Your grandson may have a condition known as developmental dysplasia of the hip (DDH), previously known as congenital hip dysplasia. This is a common disorder affecting infants and young children. The change in name reflects the fact that DDH is a developmental process that occurs over time. It develops either in utero (in the uterus) or during the first year of life. It may or may not be present at birth.
In this condition there is a disruption in the normal relationship between the head of the femur (thigh bone) and the acetabulum (hip socket). DDH can affect one or both hips. It can be mild to severe. In mild cases called unstable hip dysplasia, the hip is in the joint but easily dislocated. More involved cases are partially dislocated or completely dislocated. A partial dislocation is called subluxation.
Mild cases are treated with double or triple diapering. This forces the hips into a position of flexion and abduction (legs apart). When the hips are in this position, the head of the femur is directed more into the socket and kept there. The pressure of one bone against the other helps form the socket more fully.
Compliance with the diapering routine is important. If given enough time, the hip socket can be helped to form as it should with this method. It may take several weeks to several months to get the desired results. The pediatrician will follow the baby closely and let the parents know when it is safe to go back to single diapering.
If this approach isn’t successful, it may be necessary to use a special harness called a Pavlik harness. This padded sling puts the baby into the desired position of hip flexion and abduction. For babies under the age of six months, this technique can be quite effective. Reduction (restoring the natural position of the hip) can occur as quickly as one to two weeks.