot be guaranteed. If you have concerns about your hip health or are considering surgery, please contact Dr Slattery’s rooms to arrange a consultation.