Terminology
Some sources prefer "developmental dysplasia of the hip" (DDH) to "congenital dislocation of the hip" (CDH), finding the latter term insufficiently flexible in describing the diversity of potential complications.
The use of the word congenital can also imply that the condition already exists at birth. This terminology introduces challenges, because the joint in a newborn is formed from cartilage and is still malleable, making the onset difficult to ascertain.
The newer term DDH also encompasses occult dysplasia (e.g. an underdeveloped joint) without dislocation and a dislocation developing after the "newborn" phase.
The term is not used consistently. In pediatric/neonatal orthopedics it is used to describe unstable/dislocatable hips and poorly developed acetabula. For adults it describes hips showing abnormal femur head or acetabular x-rays.
Some sources prefer the term "hip dysplasia" over DDH, considering it to be "simpler and more accurate", partly because of the redundancy created by the use of the terms developmental and dysplasia. TYPES OF DDH include subluxation,dysplasia,and dislocation.The main types are the result of either laxity of the supporting capsule or an abnormal acetabulum.
Read more about this topic: Hip Dysplasia (human)