Understanding Developmental Dysplasia of the Hip
Developmental dysplasia of the hip (DDH) is when the ball shaped part of the end of the thighbone and the socket do not fit correctly together. There are varying levels of hip dysplasia, from mild to severe.
If the ball (femoral head) is not held correctly in place, the socket (acetabulum) may be more shallow than usual. Sometimes this makes the joint less stable and the ball may slide in and out of the socket. This is called a dislocatable or ‘subluxatable’ hip. If the ball loses contact with the socket and stays outside the joint it is called a dislocated hip. One or both hips may be affected.
About 1 or 2 in every 1,000 babies has a hip problem needing treatment. In fact, many more babies (about 6%) will have immature hips that will get better without treatment. With DDH, the problem persists, needing early diagnosis to help reduce the severity and length of time needed for treatment.
For a guide to Baby Hip Development please download our BMA (British Medical Association) award winning FREE Baby Hip Health leaflet for more detailed information.
DDH can happen to any baby but some factors make the condition more likely.
The two most important risk factors are:
• a baby born by breech or who was in the breech position in the last three months of pregnancy
• a close family history of DDH or hip problems that came on in early childhood.
• DDH is more common in first pregnancies and in baby girls
In more than half of cases, however, there is no identified risk factor and the cause is unknown.
Things that could hinder normal hip development are; tight swaddling or spending long periods of time in car seats. Anything that pulls the hips straight or restricts their natural movement should be avoided.
How is DDH detected?
ALL babies’ hips are checked at birth and at 6-8 weeks as part of a national screening programme called the Newborn Infant Physical Examination (NIPE). The baby’s hips are gently manipulated to see if they are correctly in joint by tests known as the Ortolani and Barlow Tests.
Even if the physical examination is normal NHS guidelines say that your baby’s hips will have an ultrasound examination within 6 weeks if the following applies:
• there is a history of early childhood hip problems in your family or
• your baby was in the breech position: around 36 weeks of pregnancy even if the baby turned for head first delivery.
• born before 36 weeks in a breech position.
• in a multiple birth, if any of the babies is in either of the groups above, every baby should have an ultrasound examination.
The physical examination is not 100% accurate as this only detects hip instability at the time of the examination. This means that some babies might appear to be normal at the tests but develop problems later or that DDH has not been picked up at the initial examination. As routine hip examinations finish after the 6-8 week check, family members are best placed to identify a problem.
Early diagnosis gives the best chance for effective treatment. The condition becomes more difficult to treat as child gets older and there is a risk of developing arthritis of the hip at a young age.
Possible signs of DDH include;
• Deep unequal creases in the buttocks or thighs
• When changing a nappy one leg does not seem to move outwards as fully as the other or both legs seem restricted
• The child drags a leg when crawling
• One leg looks longer than the other
• A limp (if one leg is affected) or a ‘waddle’ if both hips are affected
The child is unlikely to feel pain even if displaying these symptoms.
How is DDH treated?
From birth to six months, babies with developmental dysplasia of the hip are usually fitted with a special fabric harness, the most common types being the Pavlik harness or the Van Rosen Splint. The type of harness will vary, depending the treating hospital. Studies have shown that the best time for this treatment is between the ages of 6 to 12 weeks. The harness needs to be worn for several weeks and in most cases this will correct the condition.
For more information about the Pavlik harness please download The Parents’ Guide to caring for a child in a Pavlik Harness.
Regular check-ups and ultrasound scans are necessary to check the fit of the harness and the progress of treatment.
For some children, when a splint has not worked or DDH is not diagnosed until after six months old, surgery may be required.
The BMA ‘Highly Commended’ Steps publication Hip Surgery and Spica Cast Care explains the different procedures that may be required and gives practical advice about life with a spica cast. The booklet also includes information about communicating with doctors, going into hospital, cast and wound care and practical hints and tips. Steps have also produced a guide to help parents and carers prepare themselves and their child for a hospital admission.
Offer helpful advice on day to day life in a spica cast. Further film clips on caring for an older child in hip spica can be found on our YouTube Channel.
Steps has compiled a list of items and equipment recommended by other DDH parents that may be useful when caring for a child in a hip spica cast.