What is developmental dysplasia of the hip?
Developmental dysplasia of the hip (DDH) refers to a problem with the shape of the hip that leads to instability of the joint.
The hip is a ball and socket-shaped joint made up of two parts: the top of the thighbone (the femoral head) and the socket (the acetabulum). The top of the thigh bone is normally round and sits inside the hip socket. Children with DDH, or hip dysplasia, have very misshapen or shallow hip socket bones that are not deep enough to completely cover and support the top of the thigh bone.
What are the types of developmental dysplasia of the hip?
DDH ranges in severity from acetabular dysplasia (mild changes in the shape of the socket) to hip subluxation (the top of the thigh bone is loose in the socket) to dislocatable or unstable hip (the top of the thigh bone can come out of the socket when stress is applied) to the extreme of a completely dislocated hip (meaning the top of the thigh bone is out of the socket).
Who gets hip dysplasia?
The actual causes of DDH are still unknown; however, it seems that hip dysplasia is a developmental problem. It can occur before birth, after birth and less often during infancy. There are several recognized risk factors for hip dysplasia:
- A family history of hip problems
- Being the first-born child
- Female (versus male) gender
- Babies who are born in the breech position (especially with feet up by the shoulders)
Resources for hip dysplasia: