Criteria for the treatment of idiopathic scoliosis between 40 degrees and 50 degrees. Operative versus conservative therapy

The treatment of idiopathic scoliosis over 40 degrees (Cobb) during the gro wth period is under discussion concerning the indication for conservative o r surgical treatment. Curve progression depends on the degree of the fronta l and sagittal deformity, vertebral rotation, rigidity of the curve, the sk eletal age, the age and sex of the patient, the familial frequency of scoli osis and the location of the curve. In scoliosis over 40 degrees progressio n is fast and the possibilities for successful conservative brace treatment are reduced during the growth period. Progression occurs more frequently i n thoracic and double major scolioses, especially in young patients (Risser sign 0 and 1). Predictive factors of a successful brace treatment are the correction of sc oliosis and rotation; deterioration of both during the brace treatment lead s to poor results. Evaluating the flexibility of the sagittal profile is im portant, as is primary correction of 30-50% in the brace during the 3 month s. Operative correction of small primary curves reduces the fusion length, operation time, and blood loss and is followed by a reduction in loading on the adjacent vertebral segments in comparison to the long fusions necessar y in more structural and double major scolioses. So far it is not possible to make an equivalent judgment of the frequency o f the "crankshaft" phenomenon and the treatment necessary in young patients (Rissersign 0 and 1)treated by dorsal instrumentation alone, but temporary brace treatment may be considered in those cases.