What is scoliosis?
Scoliosis is a three-dimensional deformity of the spine that occurs in the coronal (frontal), sagittal (lateral) and axial planes. In 80% of the cases the cause is unknown and therefore it is called idiopathic.
The remaining 20% correspond to the different types of scoliosis: congenital, neuromuscular, neurofibromatosis, early onset and adult scoliosis. Idiopathic scoliosis (IS) is classified according to the age of onset as infantile (newborn – 3 years of age), juvenile (3 years – 9 years) and adolescent (AIS) (10 years – 18 years).
Who is affected?
The prevalence of AIT in the general population is 0.2%-0.5%. The relationship between male and female gender depends on the magnitude of the curve measured in the frontal plane in a standing X-ray.
In general there is a preponderance of girls over boys. The ratio women/men is 2:1 in curves over 10º, 5:1 in curves over 20º, 10:1 in curves over 30º.
What are its causes?
Idiopathic scoliosis is a deformity of unknown origin, however, a relationship with different mechanisms has been found:
- Genetic cause. Approximately 30% of patients have a family history of scoliosis. The probability of developing a curve greater than 10º is 11% in first-degree relatives and 2.4% in second-degree relatives. It is inherited in an X-linked multifactorial polygenic manner.
- Neurological mechanisms. Alteration in the mechanism of balance control (vestibular-visual) and position (proprioceptive dysfunction).
- Biomechanical mechanisms. Growth and muscular alterations and postural control disorders.
- Histological and chemical alterations. Alterations of platelets and calmodulin.
- Connective tissue alterations. Decreased type III collagen fibers6 and decreased glucosamine in the disc.
- Hormonal alterations. There is a different response to growth hormone (GH) as well as decreased nocturnal melatonin levels.
And its symptoms?
The presence of a prominence in the back, difference in shoulder height and asymmetry of the waist triangle in an adolescent should raise suspicion of scoliosis. Pain is NOT a characteristic symptom of IE and should raise suspicion of another cause of the deformity.
Deformity in the axial plane is characterized by rotation of the vertebrae resulting in rib deformity. This manifests in the anterior region as an asymmetry of the breasts and in the posterior region as a hump. The hump is a prominence of the rib cage or lumbar musculature depending on the level of the curve.
How is it treated?
The treatment of scoliosis will depend on the magnitude of the curve.
- Curves less than 25º. They are considered subsidiaries of conservative treatment without the use of a brace, but clinical follow-up and X-rays until the end of growth.
- Curves between 25-45º. In patients in the growth phase with curves greater than 25º and documented progression of the curve, conservative treatment with the use of a brace is indicated.
- Curves above 45º. Patients with curves above 40-45º in growth phase may have surgical indication in order to avoid curve progression. Surgery consists of placing a series of implants in the vertebrae to mechanically correct the initial deformity. These implants can be screws and hooks that are connected to each other by means of metal rods, synthetic bands or cables and allow maintaining the correction of the curve until the bony fusion between the vertebrae is achieved.
Rehabilitation treatment is controversial. There are no studies that demonstrate correction of the curve by rehabilitative treatment. Various techniques and specific programs have been developed that include self-correction exercises, elongation and expansion of the rib cage.
In general, it is recommended to maintain the practice of regular sports activities and to include a stretching program that includes the hamstring muscles.
Treatment with a brace has been shown to prevent curve progression in up to 75% of cases (patients reach skeletal maturity with curves that do not reach 50º). Full-time bracing is recommended (18-20 hrs).
Clinical and radiological follow-up is performed to confirm the validity of the treatment. The brace is usually removed progressively, with a period of nocturnal use before its definitive removal.