Answer to the Letter to the Editor of M. A. Potts concerning “Providence nighttime bracing is effective in treatment for adolescent idiopathic scoliosis even in curves larger than 35°” by Simony A, Beuschau I, Quisth L, et al. [Eur Spine J; (2019): https://doi.org/10.1007/s00586-019-06077-z]
Firstly, we would like to thank the author of the Letter to the Editor for his kind word regarding our publication. We are very grateful that the spine community finds value in our work and takes the time to thoroughly read through the data.
Predictors for brace outcome are curve size, Risser stage and also the flexibility of the curve, as described in the study by Ohrt-Nissen et al. 2016  where an increase in curve flexibility was associated with a decrease in risk of curve progression while treating with Providence nighttime braces (PNB). The first study published comparing PNB to Boston bracing by Yrjönen et al. 2006  described 92% in brace correction in the PNB group and 50% in brace correction the group braces with Boston braces. This study has served as a guideline, and since the wear time is reduced to 7–8 h, it is essential to achieve better curve correction during part time bracing. In our study, the mean...
Compliance with ethical standard
Conflict of interest
The author declares that she has no conflict of interest.