Community-based baby hip screening reduces late diagnosis

Nurse-led, community-based ultrasound screening for hip dysplasia achieved almost universal reach and identified children earlier than current practices. A University of Tokyo study found that 8.7% of infants had suspected developmental dysplasia of the hip (DDH), including children with no clinical signs or known risk factors.

Hip dysplasia is the most common cause of hip arthritis for people under 50, according to the International Hip Dysplasia Institute. It occurs when a hip socket is too shallow to support the ball of the thigh bone. In young children, this can cause problems ranging from a mildly wiggly hip to complete dislocation. In adults, it can affect how people walk, lead to early-onset arthritis, and cause pain and mobility issues.

Late diagnosis of DDH remains a public health issue worldwide, leading to problems for adults later in life. More comprehensive ultrasound screening of infants during community-based public health services could help catch these missed cases without requiring hospital resources to conduct the initial screening, researchers said.

The methods used to screen newborns for DDH vary around the world. Most countries, including North America, South Korea, Taiwan and Japan, have a selective screening programme based first on a physical exam or family history. Only a small number of countries, including Austria, Switzerland and Mongolia, provide ultrasound screening for all newborns, which is more accurate.

Associate Professor Kyoko Yoshioka-Maeda from the Graduate School of Medicine at the University of Tokyo wanted to explore ways to catch these missed cases earlier. It was also vital to limit the burden on Japan’s medical system which has a declining number of paediatric orthopaedic surgeons.

‘I wanted to find out if these [ultrasound] devices could be successfully used in a community setting to screen infants for DDH as part of the maternal child and health programme,’ Yoshioka-Maeda explained. ‘Based on our nationwide survey, approximately 2% of municipalities use ultrasound screening because of workforce constraints. There is also a disparity between the availability of paediatric orthopaedic surgeons and hospitals in rural areas compared to urban areas.’

In Japan, about a month or two after a mother has given birth, she is visited by a public health nurse or midwife to check her recovery and the baby’s development. Public health nurses can offer guidance and community-based preventative care but differ from midwives and registered nurses in hospitals, and do not commonly use ultrasound.

Public health nurses and midwives from two rural municipalities in the island prefecture of Okinawa in southern Japan, and one in central Japan’s Aichi Prefecture participated in the study. Participants completed an e-learning module and hands-on seminar for the portable ultrasound device and the Graf method (used to diagnose DDH).

Ultrasound images were remotely reviewed by paediatric orthopaedic surgeons or an experienced senior surgeon. In total, 349 infants were screened out of a target 365, giving an overall coverage of 95.6%. Of these community-based examinations, 85.8% of the images were successfully classified by the surgeons.

Based on the ultrasound findings and other risk factors, 42 infants were referred, and of these, 41 attended hospital visits. Overall, 23 infants (54.8%) required follow-up and 2 (4.8%) treatment. However, only 6 of the 42 children (14.3%) would have previously met the criteria for a referral without ultrasound screening, demonstrating its effectiveness to support early detection of DDH.

‘We received strong support from caregivers, municipal administrators, hospitals, public health centres and paediatric orthopaedic surgeons, which was key for the success of this study,’ said Yoshioka-Maeda. ‘In order to roll this out across Japan, the first hurdle is the budget to purchase the equipment and train and support the staff. The other bottleneck is image interpretation, as there is a very limited number of paediatric orthopaedic surgeons in Japan. Developing an AI-based system could help us with that.’