Etiopathogenesis of idiopathic scoliosis

Abstract

Scoliosis is a three dimensional deformity of the spine characterized by rotation of the vertebrae in the transverse plane and curvatures in the frontal and sagittal plane. The key radiographical tool for diagnosis is Cobb angle, which is the angle created by lines crossing over the upper limit of the first vertebra in the curve and the lower limit of the lowest and final vertebra in the anterior-posterior radiography. Although this cannot entirely describe all spinal abnormalities , it is easy to calculate and to assess and has become the gold standard for scoliotic diagnosis. Deformity is the main clinical sign during the examination, not followed by the presence of pain. The spine may be obviously deviated from the midline ,or this may become apparent only when the patient bends forward (the Adams test). The major curvature may be located at the thoracic, thoracolumbar or lumbar part of the vertebral column and the convexity may point to the left or right side, with compensatory and smaller curvatures above and below. The most common pattern is a thoracic curvature with right convexity with a compensatory left convexity at the lumbar vertebrae. Scoliosis is divided, in terms of etiology, into idiopathic (no known cause or disease), congenital (present at birth due to congenital etiological factors), and secondary(where it is caused by another disease). Idiopathic scoliosis consists, moreover, of three sub-categories, according to the age of diagnosis, as infantile (between 0-3 years old), juvenile (between 4-9 years old) and adolescent (age 10 up to maturity). Adolescent idiopathic scoliosis (AIS) has a prevalence rate between 1-3% and is more common in girls during puberty. The number of girls with AIS is two times higher than the number of boys with this disease and the prevalence is eight times higher among girls than boys when the deformation consists of curvatures greater than 30 degrees. Research into the etiopathogenesis of idiopathic scoliosis (IS) has spread through the years to multiple areas and a great number of suggestions has been made during the last decades concerning hormones, genetic , metabolic and biomechanical factors. Although a lot of theories have been proposed, none is capable to fully describe the pathophysiology of the disease, underlying the complexity and the multifactorial etiology of the condition. The purpose of this review is to summarize the main concepts of etiology Abstract Scoliosis is a three-dimensional deformity of the spine. The key radiographical tool for diagnosis is the Cobb angle and the most common form is a right thoracic convexity with a compensatory left lumbar convexity. Scoliosis is divided, in terms of etiology, into idiopathic, congenital, and secondary. Research into the etiology of idiopathic scoliosis has focused on multiple areas and a great number of suggestions has been made during the last decades concerning hormones, genetic, metabolic and biomechanical factors. Although a lot of theories have been proposed, none is capable to fully describe the pathophysiology of the disease, underlying the complexity and the multifactorial etiology of the condition. The purpose of this review is to summarize the main concepts of etiology and highlight the pathogenetic theories under research in order to reveal possible “targets” for our efforts to understand, diagnose and treat idiopathic scoliosis.