Infantile idiopathic scoliosis, or IIS – defined as scoliosis occurring in a child under three years of age – has historically been a very rare phenomenon in North America, but authorities in the field of scoliosis have begun to notice that the incidence of this condition has been steadily increasing over the last decade.1 Many researchers have begun to investigate the relationship between IIS, cranial malformations and the supine sleeping position.
In 1993, Canada and many other countries around the world began recommending that infants be placed to sleep on their backs, and this was later reinforced with the “Back to Sleep” campaign. The incidence of Sudden Infant Death Syndrome (SIDS) in Canada subsequently declined by 50 per cent between 1999 and 2004.2 This reduction in SIDS is commendable, and no one is advocating a return to the prone sleeping position.
However, one unintended consequence of the new sleeping recommendations has been a recognized increase in the incidence of malformations of the cranial bones (plagiocephaly) in particular asymmetries of the occiput.3 One centre noticed a six-fold increase in the cases of plagiocephaly presenting to their facility in the two years immediately following the adoption of the new sleeping guidelines.4 This centre noted that patients with plagiocephaly were more likely to be males, and to have been delivered with the aid of forceps.
In 1985, McMaster reported on the decreasing incidence of IIS in Edinburgh, Scotland, and postulated a relationship between cases of IIS and the sleeping position.5 Similar to plagiocephaly, IIS favours the male gender and birth trauma and the use of forceps is associated with a high prevalence of scoliosis.6 However, contrary to the plagiocephaly situation, McMaster noted the incidence of IIS was decreasing when recommendations for the prone sleeping position were routinely followed. A similar finding was noted in Germany in 1981.7 In fact, research as far back as 1966 has stated that one of the benefits of the prone sleeping position was prevention of scoliosis.8
In most cases of plagiocephaly, the condition is self-resolving. One study found plagiocephaly to be present in 20 per cent of eight-month-old infants, but that by the age of two years, this number had decreased to three per cent.9 This is comparable to the natural history of IIS; most studies of IIS conclude that the majority of cases resolve spontaneously, without requiring treatment of any kind. However, it has been known since 1959 that those cases which do not resolve on their own generally continue to worsen throughout life, and tend to progress to the point of causing death or disability in early adulthood.10
The relationship between IIS and plagiocephaly has not been extensively researched, but the few studies on the topic show an incredible degree of correlation. In almost 100 per cent of cases, not only do infants with scoliosis demonstrate malformation of the occipital bones, but the side of malformation also correlates with the convexity of the scoliotic curve.6,11
How chiropractors can help
The undeniable benefits of the supine sleeping position point to the fact that parents should continue to place their children to sleep on their backs.
At the same time, it is important to recognize that plagiocephaly, and hence IIS, can easily be prevented through patient education and chiropractic cranial adjusting techniques. Chiropractors should encourage supervised “tummy time” for infants; supervised awake time in the prone position is not a risk factor for SIDS, and not only does this help to encourage proper development of the cervical and lumbar lordoses, but it also can help promote normal development of motor skills.12
Unfortunately (and possibly due to overzealousness on the part of the parents after the implementation of the new guidelines), 26 per cent of parents never allow their infants to play on their tummies.13
According to Hawes, with the adoption of the new supine sleeping guidelines, we should expect an eighty-two-fold increase in cases of IIS in North America; from 50 cases per 100,000 citizens, to more than 4,000.14
Even if 90 per cent of these cases resolve without treatment, this would result in 400 individuals each year that would go on to develop severe, disabling scoliosis later in life.
By promoting active awareness of what parents can do to help prevent plagiocephaly and IIS, chiropractors have the potential to drastically reduce the burden borne by individuals, families and society due to idiopathic infantile scoliosis.
1) That which is left unspoken: Infantile scoliosis on the rise, www.mariatalksback.blogspot.com, posted July 17, 2011, containing anecdotal reports by Joseph O’Brien, President of the National Scoliosis Foundation.
2) Public Health Agency of Canada. (2008). Canadian Perinatal Health Report. 2008 Edition. Ottawa, Canada.
3) Task Force on Sudden Infant Death Syndrome: The Changing Concept of Sudden Infant Death Syndrome: Diagnostic Coding Shifts, Controversies Regarding the Sleeping Environment, and New Variables to Consider in Reducing Risk. Pediatrics Vol. 116 No. 5 November 2005, pp. 1245-1255 (doi:10.1542/peds.2005-1499).
4) Kane et al: Observations on a Recent Increase of Plagiocephaly without synostosis. Pediatrics Vol. 97 No. 6 June 1, 1996 pp. 877–885.
5) McMaster M: Infantile idiopathic scoliosis: can it be prevented? J Bone Joint Surg 1985;65B:612-617.
6) Ruggieri et al: Spinal cord insults in the prenatal, perinatal, and neonatal periods. Dev Med Child Neurol. 1999 May;41(5):311-7.
7) Mau H: The changing concept of infantile scoliosis. Intern Orthop 1981;5:131-137.
8) McKee et al: Preventing sudden infant deaths – the slow diffusion of an idea. Health Policy 1966;37:117-135.
9) Hutchison BL, Hutchison LAD, Thompson JMD, Mitchell EA. Plagiocephaly and brachycephaly in the first two years of life: a prospective cohort study. Pediatrics. 2004;114 :970-980.
10) James JI, Lloyd-Roberts GC, Pilcher MF: Infantile structural scoliosis, 1959. J Bone Joint Surg Br 41-B:719–735.
11) Wynne-Davies R: Infantile IS: Causative factors, particularly in the first 6 months of life. J Bone Joint Surg 1975;57B:138-141.
12) Hunt CE, Puczynski MS: Does supine sleeping cause asymmetric heads? Pediatrics 1996;98:127.
13) Mildred J et al: Play position is influenced by knowledge of SIDS sleep position recommendations. J Pediatr Child Health 1995;31:499-502.
14) Hawes M: Scoliosis and the Human Spine, 2010, National Scoliosis Foundation.