Problems affecting the hip joint, ranging from mild looseness to dislocation
- Present at birth
- More common in girls
- Sometimes runs in families
- Rarely persists in babies who are carried astride the mother’s back
Developmental dysplasia of the hip (DDH) is a term that covers a range of problems with the hip joint in the newborn. In mild cases, the hip joint moves excessively when manipulated. In moderate cases, the head of the femur (thighbone) slips out of the hip socket when manipulated but can be eased back in. In severe cases, the dislocation is permanent, and the head of the femur lies outside the hip socket.
Mild cases may be the result of loose ligaments, but in severe cases, the dislocation is related to abnormal development of the hip socket. DDH occurs more often in the left hip and rarely affects both hips. About 1 in 500 babies is affected. Carrying a baby astride the mother’s back may correct mild DDH. DDH is more common in girls and in babies who are born in the breech position. It may also be associated with clubfoot.
The cause of DDH is not fully understood. In about 1 in 5 babies affected, there is a family history of hip dysplasia, suggesting a genetic factor. It may also be due to the effect of maternal hormones that relax the mother’s own ligaments in preparation for labour.
What are the symptoms?
Mild forms of DDH may have no symptoms. In severe cases, the symptoms may include:
Asymmetrical creases in the skin on the backs of the baby’s legs.
Inability to turn the affected leg out fully at the hip.
Shorter appearance of the affected leg.
Limping when older.
If DDH is not corrected early, it may lead to permanent deformity and to the early onset of the joint disorder osteoarthritis.
What might be done?
The doctor will check your baby’s hips for stability and range of movement shortly after birth and then regularly at routine checkups until your child is walking normally. If your doctor suspects DDH, he or she may arrange ultrasound scanning to confirm the diagnosis.
The less severe forms of DDH often correct themselves during the first 3 weeks of life. However, if the problem persists, prompt treatment is essential because the head of the femur must be positioned correctly if the socket is to develop normally. In a very young baby, the hip joint may be positioned in a harness for 8–12 weeks to hold the head of the femur in the hip. In an older baby, the hip may need holding in a cast for up to 6 months to correct the problem. If treatment is unsuccessful, surgery may be necessary to correct the hip dysplasia.
If DDH is diagnosed early and treated immediately, most babies develop normal hip joints and there is no permanent damage.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.
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