Advances in Synthetic Grafts in Spinal Fusion Surgery

Thirty-year follow-up after interbody fusion using silicon nitride ceramic spacers.10 (A) Computed tomographic (CT) image showing silicon nitride implant with load bearing nonporous rim (arrow) and porous core conducive to early osseointegration (asterisk). (B) Sagittal CT image showing fusion mass and osteointegration. The coronal CT image shows fusion mass adjacent to the spacer and osseointegration at the bone-ceramic conjunction. (C) Left: Implant anterior translation with posterior revision. Insert: L5 to S1 demonstrating fusion, despite anterior movement of implant. Right: Lack of reaction in surrounding tissue reinforces biocompatibility of silicon nitride implant. This image is reprinted with permission from Mobbs et al.14 Copyright 2018 Elsevier Publishing Group.

Osteointegration of new bone with anorganic bone mineral (ABM)-P15 as seen on histology with toluidine blue 0.1% staining.23 (A) Proximal transition zone between transverse process and graft, ABM granules (G) with surrounding haversian canals (H) and woven bone (W). (B) Distal transition zone between nonfused graft material and fibrous tissue (lower-left). (C) Osteointegration demonstrated with HA granules within woven bone. This image was reprinted with permission from Axelsen et al.23 Copyright 2019 Springer Nature.

Peptide amphiphile nanostructure.33 (A) Graphic rendering of peptide amphiphile with representative self-assembling nanofibers. (B) Scanning electron micrograph of peptide amphiphile nanofiber in aqueous solution. This image was reprinted with permission from Silva et al.33 Copyright 2004 The American Association for the Advancement of Science.