Valerie M. Kemo, RN, CCM, CMAC
Developmental dysplasia of the hip (DDH), also called Congenital hip dislocation (CHD), is a condition of the hip joint resulting from poor development of the hip joint during fetal development. The National Institute of Health (NIH) reports that this condition affects approximately 1 in 100 infants. The condition can result in dislocation of the hip and, without early identification and treatment, result in long term complications including pain, loss in function and mobility, and early onset arthritis.
The Hip Joint Anatomy, Development, and Function
The hip is a ball and socket joint where the head (ball) of the femur or thigh bone is securely seated in the acetabulum (socket) portion of the hip bone. The hip is a complex joint that begins to develop in weeks 4-6 of fetal development and is fully developed by week 11. Functionally, the hips are responsible for carrying the weight of the body’s trunk, body stabilization, and lower limb movement including flexion, extension, rotation and moving the leg away (abduction) and toward (adduction) the body.
In a normal hip joint, the head of the femur fits snugly within the socket of the joint. In DDH, the socket portion of the joint is too shallow for secure placement of the head of the femur. The severity of the condition can vary but can result in hip instability, looseness, or joint dislocation.
Causes of DDH
The cause of DDH is unknown, however there are some common factors that may put an infant at risk:
Females are 2 to 4 times more likely to develop CHD
A family history of CHD
First born children
Low levels of amniotic fluid
Breech or bottom first position at birth
Tight blanket swaddling
Symptoms and Diagnosis of DDH
The symptoms of DDH can vary depending upon the time of diagnosis of the condition. Children are routinely evaluated for DDH at birth and at visits throughout the first year of life. In the first 3 months, the provider tests the hip joint through movement and manipulation. Joint looseness, clicking or popping would be considered positive signs. Beyond 3 months of age, one leg may be shorter than the other, the child may limp, there may be uneven folds on the legs or buttocks, or delayed crawling or walking. Any of these symptoms may prompt the provider to pursue further testing including imaging studies such as ultrasound or x-rays and consultation with an orthopedist.
Treatment of DDH
Typically, the child will be referred to an orthopedist that specializes in the treatment of DDH. They will evaluate the child, implement a plan, and follow their progress through x-rays or other imaging. Pediatric specialty facilities also offer comprehensive DDH programs, staffed with clinical experts, that allow for the comprehensive planning and treatment of a child with this condition.
Treatment of DDH depends on the severity of the condition and the age of the child at the time of diagnosis. Infants that are diagnosed at birth up to 6 months of age are commonly placed in a Pavlik Harness. A Pavlik Harness is a soft bracing device that looks similar to a skydiving harness. The harness pulls the child’s legs apart and keeps their knees and hips in a bent position (think frog legs position). This positioning allows for the hip ligaments to strengthen and the socket to better form around the ball portion of the joint. The harness is generally worn between 6 and 12 weeks, either full or part time. The Pavlik Harness is found to be up to 90% effective in the treatment of DDH.
If the harness is unsuccessful or the child is diagnosed when older, they may try other bracing devices or recommend surgery. The type and complexity of the surgery are, again, based upon the severity of the condition. Casting is often required after surgery to allow for correct positioning and healing.
Complications of DDH
Untreated, DDH may result in:
Pain
Dislocation of the hip
Weakness of the muscles and tendons around the joint resulting in an unstable hip joint
Labral tears (a tear of the protective covering of the socket joint)
Osteoarthritis that can result in the need of a hip replacement
DDH, like other health conditions, responds well to early identification and treatment. If you or your child have a risk factor for DDH, tell your pediatrician or health care provider during your pregnancy and ensure that the child is evaluated at the time of birth. If your child develops symptoms of DDH after birth, talk to your pediatrician or health care provider so that they can perform appropriate evaluations to ensure early treatment.
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Assessed and Endorsed by the MedReport Medical Review Board