Compared with IIS and AIS, JIS has received the least attention in clinical field. There are many studies on the natural history of idiopathic scoliosis [
15‐
17], however few of them considered JIS alone. Fusco C [
19] conducted a retrospective cohort observational study in JIS and found that conservative treatment initiated already in childhood may favorably change the natural history of JIS with the aim of reaching a curve as far as possible from surgical thresholds. Di Felice F [
18] performed a meta-analysis and found high progression rates of 49% (95% CI = 1–97%) in IIS, 49% (95% CI = 19–79%) in a mixed group of patients with JIS or AIS, and 42% (95% CI = 11–73%) in AIS. Our study found that the Cobb angle of nine JIS patients (34.62%) in observation group increased by > 5° within one year, and their common characteristics were older age(close to 9 years old). It suggested that we should focus on JIS patients who are about to enter a rapid growth period and review them regularly. In the observation group, one third of patients' Cobb angle increase by > 5° and no patients' Cobb angle decrease by > 5° after one year's observation. This is an indication that in the natural process of JIS, few patient's Cobb angle decrease naturally, and 30% cases have the risk of aggravation. In this study, patients who received PSSE treatment achieved an improved Cobb angle not only in statistically significant but also in clinically. It proved that PSSE could be used as an effective treatment to reduce the Cobb angle of mild JIS. The increase of Cobb angle in observation group was statistically significant rather than clinically significant. It shows that JIS is progressive at a slow but real pace. Clinically significant may be found if the observation period is prolonged. Compared with the observation group, patients who received PSSE treatment achieved an improved ATR in statistically significant but not in clinically after one year treatment. According to the instruction manual of scoliometer, a change of 3 degree or more of a scoliometer measurement indicates possible curve progression. A change of 2 degree or less usually indicates only minor variation in posture. Our analysis is that ATR mainly reflects the rotation of vertebral body and the deformity of ribs. These two problems are not serious in mild JIS patients, so there is no obvious clinical significance. Overall, our findings suggest that PSSE may control or even reduce the progression of the disease. Hence, it may be important to reconsider if observation is an appropriate treatment for mild JIS.
SOSORT has reached a consensus that PSSE is an effective treatment for patients, and SOSORT experts have agreed that PSSE should consist of three-dimensional auto-correction, training in activities of daily living (ADL), stabilizing the corrected posture and patient education [
19]. In this study, PSSE treatment included two important aspects: corrective position and over-corrective training. The corrective position is suitable for the daily life. The etiology of JIS is unclear, but in JIS, the curve will cause an uneven load on the vertebra and vice-versa [
20]. The majority of the patients with JIS are students, who sit all day, and an incorrect position, especially during sitting, will increase the Cobb angle. The corrective position is an effective method to realign the spine and break this vicious cycle [
21]. Given that patients with JIS are too young to always perform the self-correction by themselves, using a rice bag as a passive way to force the spine back to the neutral alignment is an effective treatment. Combined with the over-corrective training, which is focused on the over-correction and muscle strength exercise, the Cobb angle and ATR of the patients improved in this study. Most of the studies on PSSE in idiopathic scoliosis were conducted in adolescents, because patients with AIS have the highest progressive risk during puberty. Monticone [
7] found that PSSE could reduce spinal deformities and enhance the health-related quality of life in patients with mild AIS. The effects lasted for at least one year after the intervention. Zapata [
22]enrolled 49 patients with AIS to study the effects of PSSE for one year. The results showed that the PSSE group had lesser curve progression as compared to the controls. Negrini [
23] conducted a longitudinal comparative observational multi-center study, which included 327 consecutive patients, and found that PSSE reduced the bracing rate in AIS and was more effective than standard physiotherapy. PSSEs are additional tools that can be included in the therapeutic regimen for AIS. Using these studies as a reference, we considered that compliance is the most important factor for the effectiveness of PSSE. There are many different PSSEs, and there is no consensus on the best one. Although there are very few studies on JIS, we need to actively treat JIS because all JIS cases will undergo the period of rapid growth eventually, and then suffer the high risk of progression. In this study, when patients complete the PSSE in accordance with the requirements, 16(69.57%) of them achieved a positive result(Cobb angle decreased more than 5 degree). If the spine deformity in JIS can be reduced, it will provide a better basis for AIS in the future.