PAO of the hip – periacetabular osteotomy for hip dysplasia

In hip dysplasia, the hip socket is too shallow or positioned too steeply. As a result, the femoral head is not adequately covered. Body weight bears down on an area at the edge of the socket that is too small. This overloads the labrum and cartilage and often causes a feeling of instability. Without treatment, osteoarthritis can develop at an early stage.

A PAO may be considered when

• hip dysplasia has been confirmed on an X-ray,
• you have symptoms that restrict your everyday life or sporting activities,
• the articular cartilage is still largely intact, meaning that there is no advanced osteoarthritis.

Age alone is not a reason for exclusion. A PAO can also produce very good results beyond the age of 30 or 40 if the cartilage is still healthy. We have published our own data on this. If osteoarthritis is already advanced, joint replacement is usually the better solution, and we offer this too.

During a PAO, the hip socket is released from the pelvis using several targeted bone cuts around the joint, rotated into the correct position and fixed with screws. The femoral head is then properly covered again and the load is distributed over a large area.

One decisive advantage over older procedures such as triple pelvic osteotomy is that the posterior column of the pelvis remains intact during a PAO. The pelvis remains stable and the birth canal is not altered.

• Standing up: on the day of the operation
• Hospital stay: 3 to 5 days
• Weight-bearing: 6 weeks of partial weight-bearing at 15 kg using forearm crutches
• Flexion: do not bend the hip beyond 90° for 6 weeks; actively lift the leg only after 6 to 8 weeks
• Exercise bike: from week 3 once the wound has healed, without resistance and with a high saddle; the operated leg is moved only passively
• X-ray check: after 6 weeks
• Full weight-bearing: usually from week 7 to 8
• Driving: after 8 to 10 weeks

We plan your return to work and sport individually with you, depending on your occupation, your sport and how the bone is healing.

Every operation carries risks. PAO is a major pelvic procedure, but it is safe in experienced hands. At major centres, the rate of serious complications is now approximately 1%. Higher rates can be expected at hospitals performing few PAOs each year.

• Bleeding: This comes mainly from the bone and can cause bruising. Of around 2,000 PAOs performed in Greifswald, only one has required a blood transfusion to date.
• Nerve damage: The literature reports damage to the sciatic nerve or femoral nerve in approximately 2% of cases; our rate is 0.4%.
• Sensory nerve on the outside of the thigh (lateral femoral cutaneous nerve): Numbness is common and usually resolves. A burning nerve pain (meralgia paraesthetica) rarely develops. This must be treated very quickly; please contact us immediately if it occurs.
• New bone formation in the soft tissues (heterotopic ossification): With our minimally invasive technique, we now practically no longer see this.

If a complication does occur, stay in contact with us. We will coordinate everything else, and many of those affected still achieve a good result after a little more time.