Funding for this research was provided by:
Stockholms Läns Landsting (-)
Karolinska Institutet (-)
Swedish Society of Spinal Surgeons (-)
Article History
Received: 2 November 2017
Revised: 10 February 2018
Accepted: 27 February 2018
First Online: 9 March 2018
Compliance with ethical standards
:
: Peter Elkan, Tobias Lagerbäck, Hans Möller, and Paul Gerdhem declare that they have no conflict of interest.