Mechanism of right thoracic adolescent idiopathic scoliosis at risk for progression; a unifying pathway of development by normal growth and imbalance.

Adolescent idiopathic scoliosis is regarded as a multifactorial disease and none of the many suggested causal etiologies have yet prevailed. I will suggest that adolescent idiopathic scoliosis has one common denominator, namely that initial curve development is mediated through one common normal physiological pathway of thoracic rotational instability. This is a consequence of gender specific natural growth of the passive structural components of thoracic spinal tissues for the adolescent female. This causes an unbalanced mechanical situation, which progresses if the paravertebral muscles cannot maintain spinal alignment. The alteration in the coronal plane with the lateral curve deformity is an uncoupling effect due to a culmination of a secondary, temporary sagittal plane thoracic flattening and of a primary, temporary transverse plane rotational instability for the adolescent female. Treatment of adolescent idiopathic scoliosis should address this physiological pathway and the overall treatment strategy is early intervention with strengthening of thoracic rotational stability for small curve adolescent idiopathic scoliosis.