Introduction and Prevalence
Adolescent Idiopathic scoliosis (AIS) is the most common spine deformity and is defined as a curve of over 10 degrees on x-ray. It affects up to 4% of adolescents in the early stages of puberty and a total prevalence range of 0.4-2.5% in Asia. It can be up to 11 times more common in girls. This comparison with boys increase for more severe curves: 2.7 times for ≥10 o, 4.5 times for ≥20o, 8.1 times for ≥30 o, and 8.4 times for ≥40o. AIS has heritability. Up to 11% of first-degree relatives also have AIS. The condition occurs in otherwise healthy individuals and currently has no recognizable cause. Patients with AIS tend to be taller than those without AIS and have longer arm span and leg length. AIS also correlates with abnormal body composition including a lower body weight and lower body mass index than those without the condition.