When you first hear the term ‘hip dysplasia,’ it’s likely you’ll assume that this is an adults only condition, but one in 100 children are diagnosed with hip dysplasia each day in Australia.
Also known as Developmental Dysplasia of the Hip (DDH), the condition involves an abnormality where “the top of the thighbone is not stable within the socket. The ligaments of the hip joint that hold it together may also be loose,” Sydney Paediatrician Dr Reshma Nikam said.
“This can cause instability of the hip joint, making it prone to dislocation.”
What to look out for
Difficulty parting the legs for nappy changes, being unable to move the leg normally, different leg lengths, and uneven thigh creases are just some of the red flags.
Tight swaddling can also increase risk. Dr Nikam says it’s important to emphasise to parents that the swaddle should be comfortable enough for the child to be able to move their hips and knees.
“Breech presentation, being female, twin pregnancies, low levels of amniotic fluid, and a birth weight over 4kg are factors that can increase risk,” Dr Nikam said.
“And an infant is five times more likely to develop hip dysplasia if mum or dad had it when they were kids.”
An infant will also be at higher risk if a sibling had DDH. “We watch these babies closely. Even if their physical examination is normal, they’ll likely undergo a hip ultrasound at six weeks of age.”
According to Healthy Hips Australia, ‘having no risk factors is the biggest risk for late diagnosed hip dysplasia’. While mandatory hip checks occur at one-to-four weeks, six-to-eight weeks, and six-to-nine months, the developmental nature of hip dysplasia means onset can occur up until 12 months of age. Lack of education surrounding DDH means parents may not pick up on the signs in their child at a later age – such as leaning to one side when standing.
Early versus late diagnosis
“If DDH is picked up in the first three to six months, babies respond well to treatment in a soft positioning device (a Pavlik Harness), or a brace,” Dr Nikam said. This is worn for six to ten weeks, until the hip is stable and the ultrasound exams are normal.
Complications are unlikely for these treatments, but if the splinting doesn’t work, a Closed Reduction procedure is performed in theatre under anaesthetic, with the hip joint being moved into the correct position.
“Open surgery may be needed for children over six months, or children whose hips don’t improve with the harness,” Dr Nikam said. In these cases, and sometimes after the Closed Reduction procedure, a plaster cast may be required for a few months.
“Most children’s hips grow normally post-treatment,” Dr Nikam said. She added that there is more than a 90 per cent success rate when the harness is applied to a child under three months of age, “which is why early detection is so important.”
Parents don’t generally talk about their babies’ hips, and the Healthy Hips Week campaign is here to change this. Raising awareness of DDH should help to increase early diagnoses.
“If DDH is left untreated, it can lead to osteoarthritis by early childhood,” Dr Nikam said. “In their first year of life, it is crucial for your child to have regular hip checks by your GP or healthcare worker.”