The Scoliosis Research Society has prepared this booklet to provide patients and /or their parents with a better understanding of a particular type of spine deformity-congenital, its diagnosis and treatment. This information is intended as a supplement to the information your physician will provide. The behavior of congenital spinal deformities may be very different from one individual to another though a number of general statements can be made. However, your orthopaedic surgeon will be the most important source of information for you or your child’s particular case.
It is beyond the scope of this booklet to discuss in detail the technical aspects of all the various surgical procedures that may be needed. But, general concepts about the surgical treatment are discussed. Additionally, it must be stressed that congenital spinal deformities are much different than the more common idiopathic type of deformity, requiring different evaluation and treatment.
These are spinal deformities-scoliosis (side-to-side) or kyphosis (excessive round-back)-that are caused by abnormally formed or joined vertebrae, which an affected person is born with. The type of deformity that is seen depends on which direction and where the abnormal vertebrae are positioned within the spinal column. The normal spine should be straight when viewed from behind.
When viewed from the side, there should be a gentle roundback (kyphosis) in the thoracic (chest part) spine and lordosis (swayback) in the lumbar (lower part) spine. Scoliosis or increased kyphosis or lordosis are abnormalities and in congenital cases are caused by asymmetric growth of the abnormal vertebrae.
As mentioned above, the key factor causing the spine to curve is the asymmetric growth of the abnormally formed vertebrae. The abnormalities can be classified as: Type I-Failures of Formation (hemivertebrae or incompletely formed vertebrae) and Type II-Failures of Segmentation (vertebrae that are abnormally joined together). There also can be combination of the two. A hemivertebra causes one side of the spine to grow more than the other. Vertebrae that are joined together on one side (unsegmented bar) result in tethering of the growth on that side, again causing the spine to curve.
It is important to note that although the abnormal vertebrae are present at birth, there may not be much of an abnormal curvature at first. This occurs with growth. But even with growth, many of these affected spines may curve very little or not at all. In fact in spines with multiple abnormal vertebrae, the main effect may be significant stunting of trunk growth rather that increasing curvature. There may be very little increase in the curvature until the adolescent growth spurt.
Congenital spinal deformities are generally not considered to be hereditary. However, congenital spinal abnormalities may be associated with other conditions that are.
Therefore, ordinarily, parents of a child with an isolated congenital spinal deformity are not at increased risk for having another child with it. Currently, there is no way to prevent congenital spinal deformity and it is not entirely clear why these abnormalities occur.
Because of the events that occur during the development of the embryo and fetus a number of associated abnormalities can be seen with congenital spinal deformity.
The most common are:
These abnormalities may or may not be functionally significant. Additionally, congenital spinal deformities may be associated with various syndromes (e.g. VACTERL, Goldenhar, Fetal Alcohol) to name a few.
Proper diagnosis of the abnormality should be made as soon as it is recognized. This may involve special X-rays, MRI, ultrasound or other tests. The results of these studies help identify associated problems and provide information about how the spine deformity may behave in the future. Usually a period of what has been called “controlled observation” should occur also to see how the abnormality is behaving. This is done with periodic physical exams and X-rays. If steady increase in the curvature or other functional problems arise, the appropriate surgical procedure(s) should be undertaken.
One of the big differences between congenital and idiopathic deformities is that braces are not effective in congenital deformities. The only effective treatment is to eliminate or modify the asymmetric growth of the abnormal vertebrae most commonly accomplished by spinal fusion. The surgery may have to be done when a child is quite young in order to control a progressive deformity. Parents are understandably concerned that early fusion, which arrests growth of the spine within the fused segment, may lead to stunting of trunk growth. While this is true to an extent, trying to regain trunk height by correcting a very severe curvature after completion of growth is not possible and may be dangerous. Even if early surgery is done, additional procedures may be necessary if the original surgery does not completely control the curve. In actively growing children both anterior (in the front) and posterior (in the back) fusion may be necessary to control the deformity. These techniques can be applied to both scoliosis and kyphosis. Achieving a spinal fusion requires either autograft (a person’s own) or allograft (someone else’s) bone, a bone substitute or a combination of 2 or more of these sources.
Associated problems (e.g. spinal cord abnormalities) may require specific treatment either before, at the same time, or even after the surgical treatment for the spinal deformity. Sometimes, the spinal deformity itself may cause damage to the spinal cord (e.g. congenital kyphosis due to failure of formation) rather than an intrinsic spinal cord abnormality.
Controlled observation – This is accomplished by periodic physical exams and X-rays and is continued without specific treatment as long as no increase in the curve occurs and is continued until skeletal maturity. (It is also done after surgical treatment).
Surgical treatment – Currently all surgical procedures for the treatment of congenital spinal deformity involve fusion of at least 2 vertebrae. These operations may involve fusing the curve without correction (in situ fusion) with or without internal fixation (implanted rods, hooks, etc), correction of the curve with internal fixation plus fusion, removal of a hemivertebra with internal fixation, or fusion of the convex side of the curve only. As mentioned above, growing children often require anterior and posterior fusion to adequately control the curve. It is absolutely essential that the fusion heals, otherwise the procedure will fail and the curve will not be controlled. Newer procedures that do not involve a fusion are being developed but are considered experimental at this time. There are many factors that must be considered in choosing the best procedure for you or your child. The choices available should be discussed with your orthopaedic surgeon.
Post-operative casts or braces – Usually in children either a brace or cast will be used for a period of time after the surgery to help immobilize the spine so that the fusion heals properly. Braces can also help align and balance the adjacent and normal vertebrae which have been drawn into the curve. In older children and adults, rigid internal fixation may eliminate the need for a cast or brace.
Congenital spinal deformities are caused by the asymmetric growth of vertebral abnormalities that a person is born with. While some affected persons never develop a significant curvature, many do and the curvature may become very severe if not recognized and treated appropriately. A number of potentially important associated conditions can exist along with the congenital spinal deformity. Usually a period of observation is needed to assess the behavior of the deformity. If the deformity worsens, the only effective treatment is surgical. A number of operations can be done but at this time all involve fusing a segment of the spine. The surgery is performed when it has been determined that the curvature needs to be controlled, sometimes when a child is quite young. Continued observation until at least the end of growth is necessary for all patients with congenital spinal deformities.