Periacetabular Osteotomy (PAO): A Complete Guide

Introduction to Periacetabular Osteotomy (PAO)

Periacetabular Osteotomy (PAO) is a specialized surgical procedure designed to correct hip dysplasia, a condition where the hip socket (acetabulum) doesn’t fully cover the femoral head, leading to instability, pain, and early arthritis. Unlike total hip replacement, PAO preserves the patient’s natural joint by repositioning the socket to improve alignment and function.

Developed in the 1980s by Dr. Reinhold Ganz, PAO has become a gold-standard treatment for young, active patients with hip dysplasia. The goal is to relieve pain, restore mobility, and delay or prevent the need for joint replacement. Candidates typically include adolescents and adults under 50 who experience hip pain but have minimal arthritis.

This guide will walk you through everything you need to know—from eligibility and surgery details to recovery and long-term outcomes—so you can make an informed decision about your hip health.

Who Needs a PAO? (Indications & Eligibility)

PAO is primarily recommended for patients diagnosed with hip dysplasia, where the shallow hip socket causes uneven joint wear. Ideal candidates include:

Symptoms that may indicate the need for PAO include chronic groin or hip pain, limping, a sensation of instability ("catching" or "popping"), and difficulty with prolonged sitting or physical activity. Diagnosis involves imaging (X-rays, MRI, or CT scans) to assess socket alignment and cartilage condition.

Not everyone with dysplasia needs PAO—mild cases may be managed with physical therapy or activity modifications. A hip preservation surgeon will evaluate your anatomy, symptoms, and lifestyle to determine if PAO is the right choice.

How PAO Works: The Surgical Procedure Explained

PAO is a complex but meticulously planned surgery lasting 3–4 hours, performed under general anesthesia. Here’s a step-by-step breakdown:

  1. Incision: The surgeon makes a single incision (about 6–8 inches) over the hip.
  2. Bone Cuts: The acetabulum is carefully separated from the pelvis using precise osteotomies (bone cuts).
  3. Repositioning: The socket is rotated to a more anatomically correct position, improving femoral head coverage.
  4. Fixation: Screws hold the repositioned bone in place as it heals.

Unlike hip replacement, PAO doesn’t involve artificial implants—just strategic realignment of your natural bone. Most patients stay in the hospital for 3–5 days post-surgery. Advances in surgical techniques, including 3D imaging and navigation, have improved precision and outcomes.

PAO is technically demanding and should be performed by an experienced orthopedic surgeon specializing in hip preservation.

Preparing for PAO Surgery: What to Expect

Proper preparation can significantly impact your PAO experience and recovery. Here’s what to expect:

Pre-Surgical Evaluation: You’ll undergo imaging (X-rays, CT scans) and possibly prehab physical therapy to strengthen muscles around the hip. Blood tests and a general health check ensure you’re fit for surgery.

Home Adjustments: Prepare your living space for limited mobility post-surgery. Consider:

Day of Surgery: Follow fasting instructions (typically no food after midnight). Wear loose clothing and bring essentials (ID, insurance info, comfort items). Plan for someone to drive you home after discharge.

Mental preparation is equally important—understanding the procedure and recovery timeline helps reduce anxiety and sets realistic expectations.

Recovery & Rehabilitation After PAO

PAO recovery is a gradual process, requiring patience and commitment to rehabilitation. Here’s a general timeline:

First 6 Weeks: You’ll use crutches (non-weight-bearing or partial weight-bearing) to protect the healing bone. Pain management includes medications and ice. Physical therapy begins early to restore range of motion.

Weeks 6–12: Gradual transition to full weight-bearing as guided by your surgeon. Therapy focuses on strengthening the hip and improving gait.

3–6 Months: Most patients resume light activities (swimming, stationary biking). High-impact sports may take 9–12 months.

Rehabilitation is critical—adhering to your PT program maximizes outcomes. Full recovery varies but typically takes 6–12 months. Regular follow-ups ensure proper healing.

Risks & Potential Complications of PAO

While PAO is generally safe, all surgeries carry risks. Potential complications include:

Choosing an experienced surgeon reduces these risks. Discuss your medical history (e.g., smoking, diabetes) with your care team, as it can affect healing.

Success Rates & Long-Term Outcomes

Studies show PAO has 85–90% success rates in relieving pain and improving function for 10–20 years. Key factors influencing outcomes:

Long-term, many patients return to activities like hiking, cycling, and low-impact sports. Some may eventually need hip replacement, but PAO often delays this by decades.

Alternatives to PAO: When Is It Not the Best Option?

PAO isn’t suitable for everyone. Alternatives include:

PAO is avoided in cases of severe arthritis, poor bone quality, or inability to comply with post-op restrictions. Your surgeon will help weigh the pros and cons of each option.

FAQs About Periacetabular Osteotomy

Q: How painful is PAO recovery?

A: Pain is manageable with medications and subsides significantly within 2–4 weeks. Most describe it as "moderate" compared to joint replacement.

Q: Will I walk normally after PAO?

A: Yes! Most patients regain a natural gait after rehabilitation, though some may have slight adjustments in stride.

Q: Can PAO fail?

A: In rare cases, the hip may not heal correctly or pain persists due to advanced arthritis. Revision surgery or replacement may then be considered.