In idiopathic infantile scoliosis, boys account for 60% of cases. It is reported that up to 90% of cases can resolve spontaneously, but those that do not can go on to become a seriously debilitating and even life threatening condition.  The first thing a clinician needs to be aware of is that infantile scoliosis can be an extremely serious condition. It is much more progressive than adolescent idiopathic scoliosis with a much higher rate of underlying pathology. In fact in a study by Nachemson et al.[1] looking at the causes of death and mortality in people with untreated scoliosis found that “the mortality was significantly increased in infantile (P < 0.001) and juvenile (P < 0.01) scoliosis but not in adolescent scoliosis”. Hence infantile and early onset scoliosis are conditions that need to be taken very seriously and the appropriate treatment needs to be sought.

In regards to pathological causes, a study by Dobbs et. al.[2] found a “21.7% prevalence of neural axis abnormalities” including Arnold-Chiari malformation, syringomyelia, a low-lying conus, and a brainstem tumour. Of these infantile patients 80% of them required neurosurgical intervention. Across the scientific literature, the studies do differ on the rate of neural axis abnormalities with a reported range from 11% to 50%. However a figure of 13% to 20% seems to be the most widely accepted and is supported by the largest studies.

There is a range of other syndromes and pathologies that can be associated with a scoliosis in an infant. Congenital deformities can occur in isolation or in syndromes, and if a congenital abnormality is detected then these patients must also be evaluated for cardiac and renal abnormalities as some of the syndromes that can cause scoliosis also affect these organs i.e. VATER syndrome,  VACTERL syndrome and Spondylocostal dysostosis to name just a few.

Scoliosis in infants can also be the result of a neuromuscular disorder such as cerebral palsy, spinal cord trauma, muscular dystrophy, spinal muscular atrophy, and spina bifida. Scoliosis secondary to these type of scoliosis are more rapidly progressive than idiopathic types and often require surgical treatment.

Thankfully, most infantile scoliosis patients do not have a pathology or disorder and can be managed with experienced non-surgical treatment. The question for the chiropractic clinician is how we distinguish between the idiopathic and non-idiopathic cases. A complete history is important, including gestational history, birth history particularly in respect to any trauma and history of milestones and family history, especially of syndromes and scoliosis can be helpful. Many neuromuscular conditions will be brought to attention via a proper history.

A good examination is a must. In infants much of the examination will be performed recumbent. Two very important tests are the modified Adams test and abdominal reflexes. The modified Adams test is performed by laying the infant prone on the anterior thighs of a parent who is seated.  Forward flex the infant over the parent’s thighs and look for any rib humping. As demonstrated in the photo below.

A complete neo-nate neurological screening should be performed, however the most important neurological screening test for infantile scoliosis is assessment of abdominal reflexes. While some authors have reported that abdominal reflexes are often absent in infants, the best research suggests that in fact abdominal reflexes should always be present in a healthy infant. This study suggests that the absence of this reflex when tested in infants is either due to spinal cord pathology, neurological syndrome or poor examiner technique! Harlem et. Al.[3] explore this issue at length and found in their study of over 200 infants they were able to elicit the reflex in all cases, however they had to make sure the infant was relaxed, they used a blunt needles, sometimes they had to oil the infant’s skin over the umbilicus and even had to repeat the test at different times if the infant was bloated or stressed.

Many of the orthopaedic tests performed in adult cases have limited utility in infants. However routine screening of hip pathology is extremely important. The two most reliable physical exam tests are Ortolani’s maneuver and Barlow’s test. In particular these tests help to screen for Developmental Dysplasia of the Hip (DDH) which will sometimes present as a lumbar scoliosis in ambulatory children.

If infantile scoliosis is suspected via a clinical examination, radiography is MANDATORY! While many of us are hesitant to order or perform radiographs on infants, if there is a genuine suspicion of an infantile scoliosis then they must be performed. Radiographs are the only way to objectively assess the curve and any potential deformity. Indeed by doing a special measurement called the Rib Vertebral Angle Difference (RVAD), a clear prognosis can be established in most cases. X-rays also help to rule out issues such as congenital abnormalities, trauma, and even cases of physical abuse (look for new and old fractures especially the ribs). Standard radiographs for non-ambulatory children are the AP supine view and lateral recumbent view. In most cases assistance to hold the child in their normal altered posture is required by two assistants wearing a lead gowns.

The RVAD is calculated by subtracting a from b. If the difference is equal to or greater than +/-20 then curve is considered very progressive.

In addition, the Cobb angle is also important as curves greater than 20 degrees of Cobb angle have a higher correlation with an underlying pathological cause than those with a Cobb less than 20 degrees. 

Referral and co-management is an important consideration. If there is any suspicion of congenital, neuromuscular or syndrome-related scoliosis then referral to a physician who specialises in the management of infantile scoliosis is recommended.  In addition, if the Cobb angle is greater than 20 degrees, the RVAD difference is greater than 20 degrees, or if there are no abdominal reflexes then an expert opinion should be sought.

In cases where the scoliosis is considered idiopathic or indeed where a curve is less than 20 degrees and spinal curvature is viewed to be caused by secondary reasons such as mild birth trauma (not CP cases), then observation or low force chiropractic management may be appropriate. If the case is idiopathic but the Cobb is greater than 20 degrees or the RVAD is greater than 20 then it is imperative that custom spinal bracing is considered. There is a limited window for bracing to be effective in infants but within this window braces are highly successful and in most cases can correct the curve.  In cases where there is gross deformity, or a rapidly progressing congenital, neuromuscular or syndrome, serial casting under general anaesthetic would be the step before surgery. If this then fails minimally invasive extendable systems are normally favoured such as the VEPTR (vertical expandable prosthetic titanium rib) or growing rods. However these interventions are a last resort and generally only used in cases where patients have failed non-surgical care.

In summary: Infantile scoliosis can be a serious disease. Although the incidence of it is rare, there is a relatively high association with some type of pathology or underlying syndrome. Hence a thorough work up and examination in these cases is essential. Early treatment and accurate diagnosis leads to better outcomes and if in doubt refer the case to a health care professional who specialises in the management of children with scoliosis for further evaluation.

[1] Pehrsson K1, Larsson S, Oden A, Nachemson A; Long-term follow-up of patients with untreated scoliosis. A study of mortality, causes of death, and symptoms..  Spine (Phila Pa 1976). 1992 Sep;17(9):1091-6.

[2] Dobbs MB1, Lenke LG, Szymanski DA, Morcuende JA, Weinstein SL, Bridwell KH, Sponseller PD; Prevalence of neural axis abnormalities in patients with infantile idiopathic scoliosis. J Bone Joint Surg Am. 2002 Dec;84-A(12):2230-4.
[3] O. K. Harlem, A. Lönnum; A Clinical Study of the Abdominal Skin Reflexes in Newborn Infants
Arch Dis Child. 1957 Apr; 32(162): 127–130.

Written by Dr Jeb McAviney (Chiropractor, Scoliosis Bracing and Rehabilitation Clinician)