Long-Term PAO Results Study in Japan

A recent study from Asahikawa Medical University, Japan, evaluated the intermediate to long-term results of ‘Periacetabular Osteotomy’ (cutting the bone around the acetabulum/ socket to turn it around in to a better position so as to cover the femoral head) in patients with hip dysplasia that were both younger and older than 40 years of age.[1]

The authors compared thirty-six patients (forty-one hips) who were forty years of age or older with 103 patients (117 hips) who were younger than forty years of age at the time of surgery. The mean duration of follow-up was eleven years (range, five to twenty years). Harris hip score (a functional scoring system for hip) was used for outcomes assessment.

The authors concluded that periacetabular osteotomy yielded similar results for the two groups at the time of the five-year follow-up, although the results for the older group deteriorated thereafter. Poorer results in the older group were attributed to likely decrease in physical function due to aging and increased susceptibility to progression of osteoarthritis.

Comments:

• Hip preservation (maintaining the natural hip) continues to be the mainstay of management in patients with hip dysplasia with minimal or mild arthritis.
• Periacetabular osteotomy preserves the natural hip while re-orienting the acetabulum to a better position of femoral head coverage and improves the mechanics of the hip.
• Younger patients (<40 years) seem to do better in the short term as well as longer follow-up.
• Once a patient is diagnosed with hip dysplasia it is important to discuss all options and timelines for potential hip-preservation approach prior to the onset of advanced osteoarthritic changes in the joint.

References

1. Hiroshi Ito, et al. “Intermediate to Long-term results of PAO in patients younger and older than 40 years of age” JBJS 93A:1347-54