Hip Periacetabular Osteotomy (PAO)

Developed by the Swiss orthopedic surgeon, Prof. Reinhold Ganz, periacetabular osteotomy (PAO) is a surgical hip treatment used to treat hip dysplasia caused by a deformity in the acetabulum, the curved part of the pelvis that forms the socket of the hip joint. Some people with this type of hip dysplasia have symptoms from birth, but they usually become noticeable in adolescence or adulthood. Symptoms typically include pain in the hip and limited movement in this area, which can result in painful osteoarthritis if left untreated.

The PAO treatment is a type of orthopedic surgery offered at La Peer Health Systems that can help patients with hip dysplasia find lasting pain relief and restore mobility.

What Causes Hip Dysplasia of the Acetabulum?

For some with this type of hip dysplasia, the acetabulum did not fully develop resulting in a fit that is too shallow or otherwise misaligned in the socket and cannot support the femoral head (the ball shaped part of the leg bone). This misalignment puts strain on the cartilage and labrum soft tissue lining the hip socket, therefore, causing the wearing down of cartilage and further degeneration like osteoarthritis. Hip dysplasia is one of the leading causes of hip pain and arthritis in men and women less than 50 years old.

Benefits of PAO Surgery for Hip Dysplasia

For those who have hip dysplasia that has not caused advanced articular cartilage damage, periacetabular osteotomy (PAO) hip preservation surgery:

  • provides pain relief and preserves the natural hip joint.
  • prolongs or eliminates the need for total hip replacement.
  • unlike total hip replacement, PAO can allow patients much more movement post-treatment than a total replacement, and allows many patients with successful surgeries to return to normal vigorous activities like exercise and sports
  • does not prevent women from having future vaginal deliveries.

Candidates for PAO:
Periacetabular osteotomy candidates are typically 40 years of age or younger, and have a mild to moderate form of hip dysplasia in which non-surgical and other surgical treatments have failed to treat. They do not have advanced dysplasia or arthritis.

For patients who are 50 years of age or older, and have advanced osteoarthritis, a total hip replacement is typically the best option to both reduce pain and restore mobility. PAO is not considered if the hip joint space is too worn down.

What is the PAO Hip Surgery Process?

“Periacetabular” means around the acetabulum, and “osteotomy” means to cut bone. The PAO treatment process involves cutting the bone around the acetabulum to reposition the hip socket. The hip preservation surgery typically lasts about 2.5-3.5 hours, and requires a hospital stay of 3-5 days.

On the day of the treatment, patients are often given compression socks to help prevent blood clots during the surgery, and general anesthesia or regional anesthesia called an epidural catheter to ease discomfort.

A 6-7 inch incision is made over the crest of the hip to allow the surgeon to access the pelvic bone. Special cutting tools are used to cut the three bones of the pelvis surrounding the acetabulum. The acetabulum is then shifted and reoriented to allow the femoral head to fit correctly. The cut bones will fuse with the pelvis through the healing process, and two to three long screws are placed to firmly attach the acetabulum to the pelvis and ensure it stays in place.

After about 4-5 days of the surgery, most patients are able to walk using crutches or a walker without putting any weight on the treated side. Pain, bruising, swelling, numbness, tingling and popping sounds are normal following the procedure, and will typically go away within a few weeks. Pain medication is prescribed to ease any discomfort.

Combined Hip Arthroscopy and PAO for Complete Treatment

Damage to the cartilage and labrum, the soft tissue lining the hip socket, can occur over time for many patients with hip dysplasia. Hip arthroscopy is a minimally invasive hip surgery that examines the inside of the hip joint using an arthroscope. A hip arthroscopy can be performed at the same time as a PAO treatment to repair the damage and reposition the acetabulum to prevent arthritis and hip replacement.

Hip Preservation Surgery Recovery

For at least 6 weeks following the periacetabular osteotomy procedure, patients must not put any weight on the treated side. As long as there is evidence of healing, most patients are able to walk unaided 2-3 months after their surgery and resume normal weight-bearing.

Unlike total hip replacement, many patients are able to get back to sports and other vigorous activities with less pain and more mobility than before their PAO hip surgery. It typically takes between 6-12 months for patients to resume athletics.

For patients who have not developed advanced hip joint arthritis, the PAO surgery can help patients avoid osteoarthritis by 80-90%, and avoid hip replacement by 90% for at least ten years.

Contact our expert team of specialized orthopedic surgeons at La Peer Health Systems to learn more about the PAO treatment and what we can do for you.