Q: My neighbor just had a baby, and I was told that the baby had dislocated hips. I am aware that animals can get hip dysplasia, but does this really happen in people? If so, how does it happen? Will the baby be okay?
A: Congenital dislocation of the hips (CDH) is a condition in which the head of the upper leg bone (femur) does not fit properly into the hip socket. It occurs in approximately 1 in every 1000 births, it is more common in females newborns (70%), and it is twice as likely to occur in the left hip.
Most cases of CDH represent a deformity that is acquired during the latter stages of pregnancy. The exact causes are not known, however, there are different mechanical factors that may predispose to CDH.
Due to intra-uterine crowding during the last trimester of pregnancy, there is more hip flexion of the fetus which causes increased stretching of the ligaments of the hips. This might explain why the incidence of CDH is greater in first time pregnancies. In subsequent pregnancies the uterus is more relaxed and easily stretched, thus giving the fetus "more room".
Breech pregnancies also have a higher than normal rate of CDH, and this might be because in the breech position the fetus has been subjected in utero to prolonged hip flexion and stretching which can lead to the CDH.
It may also be possible that the mother's hormones of pregnancy (estrogen etc.) cause an increased laxity of the hip joint ligaments leading to CDH. This is still somewhat controversial at this time.
The diagnosis can, and should be made in the newborn period...ideally while the baby is still in the hospital nursery. The examining doctor ranges the hips through a couple of different maneuvers. If the hip is dislocated a click will be felt. Other signs of CDH include an asymmetry of the skin folds of the legs, one leg appearing shorter than the other. These are very subjective findings and are more difficult to discern.
CDH can be confirmed by x-ray, and/or ultrasound. The reliability of these tests depends entirely on the experience of the doctors interpreting the results
If detected early, the treatment of CDH is conservative and very successful. There is a Velcro harness, called a Pavlik harness, that the baby wears to keep the knees and hips flexed. This spreads the hips apart enough to insure proper positioning of the femur and hip joint. In young infants (under 6 months), this method has an over 90% success rate in treating CDH. The length of time that an infant will need to wear the harness depends on a number of factors, but it varies from 4-12 weeks.
The real key to CDH is early detection and treatment. If not picked up in early infancy, the results can be far less from optimal. These patients may require traction or even surgery...and may still have permanently damaged hips. If you have any questions about CDH in a family member, check with your doctor immediately, and resolve this as soon as possible.