Developmental Dysplasia of the Hip
Developmental Dysplasia of the Hip or DDH occurs when the ball and socket hip joint fails to develop correctly.
Essentially, with DDH, the hip socket fails to develop correctly, so let’s look at this:
The ball of the hip socket is called the “femoral head” and is at the top of the femur or thighbone.
The socket is called the “acetabulum” and this is a part of the pelvis.
Ligaments, muscles and a joint capsule hold them together and promote growth and strength.
In a normal, healthy hip, the head of the femur is smooth and round and the acetabulum is a smooth cup-like shape and the two sit together like an egg in an egg-cup.
DDH occurs when the two don’t fit snugly together and whilst no two cases are the same, there are three degrees of severity.
The main elements to be aware of are:
- If the ball is not held in place securely this can indicate a shallower than average socket; this is called acetabular dysplasia
- A shallow socket can create an unstable joint which means the ball may slide in and out of the socket, this is called a dislocatable or subluxatable hip
- If the ball simply has no contact with the socket and stays outside the joint, it is called a dislocated hip