RT Journal Article SR Electronic T1 Editors' Introduction: Biologics and Regenerative Medicine in Intervertebral Disc Regeneration and Spinal Fusion JF International Journal of Spine Surgery JO Int J Spine Surg FD International Society for the Advancement of Spine Surgery SP 8051 DO 10.14444/8051 A1 Roger Härtl A1 Jacobus J.C. Arts A1 Hyun Bae YR 2021 UL http://ijssurgery.com//content/early/2021/04/14/8051.abstract AB