RESUMO
Infantile idiopathic scoliosis (IIS) represents one of the most severe forms of scoliosis. At the time of skeletal maturity the untreated progressive curves are usually over 100 degrees and have an important rotational component. That is why the natural course of IIS is thought to occur until the time that patients are treated, around 10 years of age. A close follow-up is recommended in these cases and, if necessary, starting active treatment in cases of progression. Patients who started treatment at an earlier age had better results than those who started at around 2 years of age. The overall risk of complications of IIS during the treatment period using a construct with rods is 58%. This percent decreases if implant placement is delayed as much as possible until the time of the initial surgery, at around 6 years of age, besides using a double rod instead of a single rod (10 vs 27%) and limiting the number of lengthening procedures (each subsequent lengthening results in a 24% increase in the risk of complications). The complications rate is moderate, but manageable. At present the use of a double rod with scheduled serial lengthenings seems to offer better results than the use of a single rod, due to its better capacity to control the spine. Early-onset scoliosis should be distinguished from other types of scoliosis. There are relevant doubts concerning the etiology and treatment, which should be addressed specifically.