I. Definition of Adolescent Idiopathic Scoliosis (AIS)

Adolescent Idiopathic Scoliosis (AIS) is a spinal deformity characterized by an abnormal lateral curvature of the spine, typically diagnosed during adolescence. The term "idiopathic" denotes that the cause of the condition is unknown, and it manifests without any underlying congenital or neuromuscular abnormalities. AIS is the most common type of scoliosis, accounting for approximately 80% of all scoliosis cases.

II. Prevalence and Age Groups Affected

AIS primarily manifests during the growth spurt that occurs just before puberty and is often detected between the ages of 10 and 18. While it can affect both genders, it is more common in females. The prevalence of AIS varies geographically, with estimates ranging from 0.5% to 3% of the adolescent population. The condition's progression tends to be more aggressive in females, and a family history of scoliosis increases the likelihood of its development.