The Bernese periacetabular osteotomy (PAO) has become the procedure of choice for treating symptomatic acetabular dysplasia. But how long-lasting are its benefits? Quite, according to one of the largest intermediate-term follow-up studies on this procedure, authored by Wells et al. in the February 7, 2018 edition of The Journal of Bone & Joint Surgery.
Among 154 hips (average patient age of 26 years) treated with PAO at a single center between 1994 and 2008, the survival rate, with total hip arthroplasty (THA) as the endpoint, was 92% at 15 years postoperatively. When failure was defined as a conversion from PAO to THA or a symptomatic hip, the hip-preservation rate was 79% at a mean follow-up of 10.3 years.
After carefully analyzing the data to identify factors that contributed to failure or success, the authors discovered that:
- Hips with fair or poor joint congruency before surgery had 9 times the odds of failing when compared with hips that had good or excellent preoperative joint congruency.
- Hips with a postoperative lateral center-edge angle of >38° had 8 times the odds of failure.
- Hips that underwent a concurrent head-neck osteochondraplasty at the time of PAO had a 73% decrease in the odds of failing.
These data suggest that preventing excessive femoral head coverage and secondary impingement resulting from surgery improves hip survival. Consequently, Wells et al. reported that their institution, Washington University School of Medicine, “currently assess[es] for secondary impingement intraoperatively following PAO,…and, if it is present, osteochondroplasty of the head-neck junction is performed to relieve potential secondary femoroacetabular impingement.”
The authors also recommend against managing patients with symptomatic acetabular dysplasia with hip arthroscopy because “it fails to address the underlying pathomechanics found in developmental dysplasia of the hip.”