What are the signs of hip dysplasia in babies?

What is developmental dysplasia of the hip?

Developmental dysplasia of the hip (DDH) is a condition in which the hip joint does not form normally. The socket may be shallow, allowing the ball at the top of the thigh bone to be loose, partly out of place or fully dislocated.

An American Academy of Pediatrics clinical report notes that clinical hip instability occurs in 1 to 2 per cent of full-term infants, and up to 15 per cent have hip instability or immaturity detectable on imaging 1. Many mild forms resolve without treatment 1.

Why is early detection important?

DDH is usually painless and clinically silent during the first year of life. It can be treated more effectively if detected early, and untreated DDH can lead to walking problems and early hip arthritis. Hip dysplasia is the most common cause of hip arthritis in women under 40 1.

The main goal of screening is to detect a dislocated hip by 6 to 12 months of age in an otherwise healthy child 1.

What signs can parents notice?

Possible signs include uneven skin folds on the thighs or buttocks, one leg appearing shorter than the other, one knee sitting lower than the other when the baby lies on their back with knees bent, or reduced ability to spread one leg outwards during nappy changes.

In walking children, signs may include a limp, walking on the toes of one foot, or a waddling walk if both hips are affected. Uneven skin creases can also occur in healthy babies, so an examination is needed.

Which babies are at higher risk?

Risk factors include breech position in late pregnancy, a family history of DDH, being a girl, first pregnancies and conditions that limit space in the womb. Tight swaddling with the legs held straight and together can also increase risk.

Babies with risk factors are often offered a hip ultrasound in the first weeks of life, even if the examination is normal.

How are babies checked?

Doctors and nurses examine the hips at routine newborn and infant checks using gentle manoeuvres to feel for instability, and they look for limited hip movement as babies grow. Ultrasound is used in young babies because their hip bones are mostly cartilage, while X-rays are more useful after a few months of age.

Because examination techniques and screening programmes vary between countries, parents should raise any concerns at routine checks.

How is hip dysplasia treated?

In young babies, a soft harness, such as the Pavlik harness, holds the hips in a position that encourages normal development. Treatment often lasts several weeks to months with regular ultrasound checks.

If a harness is not successful or DDH is diagnosed later, treatment may involve a procedure to put the hip into place under anaesthetic followed by a cast, or surgery. Physiotherapy may support recovery of movement and walking after treatment.

How can a harness be managed day to day?

When a baby wears a harness for hip dysplasia, parents are shown how to check the straps, dress the baby and change nappies without removing the harness unless instructed. Clothes that fit over the harness, such as loose vests and sleepsuits, are helpful.

Regular checks of the skin in skin folds prevent irritation. Feeding, cuddling and play can continue normally. Families should contact the clinic if the harness seems loose or tight, the skin is sore, or the baby does not move the legs normally.

How can parents support healthy hip development?

Use hip-healthy swaddling that allows the legs to bend up and out at the hips. Choose baby carriers and car seats that support the thighs with the knees spread apart.

Attend routine checks and seek advice promptly if you notice uneven legs, reduced movement or a limp.

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