New Study on Scoliosis from the Growing Spine Study Group

Ten years ago, the Growing Spine Study Group (GSSG) was started in an effort to improve treatment for early-onset scoliosis. Since that time, 22 Spine Centers in seven countries have joined forces to collect data on childhood and adolescent scoliosis. The group is made up of 36 specialized surgeons trained in the treatment of complex spinal deformities among the younger pediatric population (birth to age five).

The GSSG engages in comprehensive, multicenter, prospective research studies. They are committed to an international effort to perform and publish results from the highest quality research studies. Their current focus is on new techniques for spinal deformity surgery.

In this study, they compare the X-ray results of operative idiopathic early-onset scoliosis (IEOS) and adolescent idiopathic scoliosis (AIS). Idiopathic means the cause of the spinal curve is unknown. This type of scoliosis can develop at any age and is therefore named according when it occurs.

For example, spinal curvatures that develop between the ages of birth and three years is referred to as infantile idiopathic scoliosis or IIS. Juvenile idiopathic scoliosis or JIS is first seen in children between the ages of four and nine. And scoliosis that develops between the ages of 10 and 18 is referred to as adolescent idiopathic scoliosis (AIS). The added term “early-onset” refers to children five years old and younger.

Using the GSSG database of collected information, the authors reviewed the X-rays before and after spinal surgery for children diagnosed with idiopathic early-onset scoliosis (IEOS) and compared the results against a second (older) group. They used the records from another (separate) database (the Harms Study Group) for the second group of patients. The Harms Study Group collects data on children with adolescent idiopathic scoliosis (AIS).

In this way, they could identify differences in the characteristics of the spinal curvatures between these two age groups (birth to age five from the Growing Spine Study Group and 10 years to 18 years from the Harms Study Group). Various spinal angles, lines, curve directions and curve locations (thoracic spine, lumbar spine, thoracolumbar spine), and severity (magnitude) of spinal curves were measured and compared.

Here is a brief summary of the observations made between these two groups:

  • Children with idiopathic early-onset scoliosis (IEOS) had larger spinal curves and larger kyphosis (forward-bending curve).
  • Children in the younger age group were more likely to have one C-shaped curve with the center of the curve located near the place where the thoracic spine meets the lumbar spine (referred to as the thoracolumbar junction).
  • In general, children in the younger group had lower curves (most stable vertebra was in the lumbar spine).
  • Children in the older age group had double curves (S-shaped rather than C-shaped). This is typical as the spine compensates over time for an initial C-shaped spinal curve that eventually becomes an S-shaped (double) curve. The S-shaped curve makes it possible for the head to stay centered over the sacrum/pelvis.

    When the main curve was in children with idiopathic early-onset scoliosis (IEOS), it was to the left in two-thirds of the cases. This compared with 95 per cent of the older (adolescent) children who had a right-sided curve.

    What are the implications of these findings? First, the authors suggest that the lower curves in younger children may require a more distal (lower down) spinal fusion. There are some distinct disadvantages or drawbacks (as the authors refer to them) in doing spinal fusion surgery in the lower lumbar spine. For example, this type of fusion limits spinal flexibility and movement while concentrating stress on one area of the spine.

    Second, with the larger degree of kyphosis in the idiopathic early-onset group, there is a greater chance for pull-out anchors used in the fusion surgery to pull out. This can create a less-than-stable result. The authors suggest the use of carefully placed proximal anchors in such cases.

    Third, the larger curves in the younger children may suggest a tendency to delay surgery in younger groups. But the question is: what’s best for the child in the long-term? Does postponing surgery except in the most severe spinal deformities create more problems later? These are questions that must be addressed in future studies.

    Surgeons treating children with idiopathic scoliosis (whether early-onset or adolescent) may want to follow the work of these two research groups. Treatment approaches and surgical techniques with the best outcomes will be the focus of these multicenter research studies. Membership and participation in these study groups is available for those interested and qualifying individuals and centers.