Hip dysplasia, developmental dysplasia of the hip (DDH) or congenital dysplasia of the hip (CDH)is a congenital or acquired deformation or misalignment of the hip joint.
The hip is a ball and socket joint. The ball, called the femoral head, forms the top part of the thigh bone (femur) and the socket (acetabulum) forms in the pelvic bone.
In some newborns, the socket is too shallow and the ball (thigh bone) may slip out of the socket, either part of the way or completely. One or both hips may be involved.
Forms of Condition :
- Bilateral Hip Dysplasia.
- Unilateral Hip Dysplasia.
The cause is unknown. Low levels of amniotic fluid in the womb during pregnancy can increase a baby’s risk of DDH. Other risk factors include:
- Being the first child
- Being female
- Breech position during pregnancy, in which the baby’s bottom is down
- Family history of the disorder
|Crowe I||Femur and acetabulum show minimal abnormal development.||Less than 50% dislocation|
|Crowe II||The acetabulum shows abnormal development.||50% to 75% dislocation|
|Crowe III||The acetabula is developed without a roof. A false acetabulum develops opposite the dislocated femur head position. The joint is fully dislocated.||75% to 100% dislocation|
|Crowe IV||The acetabulum is insufficiently developed. Since the femur is positioned high up on the pelvis this class is also known as “high hip dislocation”.||100% dislocation|