Erratum to: Eur Spine J DOI 10.1007/s00586-017-5033-7

Unfortunately, an author name, Carlotta Martini, was missed out in the author group of this original version. The complete corrected author group is given below.

Andrea Piazzolla1

Giuseppe Solarino1

Davide Bizzoca1

Viola Montemurro1

Pedro Berjano2

Claudio Lamartina2

Carlotta Martini2

Biagio Moretti1