Development dysplasia of the hip in children

What is Developmental dysplasia of the hip (DDH)?

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 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.

How common is it?

Around 1 or 2 in every 1000 babies have developmental dysplasia of the hip that needs treatment. It may affect one or both hips but is most common in the left hip and is also more common in girls.

Why does it happen?

Developmental dysplasia of the hip (DDH) can happen to any baby, but some factors make the condition more likely.

The most common risk factors are:

• a baby born breech or who was in the breech position in the last three months of pregnancy
• a close family history of developmental dysplasia of the hip or hip problems that came on in early childhood
• increased risk with twins or multiples births

Sometimes there is no identified risk factor and the cause is unknown. A possible factor that could hinder normal hip development is tight swaddling. Anything that pulls the hips straight or restricts their natural movement should be avoided.

What is the treatment?

If your child is diagnosed with developmental dysplasia of the hip after 6 months of age or if the Pavlik harness has not worked, it is likely that surgery will be recommended. Your consultant will discuss the best and most appropriate treatment options with you.

What is a closed reduction?

Your child will be admitted to hospital and have a general anaesthetic for surgery.

A closed reduction involves gentle manipulation of the thigh bone so that the ball of the bone is placed into the hip socket without making any cuts.

Sometimes the tendon in the groin can be tight and a small cut may need to be made to the tendon to help with reducing the hip. This is called an adductor tenotomy. Once the ball of the bone is in place in a stable position, a hip spica is applied. The time in the hip spica cast can vary. This is usually 12 weeks, with a change of hip spica in theatre at 6 weeks.

You may be able to go home the same day as surgery or you may stay overnight while you become familiar with the hip spica and cares.

What is an open reduction?

If the closed reduction is not successful or your child is diagnosed over the age of 1 years old then open reduction would be recommended.

In an open reduction procedure, surgery is done to bring the the ball thigh bone into the hip socket.

Surgery is done through a cut in the groin. The surgeon will carefully release tight tendons and ligaments to make sure the socket is clear.

Sometimes we may also need to correct bone deformities and restore normal anatomy by carefully dividing the bone which is called an ‘osteotomy’.

Once the hip is in joint in a stable position, a hip spica is applied. Your child will be in a hip spica cast for up to 12 weeks. The spica will be changed in theatre at 6 weeks at which stage the hip will be reassessed and a new spica applied.

What is a hip spica?

A hip spica is a cast used to keep the hip in position after surgery. It is made of plaster of paris and fibreglass. It goes from the torso down one or both of your child’s legs. It will have a gap left in the middle for toileting.

Sometimes there may be a bar placed in the middle of the cast between the legs. The type of hip spica will be decided by the consultant depending on the type of surgery performed and the treatment needed.

You will be taught how to care for your child while they are in the hip spica when you are on the ward. You will only be discharged when you feel comfortable caring for your child in the spica.

Equipment

Car seat

If your child uses a car seat it is likely that they will no longer fit in their usual one. A couple of companies offer hire or purchase options for modified car seats to use for hip spicas.

• Maxi cosi hip service hire car seat is £10 a month
• In car safety centre car seat is £220 or you can hire one from £175

Alternatively, you will be provided with a car seat exemption form to get you home from hospital and which can be used to get to and from follow up appointments whilst in spica. It may only be used for these reasons.

Pushchair

If your child uses a pushchair day to day it may be that they can still use their usual pushchair. Please bring it with you into hospital on admission for the occupational therapists to take a look at it. If not they will discuss ways they can help to provide support for your child when in the pushchair. For example, rolled blankets or pillows.

High chair

Your child most likely will not fit in their normal highchair due to the width of the spica. Instead, you could use a travel booster seat that attaches to a dining chair, sitting on the sofa with pillows or eating on a beanbag.

Moving and handling

You will be shown how to safely pick up and move your child for everyday activities whilst in hospital. The most important thing is to always support the cast so the weight is not pulling on the hips.

Clothing

You may need to size up clothes to fit them over the spica. Your child will most likely not be able to fit into trousers whilst in spica. Suitable clothing include vests (in the next size up), t-shirts, jumpers, dresses.

Activities

There are lots of activities you can do with your child when they are in the hip spica. For example, colouring, reading, play doh, building blocks, jigsaws, baking, watching films, walks in the pram

Sleep

Your child will need to sleep on their back whilst in the hip spica with pillows for support. Nursing and the occupational therapy staff will show you how best to position the pillows whilst on the ward. You will need to alter your child’s position regularly every 4 hours to ensure your child does not get pressure areas.

Hygiene and bathing

You should not get the hip spica wet. If you do, please contact the plaster room in hours or the ward for advice. You will need to try to dry it out as best you can.

We suggest sponge baths whilst in spica. Nursing staff on the ward will go through washing with you whilst on the ward.

A gap is left in the middle of the spica to allow for toileting. If your child is in nappies a 2 nappy technique is used. A smaller one placed on the inside of the spica and a larger nappy on the outside to hold the small one in place. This will be demonstrated to you in hospital and nursing staff will make sure you are comfortable with changes before discharge.

If your child is no longer in nappies you may need some equipment, such as a bed pan or toilet chair, organising for home to allow your child to use the toilet whilst in spica.

Contact the ward for advice if your child’s nappy leaks and you are concerned.