Wrapping our hips out of joint
The practice of wrapping infants to settle has become increasingly more popular in Australia with little regard for the detrimental effect this practice can have on the developing hip. Incorrect wrapping or the use of inappropriate commercial devices that
hold the hips in extension or reduce hip movement can have a severe effect on the growing hip joint and lead to developmental dysplasia of the hip (DDH).
Developmental dysplasia of the hip (DDH) refers to a condition whereby the infant’s hip fails to develop appropriately and may dislocate. Early referral to a specialist paediatric orthopaedic service for management is vital, as late diagnosis requires complex surgery in childhood and can lead to problems in adult life such as osteoarthritis.
In the womb, babies generally lie with their hips in an outward position. This helps the hip joint to develop normally. Instability of the hip is present in around 1 in 100 live births and usually spontaneously resolves in the neonatal period. However, wrapping the legs in an extended position can compromise the normal growth of the hip, causing it to become unstable and dislocate. This risk is increased for infants who have a family history of DDH, are born breech, or have packaging deformities such as plagiocephaly or torticollis. In South Australia at the Women’s and Children’s Hospital, it had been observed that of the babies treated for late diagnosis of DDH (≥ 3 months of age), 79% had been swaddled (Williams, Foster and Cundy 2012).
A systematic review of 11 epidemiologic studies showed that the incidence of DDH is highly correlated with the traditional use of swaddling for newborn infants (van Sleuwan et al 2007). For cultures such as in Japan, Turkey and the Navajo Indian, in which the practice of swaddling is more common, a higher rate of DDH has been noted (Mahan & Kasser 2008). Studies have shown that when this practice is stopped, the incidence of hip dislocation drops significantly. A national campaign to discourage swaddling infants with the hips and knees in extension in Japan was associated with a subsequent reduction in the rate of DDH from 3.5% to 0.2% (Yamamuro & Ishida, 1984). Animal studies have also shown that straight legged swaddling increase the prevalence of developmental dysplasia of the hip especially if the swaddling was early or prolonged (Wang et al 2012).
There are many ways to wrap babies by using muslin wraps or commercially available products that provide ample room for the legs to move. It is vital that parents are aware of the risks associated with wrapping the hips and knees in extension, particularly in the first months of life. Safe wrapping involves the legs being wrapped loosely to allow for hip flexion and abduction . The legs should be able to bend at the hips with the knees apart. This position will assist proper development of the hip joint.