All recent studies confirm that the outcome of a conservative orthopaedic treatment depends on the compliance and the effectiveness of bracing measured by immediate in-brace curve correction. There is a correlation between immediate in-brace correction and biomechanical effectiveness of brace treatment in adolescent idiopathic scoliosis. In a retrospective analysis of the immediate in-brace correction obtained from a consecutive series of patients treated by the major SOSORT teams, the conclusion was that an effective brace should be able to achieve 50% correction of the curve magnitude, immediately after application.

The aim of this study is to provide a point of comparison between different braces and study the factors determining the reduction.

This is a prospective controlled cohort observational study based on ongoing database including 544 patients with AIS treated with ARTbrace from May 2013 to November 2015. Only primary curves were selected, lumbar curves Lenke 5 are excluded as treated with the short GTB brace. The SRS criteria group consisted of 141 patients with 177 curves.

Brace checking is performed 3–4 days after brace delivery with ultra-low dose EOS system.

All 141 patients was reviewed at the control: no drop out.

The mean age was 12.92 years (SD=1.39, range: 10–15). One hundred and twenty-five patients are female (88.7%).

The average initial Cobb angle was 29.62° (SD=4.6, range: 25–40°).

The average in-brace correction (percent) was 72.5% (SD=21.9, range: 29–140%).

At the thoracic level (n=98).

The average initial Cobb angle was 30.33° (SD=4.6, range: 25–40°).

The average in-brace Cobb angle was 10.04° (SD=7.1, range: −12 to 29°).

The average in-brace correction (percent) was 67.6% (SD=21.2, range: 29–140%), significant (P=0.000).

At the thoracolumbar and lumbar for double major level (n=75).

The average initial Cobb angle was 28.61° (SD=4.1, range: 20–40°).

The average in-brace Cobb angle was 6.36° (SD=6.5, range: −9 to 25°).

The average in-brace correction (percent) was 78.8% (SD=21.3, range: 40–136%), significant (P=0.000).

For the BrAIST study, average in-brace correction was 33% (n=152, range: −48 to 100%).

The in-brace correction obtained by the asymmetrical high rigid polycarbonate detorsion brace corrects at least two times more than conventional polyethylene braces.