Lessons learned after more than 250 periacetabular osteotomies.

The Bernese periacetabular osteotomy (PAO) has become the procedure of choice in many centers for the treatment of young patients with symptomatic hip dysplasia in the absence of severe secondary arthrosis. This article concerns our institution's "learning curve" with this procedure and focuses on patient selection, exposure, technical aspects of performing the bone cuts, mobilizing the fragment, and obtaining proper correction.