Erratum to: Eur Spine J DOI 10.1007/s00586-013-2822-5
An error has occurred in the legend accompanying Fig. 1: the blue line represents the data for the poor outcome group and the red line, the good outcome group (not the other way round).
Footnotes
The online version of the original article can be found under doi:10.1007/s00586-013-2822-5.