Fig. 1

an adolescent girl, with major thoracolumbar IS at diagnosis (Cobb angle: 26°, curve apex: T12, SSMS 3, DRU(R) 8 and DRU (U) 5) (a, e). Full time Boston brace was prescribed, and the major Cobb angle kept being slowly progressive (b). The timing and magnitude of PHV was 7.7 cm/y and 12.1 years old, respectively (c). And the corresponding staging of SSMS, DRU (R) and DRU (U) were 4, 9 and 6, respectively (f). The AV decreased to − 13.5°/y by PHV, resulting in temporary curve resolution. By skeletal maturity aged 16.6 yrs., the major curve grew to 31° (d) and the brace treatment was considered successful