Developmental Dysplasia of the Hip (Pediatric)
What is developmental dysplasia of the hip?
Developmental dysplasia of the hip (DDH) is a condition in children in which the bones of the hip joint do not form or grow together properly. A hip dislocation happens when the ball (or head of the thigh bone) of the hip joint slips out of the socket (the pelvis).
What causes developmental dysplasia of the hip?
It generally occurs while the child is still a developing fetus, but can occur, more rarely, in early childhood as well. The ligaments of the hip joint may be too loose or stretched and as a result the hip socket does not develop as deeply as is needed for a normal hip.
Risk factors include being female, the first born, breech presentation at birth and a family history of hip dysplasia.
How is developmental dysplasia of the hip diagnosed?
The baby’s hips are checked by the pediatrician at birth and during all well child visits up to about 6 months of age and sometimes longer. If there is concern at birth then the baby is usually checked again 2 weeks later with a physical exam. If there continues to be a concern such as a difference in the length of the two legs, the skin folds on the back of the thigh are uneven from side to side or difficulty moving the leg away from the body on one side, then the baby will be referred to a pediatric orthopaedist and will get an ultrasound of the hips done.
There are usually no major symptoms of DDH, because it is often detected in infants soon after birth and treated without complications, but if an older child starts to toe walk on one side or limp then they should be checked for a hip problem.
How is developmental dysplasia of the hip treated?
If untreated, the joint may become dislocated, in which the ball sits completely outside of the socket. This instability may cause osteoarthritis in the joint, leading to a painful limp at a relatively young age.
There are a variety of treatments available for DDH, and the most important determinant in selection of the appropriate treatment is age of the child. All methods are designed to position the hip together more appropriately and enhance the stability of the joint in the future
If DDH is detected soon after birth, the newborn will be placed in a Pavlik harness, a simple device that is strapped around the child’s legs and shoulders. It is designed to keep the legs in the proper position for the hip joint with the ball snugly in the socket, so that the socket develops normally. The Pavlik harness is usually worn for up to 3 months, and is surprisingly soft and comfortable. Your pediatric orthopaedist will tell you if the Pavlik can be taken off for bathing. The baby’s development is not affected by using the harness.
In some children the hip does not immediately normalize even with a Pavlik harness. A procedure is then done in the operating room to get the hip in the proper position and the child is then placed into a spica cast. The spica is generally kept on for 6 weeks and then replaced with a new cast in the operating room. That second cast is kept on for an additional 6 weeks for a total of 12 weeks with the cast.
Every child is different and the time spent in the Pavlik harness or spica cast may vary based on the ultrasound imaging or x-rays.
Coping with DDH
DDH in a child can be a difficult condition for some parents to deal with, particularly because their child is usually completely healthy, with often normal-looking legs and hips. Therefore, for children who must wear a cast or receive surgery, the treatment may seem somewhat extreme. However, it is important to remember that such measures greatly enhance a child’s future health and prevent what could otherwise be a debilitating condition. The vast majority of children with DDH does well with treatment and have full walking function at a normal age. Most are not at all limited in the activities in which they participate, such as games or competitive sports. Therefore, although the condition may present some hurdles early in a child’s life, early detection and adherence to the proper treatment regimen will allow your child to be active and healthy through childhood and into adolescence and adulthood.