Idiopathic Scoliosis: Scoliosis With No Identifiable Cause
The term idiopathic scoliosis refers to structural scoliosis of unknown origin. This type of scoliosis, which can begin at any period during growth, constitutes 80% of all scoliosis cases. It often curves to the right in the thoracic (back) region, and to the left in the lumbar region (waist) and is more commonly seen in girls.
Idiopathic scoliosis is divided into four groups according to the age at which deformity begins.
- Infantile idiopathic scoliosis: It is seen in children under 3 years of age, usually and frequently in boys, with a thoracic curve to the left, and it has no compensatory curvature.
- Juvenile idiopathic scoliosis: They are seen in children between the ages of 4-10, more frequently in boys at younger ages and more frequently in girls at older ages. They are thoracic curvatures to the left/right and they are progressive in nature.
- Adolescent idiopathic scoliosis: Until the completion of 10-year-skeletal development, they are seen more frequently in girls, and are thoracic curvatures to the right.
- Adult idiopathic scoliosis: It is seen in older ages.
The curvature of the patient’s body is noticed by the family or themselves. There may be visible bends in the body, uneven shoulders, lower back and back pain in rare occasions, and respiratory distress in rare occasions. The age of onset of the disease and the sex of the patient are very important. The patient’s body balance and scoliosis measurements and neurological examination are taken as reference.
For a complete and detailed preoperative evaluation, direct scoliosis radiographs are taken in various positions such as standing, lying down and traction. MRI is requested because of the possibility of spinal cord lesions, especially in early patients. Spinal cord and soft tissues are examined in detail with Magnetic Resonance Imaging (MRI). If necessary, detailed and three-dimensional examination of the bones can be performed with Computed Tomography (CT). After all these radiological examinations are completed, matters such as the type of scoliosis, the degree of curvature, the curvature’s location, type, flexibility, and skeletal maturity are decided.
Knowing the natural course of scoliosis detected in the patient is important in the selection of treatment methods that will be performed on the patient. The most important problem with scoliosis is the progression of the deformity and the additional problems caused by the deformity. The goal of scoliosis treatment is to try to stop the curvature until bone maturation is complete and to try to correct the curve after completion. Factors that may affect the risk of progression of idiopathic scoliosis are skeletal maturity, degree of curvature at the time of diagnosis, location and type of curvature, and the patient's gender.
In idiopathic scoliosis, there is a high potential for progression, especially in patients with incomplete bone growth, and it is very difficult to accurately predict the limits of this progression. For girls, the peak height velocity of is the period 6 months prior to menarche. This is also the period during which scoliosis shows the fastest progression. Scoliosis is more progressive in girls than in boys. If the scoliosis angle is above 30°, the probability of progression in girls is 7 times higher. Scoliosis below 30° is unlikely to progress in the adult patient group. Wide curvatures (30°-40°) progress faster than small curvatures (20°-29°). The type of curvature is also an important factor in progress. The thoracic (back) region tends to progress faster than the lumbar region. It is known that beginning the treatment of idiopathic scoliosis at a young age prevents the curvature from reaching the surgical limits in many cases.
Adolescent Idiopathic Scoliosis
The aim of surgical treatment is to obtain a straight and balanced spine by maintaining a good body balance, to stop the progression of curvature, to ensure an acceptable cosmetic appearance, to establish shoulder balance, to ensure the development of the rib cage and good respiratory function. It is known that long-term severe lower back, back pains and serious psychological problems (low rate of marriage) are observed in non-operated individuals. The timing of surgery is as important as the type of surgery and the strategy to be followed for these patients who will undergo surgery for these purposes.
Although the curvatures in some patients are at the surgical limits, the decision of surgical treatment may be delayed by considering factors such as trunk and height growth. Although the degree of scoliosis is below the reported standard values in some cases, surgical treatment may be recommended. In fact, the reason for preferring late surgery in patients is not to affect the patient’s growth potential. However, in the meantime, the excessive progression of the deformity may lead to preferring early surgery due to surgical intervention becoming riskier. As a rule of thumb, surgery is recommended for curvatures with an angle greater than 40° and, after the completion of maturation of the skeletal system, for curvatures greater than 45°. However, the surgical treatment criteria and the timing of the surgery are not strictly defined, and depend on the condition of the patient and their scoliosis, as well as the joint decision of the family and the surgical team.
All spinal curvatures diagnosed before the age of 10 are defined as early-onset scoliosis. There is no single definite guideline for the treatment of these patients. Although congenital scoliosis is also seen in young ages, surgical treatment is explained in its own section, rather than this section. Timely diagnosis, monitoring, and treatment of infantile idiopathic scoliosis and juvenile idiopathic scoliosis patients are very important. 5 years of age is very important for the development of the heart and lungs. Lung tissue may also develop until the age of 8. It is known that early-onset scoliosis may cause long-term cardiac and pulmonary problems. The main purpose of follow-up and treatment is to reduce or stop the progression of the deformity without blocking the thoracic (rib cage) development and spinal elongation. Usually, fusion (bone union) is not performed while performing stabilization in the surgical techniques developed for this purpose. While the deformity is corrected to a certain extent in this way, the main objective is to prevent the progression of scoliosis. However, after the maturation of the skeletal system is achieved, correction of the deformity by conventional fusion surgery will still be performed.