Developmental dysplasia of the hip (DDH) describes a variety of conditions in which the ball and socket of the hip do not develop properly.

The hip is a 'ball and socket' joint. Normally the top of the thigh bone (femur) has a round ball shape which fits into a cup like socket on the pelvis (acetabulum). There are a range of developmental hip conditions that can affect babies.

In the mildest forms, the socket may fail to grow deep enough. In the more severe forms, the femoral head or ball may be displaced completely out of the socket and be dislocated. In the past this was known as a congenital dislocated hip (CDH).

Why does it happen?

One or two babies in every hundred are born with some kind of hip problem. It can happen to any baby, but the following factors may contribute:

Breech birth or breech position in the last three months of pregnancy

A family history of hip problems or double jointedness

Lack of fluid surrounding the baby in the womb (oligohydramnios)

The increase in maternal hormones before delivery may make the susceptible baby's hip more likely to displace at the time of birth

Wrapping a baby's legs too tightly after birth

Girls are more often affected than boys, particularly the first born

Hip problems are more common in babies who have mild foot deformities or tightness in the neck

How is it detected?

The hips of all babies are examined in the first few days after birth by gently rotating the legs. If there appears to be excessive movement in the joint they will be classed as unstable and depending on the severity of the instability the baby will be treated or asked to come back for a further examination in a few weeks.

Between 2 to 4 weeks of age the baby may undergo an ultrasound examination. This is a non invasive procedure that is very similar to the ultrasound used in pregnancy. It helps the doctors to obtain an accurate image of the hips so that they can check on the development of the joint. After about 6 weeks of age an x-ray may be taken. Routine developmental checks should also test for hip problems and the signs to look for in the older child are unequal creases in the buttocks or thighs, difficulty in spreading the legs, inequality in leg length or abnormal gait.

Does DDH hurt?

Even though as parents you may be distressed at discovering your baby has a hip condition, your baby will not find the condition painful, although he or she may strongly object to being examined.

How will I cope?

When a diagnosis of hip problems is first made, you may well experience an emotional reaction. Every parent responds differently but other parents have experienced fear, resentment and anguish to varying degrees. This is a natural reaction when a condition such as hip problems affects one you love. But many, many, children have been affected in the past and there are lots of other parents who have been in the same situation and seen their children grow up to lead full, active lives.

Is treatment necessary?

Some babies may grow out of a mild instability without treatment, but at the moment there is no way to tell which hips will come right on their own. So all babies who have been diagnosed as having a hip problem will be closely monitored and some will be offered treatment if it is clear their instability is not getting better on its own. Without treatment, the growth of the hip may be affected and there will be a much greater risk of developing osteoarthritis.


What does the treatment involve?

If the condition is detected around the time of birth, a lightweight splint which holds the legs apart (abducted) may be applied. This position aids the correct growth of the ball and socket joint.

The splint is worn for several weeks and is only removed at the clinic. In milder cases, a lightweight 'nappy splint' may be used. This can be removed for bathing.

Click on 'conservative treatment' for more information about splints.

Some children do not respond to early treatment or some children are not detected until they are older. The approach to treatment for this group is slightly different, and a number of treatment options are available.

Admission to hospital for x-rays and a short period of traction
A small operation in the groin area under a general anaesthetic
A more extensive operation to put the ball and socket in place


After all these procedures it is normal to put the child in a plaster of paris/fibre glass cast which encloses the hips and part of the legs; known as a hip spica.

Treatment in plaster will continue for several weeks or months and may be followed by a period in a splint. After a short initial stay in hospital most children return home with visits to the Outpatient Clinic for check ups. Click on 'surgical treatment' for more information.

How effective will treatment be?

The final outcome will depend on the severity of the condition and the way in which the joint grows, so even the doctor cannot offer guarantees. But for the vast majority of children today effective treatment means that your child will be able to lead a normal active life.

Glossary

When your child is diagnosed with a hip condition you may come across some other terms which are unfamiliar to you. Here are some definitions to help you understand what you are being told at the hospital:

Abducted - to hold apart, away from the centre line

Acetabulum - the cup shaped socket on the hip bone

Bilateral - affecting both sides

Dislocated - when a joint is out of place

Dysplasia - not formed properly

Femur - thigh bone

Idiopathic - cause unknown

Oligohydramnios - lack of fluid surrounding the baby in the womb

Orthopaedics - the branch of medicine that deals with bones and joints. Doctors involved here tend to be surgeons and are addressed as 'Mr' rather than 'Dr'

Prognosis - future outcome that is expected

Tenotomy - the surgical division of a tendon

Unilateral - affecting one side

We gratefully acknowledge the steps Medical Panel
for their assistance in putting this information together.

Hip screening and detection of DDH and CDH

Paediatric hip screening in the UK is beset with problems. This is of concern to both health professionals and parents, as a late diagnosis of a congenital dislocated hip (CDH) or developmental dysplasia of the hip (DDH) can be devastating; requiring surgery, many months in a full body cast, and can often lead to disability later in life. In contrast, early detection and treatment is relatively non-invasive, simple and generally leads to normal hip development. For more information on Campaigns go to the Education and Research section of the website.

Provision and Availability of Equipment for Children in Hip Spicas and Splints

Though several years since it's conception, still one of the most sought after reports for families and professionals concerned with children in 'Hip Spicas' is a report entitled "Provision and Availability of Equipment for Children in Hip Spicas and Splints". It is available to order through the post but you can also download an abridged version of the report from here