Developmental dislocation of the hip(DDH) is the most common disease in pediatric orthopedics, acetabular dysplasia, nonconcentric hip-joint articulation and approximate femoral deformity are the main pathologic morphology abnormality.

• 发育性髋关节脱位是小儿骨科最常见的先天性畸形之一，髋臼发育不良、股骨头脱位和股骨近端改变是髋关节脱位的主要骨性病理变化。