. Author manuscript; available in PMC: 2018 Jun 27.
Published in final edited form as: Spine J. 2018 Jan 31;18(5):866–879. doi: 10.1016/j.spinee.2018.01.013
This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).