Koehler, Stefan Autologous bone graft versus PEKK cage for vertebral replacement after 1- or 2-level anterior median corpectomy. [electronic resource] - Journal of neurosurgery. Spine Feb 2016 - 309-314 p. digital Publication Type: Journal Article ISSN: 1547-5646 Standard No.: 10.3171/2015.5.SPINE14887 doi