I. Definition and etiology of idiopathic scoliosis Idiopathic scoliosis is a scoliosis and rotational deformity of the spine without any other developmental or neuromuscular abnormalities of the spine itself. It is the most common type of scoliosis, accounting for approximately 70% of cases. Much research has been conducted on the etiology of idiopathic scoliosis, but it remains unclear. Possible etiologies include connective tissue abnormalities, central nervous system alterations, endocrine disorders, growth asymmetry, and muscle strength imbalances. Although the etiology is not certain, it is certain that it is related to genetic and genetic factors. Treatment of idiopathic scoliosis requires the physician to have a deep understanding of its etiology, natural course, and the flexibility of various treatment options. Although the definition of idiopathic is more precise, there is a growing understanding of its etiology and natural course. Recent studies of genes have helped to uncover how genetic changes play a role in the development of idiopathic scoliosis. Studies of the natural course have provided insight into the risk factors for scoliosis exacerbation to guide their treatment choices. Bracing remains an important non-surgical treatment, and some new types of bracing have given physicians and patients more options. Surgical treatment has improved greatly over the years, with leaps and bounds in surgical techniques as understanding of scoliosis has grown, surgical and anesthetic methods have improved, and instruments have been updated. The adoption of these new techniques has led to better orthopedic results, fewer complications, and faster postoperative recovery. Scoliosis can be detected in a timely manner during screening of adolescents, a small percentage of whom may progress to more severe deformities. The significance of early and timely treatment of these patients is to: reduce cardiopulmonary complications that may lead to death; reduce low back pain in adulthood; improve appearance, reduce the patient’s psychological burden, and restore his or her social identity; and early treatment is simple and less costly. II. Prognosis of idiopathic scoliosis The main concern of patients with scoliosis is the aggravation of the spinal deformity, and most of the treatment decisions are based on preventing or treating the aggravation of scoliosis. Knowledge of the natural course of idiopathic scoliosis can help us to compare treated patients with untreated patients, determine the effectiveness of that treatment, effectively select their treatment, and estimate their prognosis. In general, less than 1% of all screened school children require treatment, and 10% of those with positive screening results require treatment. In adolescent patients who are not yet skeletally mature, there are two main factors that influence the natural course of scoliosis: the growth potential of the spine and factors related to the scoliosis itself. Scoliosis itself includes the type and size of scoliosis, with double curves being more likely to worsen than single curves, and scoliosis being more likely to progress with greater angulation. Factors related to growth potential include age, gender, age of menarche in girls, and Risser’s sign. The younger the age at first diagnosis, the more likely scoliosis will develop; girls are more likely to develop than boys and are most likely to develop before menarche; and the lower the Risser’s sign at first diagnosis, the more likely it is to develop. Risser’s sign and scoliosis angle on standing radiographs can be used as indicators to assess the risk of scoliosis progression. Younger, undeveloped patients with greater angulation are at greater risk of progression and are important in the evaluation of a patient with scoliosis. The above study may provide a rough answer to the question often asked by patients, “What is my risk of scoliosis progression” and suggest what treatment may be needed. Idiopathic scoliosis: 1. Infantile type: scoliosis from 0 to 3 years of age, mainly in the thoracic spine, mostly in boys, mostly protruding to the left. There are two possibilities for its development: the first one will reduce or stop developing on its own as the child grows up, without treatment, accounting for about 85%; the second one will gradually worsen and require active treatment, accounting for about 15%. 2. Juvenile type: aged between 4 and 10 years old, accounting for about 15% of all cases of idiopathic scoliosis, with scoliosis more convex to the right side and more common in females. In general, juvenile scoliosis is at greater risk of progression and often requires more surgical treatment than the adolescent type. 3. Juvenile type: scoliosis above the age of 10 is the best age for surgical treatment and accounts for the majority of surgical cases, partly developed from the juvenile type. IV. Treatment 1. Non-surgical treatment Most patients are found to have very mild scoliosis when their bending is detected, and there is no significant progression even after follow-up throughout the growth period. For scoliosis less than 20°, it should be reviewed every 4-6 months if the skeleton is not yet mature and before the first menstrual period. If the scoliosis is more than 20° or 25°, or if the scoliosis progresses more than 5° between reviews, then bracing should be performed. Physical therapy remains controversial, and Stone used a prospective study to look at the effectiveness of physical therapy and found it to be ineffective in preventing scoliosis progression and noted poor compliance with physical therapy. In general, a specific physical therapy approach is not effective for progressive scoliosis. The indications for brace use are not entirely uniform. In general, it is indicated for patients with progressive scoliosis and immature bones. For scoliosis greater than 20° or progressing more than 5° at the time of review, those with Risser’s sign grade II or less should be braced. For scoliosis between 35° and 40°, bracing can still be tried, while when the scoliosis is greater than 45°, surgery should be performed because it may continue to progress in adulthood. 2. Surgical treatment Surgical treatment of scoliosis has developed relatively rapidly over the past 50 years, especially in the last 10-15 years, with the advancement of new technologies. From the early 1900s to the late 1950s, the surgical approach was posterior fusion with postoperative cast fixation. harrington’s use of fusion under internal spinal fixation is a major advance in scoliosis surgery. harrington’s internal fixation system uses bracing and compression as the primary method of correcting spinal deformities, with the advantage that scoliosis can be orthoped and the patient can be protected by bracing The advantage is that scoliosis can be orthoped and the patient can move early under the protection of a brace without the need for strict cast fixation. In the late 1970s, Luque pioneered the concept of segmental fixation by using fixation rods and sublaminar wires for internal fixation, and for the first time applied translation and de-rotation techniques instead of bracing as the basic approach to scoliosis correction. By the mid-1980s, segmental fixation had evolved to include a variety of hook-and-rod internal fixation systems. After the 1990s, scoliosis orthosis and stabilization techniques were greatly improved with the advent of multisegmental fixation using pedicle screws. Initially used primarily in the lumbar and thoracolumbar regions, the pedicle screw was extended to the thoracic spine by Suk. With the gradual application of multisegmental fixation, orthopedic results have become more satisfactory and patients can have early removal of external fixation and bracing, which is particularly important for the more self-aware adolescent. The new generation of internal fixation systems has increased our ability to obtain early stabilization after orthopedic surgery, but the basic concepts of obtaining a strong fusion and stable spinal balance are not fundamentally different than those of earlier spinal fusion, and performing meticulous decortication and implant fusion remains essential to obtaining long-term stability and good results in the spine. Autologous bone grafting is considered the gold standard for obtaining a strong fusion, and allogeneic bone is also considered a good substitute for autologous bone grafting. Bone grafting from the posterior superior iliac crest can result in a variety of complications, including: arterial injury, cosmetic deformity, hematoma, infection, pain, fracture, and sacroiliac joint injury, whereas allograft bone can avoid these complications with an unlimited amount of bone grafting. Along with the continuous advancement of internal fixation systems, perioperative management has also evolved. Improvements in anesthesia techniques and postoperative management have made more complex procedures possible, including combined anterior and posterior procedures in one stage. For routine scoliosis orthopedics, the postoperative hospital stay has also been reduced from the initial weeks to at least 1 week.