Scoliosis is defined as a lateral curvature of the spine with torsion of the spine and chest as well as a disturbance of the sagittal profile [²].

Idiopathic scoliosis is the most common of all forms of lateral deviation of the spine. By definition, it is a lateral curvature of the spine in an otherwise healthy child, for which a currently recognizable cause has not been found. Less common but better defined etiologies of the disorder include scoliosis of neuromuscular origin, congenital scoliosis, scoliosis in neurofibromatosis, and mesenchymal disorders like Marfan's syndrome [³].

The prevalence of adolescent idiopathic scoliosis (AIS), when defined as a curvature greater than 10? according to Cobb, is 2?3%. The prevalence of curvatures greater than 20? is between 0.3 and 0.5%, while curvatures greater than 40? Cobb are found in less than 0.1% of the population. All etiologies of scoliosis other than AIS are encountered more rarely [⁴].

The anatomical level of the deformity has received attention from clinicians as a basis for scoliosis classification. The level of the apex vertebra (i.e., thoracic, thoracolumbar, lumbar or double major) forms a simple basis for description. In 1983, King and colleagues [⁵] classified different curvature patterns by the extent of spinal fusion required; however, recent reports have suggested that these classifications lack reliability. Recently, a new description has been developed by Lenke and colleagues [⁶]. This approach calls for clinical assessment of scoliosis and kyphosis with respect to sagittal profile and curvature components. Systems designed for conservative management include the classifications by Lehnert-Schroth [⁷] (functional three-curve and functional four-curve scoliosis) and by Rigo [⁸] (brace construction and application).

The primary aim of scoliosis management is to stop curvature progression [⁹]. Improvement of pulmonary function (vital capacity) and treatment of pain are also of major importance. The first of three modes of conservative scoliosis management is based on physical therapy, including M?thode Lyonaise [¹⁰], Side-Shift [¹¹], Dobosiewicz [¹²], Schroth and others [⁷]. Although discussed from contrasting viewpoints in the international literature, there is some evidence for the effectiveness of scoliosis treatment by physical therapy alone [¹³].

It has to be emphasized that (1) physical therapy for scoliosis is not just general exercises but rather one of the cited methods designed to address the particular nuances of spinal deformity, and (2) application of such methods requires therapists and clinicians specifically trained and certified in those scoliosis specific conservative intervention methods.

The second mode of conservative management is scoliosis intensive rehabilitation (SIR), which appears to be effective with respect to many signs and symptoms of scoliosis and with respect to impeding curvature progression [¹⁴]. The third mode of conservative management is brace treatment, which has been found to be effective in preventing curvature progression and thus in altering the natural history of IS [¹⁵,¹⁶]. It appears that brace treatment may reduce the prevalence of surgery [¹⁷], restore the sagittal profile [¹⁸] and influence vertebral rotation [¹⁹]. There are also indications that the end result of brace treatment can be predicted [²⁰].

Guidelines for conservative intervention are based on current information regarding the risk for significant curvature progression in a given period of time. Each case has its own natural history and must be considered on an individual basis, in the context of a thorough clinical evaluation and patient history [²¹]. Estimation of risk for progression is based on small (n < 1000) epidemiological surveys in which children were diagnosed with scoliosis, and radiographed periodically to quantify changes in curvature magnitude over time [^22-44]. Such surveys support the premise that, among populations of children with a diagnosis of idiopathic scoliosis, risk for progression is highly correlated with potential for growth over the period of observation. In boys, prognosis for progression is more favorable, with relatively fewer individuals having curves that progress to >40 degrees. For SOSORT guidelines, prognostic risk estimation is based on the calculation of Lonstein and Carlson [³³]. This calculation is based on curvature progression observed among 727 patients (575 female, 152 male) diagnosed between 1974?1979 in state of Minnesota (United States) school screening programs, and followed until they reached skeletal maturity. (See Figure 1).

^*These authors contributed by reviewing, text editing and adding certain textfiles and references