Scoliosis occurs in around 3-5% of the population. A distinction is made between idiopathic and congenital scoliosis, with the idiopathic form being the most common form of scoliosis.
Congenital scoliosis is caused by malformation and/or maldevelopment of individual vertebral bodies.
Idiopathic adolescent scoliosis (IAS) is a change in the normal shape of the spine that occurs in all three levels of the spine - coronal, sagittal and transverse.
Scoliosis is most easily recognized by the curvature to the side (coronal plane). This curvature in the coronal plane is always associated with a rotation of the vertebral bodies. As the ribs are attached to the individual vertebral bodies, this rotation results in the formation of a more or less pronounced rib bulge, which depends on the extent of the rotation, or the formation of a lumbar bulge.
Left: Schematic representation of scoliosis. Right: Healthy spine © Koterka Studio| AdobeStock
When describing scoliosis, however, the sagittal profile (view of the spine from the side) must not be forgotten, as IAS is often accompanied by a marked change in the sagittal profile as well, particularly in the sense of the formation of a flat back.
Women are significantly more frequently affected by scoliosis than men in a ratio of 80:20. Scoliosis usually first becomes apparent at the age of 10-12 years, often after a significant growth spurt.
The most striking features that play a role in recognizing IAS are the lateral curvature and rotation of the vertebral bodies with the development of the above-mentioned deformities in the thoracic and/or lumbar spine.
Today we assume that IAS is caused by a genetic disorder, although the "scoliosis gene" has not yet been discovered. This hypothesis is also supported by the fact that in families in which scoliosis has been diagnosed, IAS often develops in subsequent generations, often skipping a generation.
If there is a suspicion that a curvature of the spine is developing, the following examinations are necessary.
As part of the clinical examination, the doctor looks at the child from behind and palpates the spinous processes of the spine. A curvature of the spine is visible relatively early on, either in the thoracic spine (thoracic spine) or lumbar spine (lumbar spine).
If a rotational misalignment of the vertebral bodies has already occurred at this stage, a more or less pronounced rib or lumbar bulge is present.
In the early diagnosis of scoliosis, this rib bulge formation is of considerable importance, as the scoliosis often becomes more pronounced during an active inclination movement(forward inclination of the trunk), whereby the rib bulge becomes more prominent. The reason for this is that the lateral curvature is partially compensated for during prevention, but not the axial rotation, which then makes the rib bulge clearly visible.
During the clinical examination, it is important to note whether the waist triangle is narrowed or retracted. In the case of scoliosis in the lumbar spine section, the curvature of the spine, usually to the left, results in a bulging of the waist triangle on the left side and a retraction of the waist triangle on the opposite side.
If these clinical changes are recognizable, a radiological diagnosis should be carried out as quickly as possible. Care should be taken to ensure that a full spine radi ograph is always taken during the first X-ray examination, both in the coronal and sagittal plane (viewed from the side).
It is important that the first radiological diagnosis is made in both planes, as the changes in the lateral profile can already provide very good indications of the further development of the IAS.
Once IAS has been confirmed clinically and radiologically, regular check-ups are necessary to detect progression.
Not every mild scoliosis worsens during further growth. At this stage - scoliosis curvature measured radiologically between 15 and 20° - there are 3 possibilities:
- The scoliosis persists in this situation.
- The scoliosis worsens as the curvature increases in all 3 planes.
- In a smaller percentage of scolioses in the above-mentioned range, the curvature even regresses.
If a scoliosis of 15-20° is diagnosed, physiotherapy treatment is initiated as soon as possible and many patients are recommended a corset treatment.
However, in the case of scoliosis with an angle of 30° or more , the muscle strengthening provided by physiotherapy can no longer achieve any improvement. Nevertheless, further targeted exercise is advisable, whereby physiotherapy should also be combined with appropriate respiratory therapy.
Physiotherapy, not even Lehnert-Schroth physiotherapy, is definitely not able to halt the progression of scoliosis. Furthermore, the patient and the attending physician should know that corset therapy is never able to stop the progression of scoliosis.
However, there are a number of reasons why corset treatment is often initiated without any thought:
- To date, there is no evidence that brace treatment can permanently halt the progression of scoliosis. It is considered a very favorable result if the scoliosis does not become more curved, although I have already mentioned the possible development of scoliosis above.
- A major reason against brace treatment is the negative influence of brace treatment on the sagittal (lateral) profile of the spine, which in most cases is already altered in the sense of a lordosis (in most cases thoracic scoliosis) in the sense of a de-kyphosis of the spine (apical, thoracic lordosis).
- The third important point is that corset treatment is not based on a direct corrective intervention on the spine, but is supported by the ribs of the spine. As a result, long-term brace treatment, which can often last 4-5 years if the spine is detected early, leads to considerable changes in the area where the ribs are attached, namely in the costotransverse and costovertebral joints (the ribs are connected to the corresponding vertebral body via 2 joints).
This pressure-related change in the area of the costovertebral joints leads to a significant increase in rigidity. If surgical measures should or must be initiated after many years of brace treatment, these changes are a significant problem during surgical correction.
The increasing ankylosis (stiffening of the vertebral joints) poses a considerable problem in the surgical treatment of scoliosis.
When is surgery necessary?
Depending on the progression (progressive worsening) of the scoliosis, surgical treatment is necessary, with the peak age being between the ages of 12 and 16, depending on the speed of growth. The timing of the operation should be delayed as much as possible in order to minimize the negative influence of the operation on the further longitudinal growth of the spine.
A rough indication for surgery is an angle formation of more than 40° in the coronal plane.
However, the progression of scoliosis is not only expressed in the coronal plane, but also in the sagittal and rotational planes, so that these two planes must always be taken into account when surgery is indicated. For example, a scoliosis with an angle of 30° and a very strong rotation may be an indication for surgery, as it can be predicted with a high degree of certainty that the scoliosis will deteriorate significantly over time.
When considering the indication for surgery, it should also be noted that the progression of scoliosis does not end with the completion of spinal growth (16/17 years). This can be explained quite simply by the fact that, particularly in the lumbar spine, the scoliotic incorrect posture leads to massive incorrect loading of the intervertebral discs (increase in pressure in the disc on the concavity of the scoliosis), which then leads to premature, non-physiological degeneration of the intervertebral discs, which in turn is accompanied by a worsening of the curvature.
This is particularly evident in so-called thoracolumbar or lumbar scolioses, where an increase in scoliosis is predictable with an increase in pain due to the above-mentioned mechanism.
The purpose of an operation to correct the deformity in all three planes is not only to improve the cosmetic appearance, which can also lead to psychological stress in pronounced forms, but also to avoid secondary consequential damage (early degeneration of the scoliosis with resulting considerable pain in adulthood), which then often leads to a larger and more serious operation in adulthood.
Surgical techniques
Various approaches are possible to achieve surgical correction of scoliosis:
- The posterior approach to the spine, which is the most commonly used, but is associated with various disadvantages (longer instrumentation, inadequate correction of rotational misalignment and sagittal malalignment).
- The anterior approach to the spine, which is an anterior, lateral approach. With a suitable indication, this approach allows very good correction in all 3 levels of the spine, combined with generally shorter instrumentation into the lumbar spine. The shortest possible instrumentation and stiffening in the lumbar spine is of great functional importance, as around 70-80% of the overall movement results from the spine.
- In the case of very rigid scolioses or double curves, a double approach (from the back and front laterally) may be necessary in order to achieve an optimal cosmetic and functional result.
In the context of the ventral approach (from the front), the tethering technique, which has been used for around 5 years, should also be mentioned. Here, an attempt is made to correct the scoliosis without fusion (stiffening) via an anterior, lateral approach. The aim is to achieve correction by restraining growth on the convexity of the scoliosis and further growth on the concavity of the scoliosis.
The first medium-term results show partially good corrections. However, it is important to note that this technique has no significant influence on the lateral profile and on the axial rotational deformity; a correction is mainly achieved in the frontal plane.
At the present time, this "tethering technique" cannot yet be conclusively assessed. However, it offers an interesting approach that allows a limited degree of critical optimism.
