How Common is Hip Dysplasia or DDH in Babies?
1 in 10
infants are born with hip instability.
1 in 100
infants are treated for hip dysplasia.
1 in 500
infants are born with completely dislocated hips.
Hip instability is the most common newborn abnormality.
- Approximately 1 in 10 newborn infants has hip instability. That means the hips can be wiggled in the socket because of loose ligaments. Ninety percent tighten up naturally after birth.
- Approximately 1 in 100 infants will need treatment for DDH
- Approximately 1 in 500 infants has a completely dislocated hip
- A very small number of hips dislocate after the first few weeks for unknown reasons
Hip Joint Anatomy
The hip is a “ball-and-socket” joint that is held together by ligaments.
The ball is called the “femoral [fem-er-uhl] head” which is the top of the femur or thigh bone.
The socket is called the “acetabulum” [as-i-tab-yuh-luhm] and is a part of the pelvis.
The femoral head fits into the acetabulum creating the hip joint. This joint is normally held tightly in place by the surrounding ligaments and joint capsule.
Severity of Infantile Developmental
Dysplasia of the Hip (DDH)
Types of hip dysplasia
Hip dysplasia has a wide range of severity. In some children, the ligaments around the hip joint are loose allowing the hip to subluxate. This is when the ball is no longer centered in the socket. Other times the ball is slightly or completely dislocated from the socket.