Periacetabular osteotomy is an effective treatment for adult acetabular dysplasia (DDH). This osteotomy was first reported by Dr. Ganz in 1988 and was called Bernese osteotomy (Bernese osteotomy), and in recent years, especially after 2006, it has been called Ganz osteotomy. Shandong Qianfo Mountain Hospital Joint Specialized Center Yan Xinfeng that is, Bernese osteotomy and Ganz osteotomy are the same surgical approach. The surgical approach mostly uses the iliac groin approach, which has also been modified by some doctors, and the osteotomy site of the iliac bone has also been modified by some doctors (including myself), but the essence is the same.