Understanding Developmental Dysplasia of the Hip
Developmental dysplasia of the hip, also known as 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.

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?
Your babys’ hips are usually checked at birth and at 68 weeks as part of your national health screening pathway. 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
• 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 68 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 visit our website www.stepsworldwide.org.

Regular checkups 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.