Erratum to: Eur Spine J (2016) 25:679–686 DOI 10.1007/s00586-014-3746-4

The following Acknowledgments was missing in the article:

Acknowledgments This research was supported by Projects for Research and Development of Police science and Technology under Center for Research and Development of Police science and Technology and Korean National Police Agency funded by the Ministry of Science, ICT and Future Planning (Grant No. PA-C000001-2015-202), and was partly supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (NRF-2013R1A1A1012298). No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. This retrospective study was approved by the institutional review board of our hospital. Informed consent was waived because of the retrospective nature of the study.