Developmental dysplasia of the hip (DDH)
The hip is a “ball-and-socket” joint. In a normal hip, the ball at the upper end of the thighbone (femur) fits firmly into the socket, which is part of the large pelvis bone. In babies and children with developmental dysplasia (dislocation) of the hip (DDH), the hip joint has not formed normally. The ball is loose in the socket and may dislocate easily.
Causes & Risk Factors
Although DDH is most often present at birth, it may also develop during a child’s first year of life. DDH tends to run in families. It can be present in either hip, but usually affects the left hip. DDH is most common in:
- First-born children
- Babies born in the breech position (especially with feet up by the shoulders). The American Academy of Pediatrics now recommends ultrasound DDH screening of all female breech babies.
- People with a family history of DDH (parents or siblings)
- Babies that had low levels of amniotic fluid in the womb
Symptoms & Types
Some babies born with a dislocated hip will show no outward signs of the condition. Contact your pediatrician if your baby has:
- Legs of different lengths
- Uneven skin folds on the thigh
- Less mobility or flexibility on one side
- Limping, toe walking, or a waddling, duck-like gait
In all cases of DDH, the socket (acetabulum) is shallow, meaning that the ball of the thighbone (femur) cannot firmly fit into the socket. Sometimes, the ligaments that help to hold the joint in place are stretched as well. The degree of hip looseness, or instability, is different in each child with DDH.
Dislocated - In the most severe cases of DDH, the ball of the thighbone, which is also called the head of the femur, is completely out of the socket. Dislocatable - In these cases, the ball of the thighbone lies within the socket, but can easily be pushed out of the socket during a physical exam. Subluxatable - In mild cases of DDH, the ball of the thighbone is loose in the socket. During a physical examination, the bone can be moved within the socket, but it will not dislocate out of the socket.
Diagnosis & Tests
A physical exam and ultrasound or X-rays are used in making a diagnosis.
Treatment & Care
Treatment for DDH depends on when the child is diagnosed. Braces, casting and surgery are all options for treatment.
Living & Managing
After treatment is complete, most children are able to resume normal activities.