Nobody knows what causes them. What we do know is that they are more common in girls than in boys, more common in children who were born feetfirst, and more common in children whose other family members have the condition. We also know that early detection makes dysplasia easier to treat. In this country, evaluation of the hips is an important part of examining newborns. Any hint of a click or a clunk during gentle maneuvers of a relaxed baby's joints demands a call to an orthopedic surgeon.
Treatment is usually a simple harness of straps that hold an infant's hips flexed and separated.
Within about six or eight weeks, the ligaments surrounding the hip tighten up for good. I had no way of knowing what Gabrielle's examination had been like when she was a newborn. If the head of the femur had been completely out of the socket at birth, her bones would have been much more deformed. Most likely, Gabrielle had been born with slightly loose ligaments in her hips. As she began to walk, and especially after she grew taller and heavier, the increasing pressure on her hip joint would have caused the ball of the femur to start slipping out of place.