Comparison of polyetheretherketone versus silicon nitride intervertebral spinal spacers in a caprine model

Abstract

Polyetheretherketone (PEEK) is commonly used as a spinal spacer for intervertebral fusion surgery. Unfortunately, PEEK is bioinert and does not effectively osseointegrate into living bone. In contrast, comparable spacers made of silicon nitride (Si N ) possess a surface nanostructure and chemistry that encourage appositional bone healing. This observational study was designed to compare the outcomes of these two biomaterials when implanted as spacers in an adult caprine model. Lumbar interbody fusion surgeries were performed at two adjacent levels in eight adult goats using implants of PEEK and Si N . At six-months after surgery, the operative and adjacent spinal segments were extracted and measured for bone fusion, bone volume, bone-implant contact (BIC) and soft-tissue implant contact (SIC) ratios, and biodynamic stability. The null hypothesis was that no differences in these parameters would be apparent between the two groups. Fusion was observed in seven of eight implants in each group with greater bone formation in the Si N group (52.6%) versus PEEK (27.9%; p = 0.2). There were no significant differences in BIC ratios between PEEK and Si N , and the biodynamic stability of the two groups was also comparable. The results suggest that Si N spacers are not inferior to PEEK and they may be more effective in promoting arthrodesis. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 00B: 000-000, 2018.

Silicon Nitride, a Bioceramic for Bone Tissue Engineering: A Reinforced Cryogel System With Antibiofilm and Osteogenic Effects

“…Osteogenic effects of SiN were confirmed in several in vitro tests with different cell types, such as human osteosarcoma SaOS-2 cells ( Pezzotti et al, 2016 ; Pezzotti et al, 2017b ; Zanocco et al, 2019 ), mouse bone marrow stromal cells (BMSCs) ( Pezzotti et al, 2017a ), and human BMSCs ( Amaral et al, 2002 ). The effectiveness of SiN was further confirmed in several in vivo studies using a goat lumbar interbody fusion model ( Kersten et al, 2019 ), a rat calvarial defect model ( Webster et al, 2012 ), and a murine tibial implant model ( Ishikawa et al, 2017 ). However, the brittleness and lack of resilience, common disadvantages of ceramic biomaterials, make it problematic to use SiN alone as a scaffold.…”

Highly Effective Bone Fusion Induced by the Interbody Cage Made of Calcium Silicate/Polyetheretherketone in a Goat Model

“…In interbody fusion, another critical determinant is the new bone formation around the intervertebral fusion cage. , A bioactive material should have the capacity to stimulate biological response to realize effective osteogenesis. , The regenerative ability of the material could be improved by optimizing composition or incorporating bioactive ions that play a pivotal role in osteogenic process. In our previous study, we demonstrated that the presence of CS incorporated into PEEK could effectively release the bioactive Ca 2+ and Si 4+ ions which exerted a positive influence on the osteogenic differentiation of preosteoblasts in vitro .…”

Silicon Nitride as a Biomedical Material: An Overview

“…New medical devices should be compared to the gold standard for their clinical performance. Kersten et al [ 73 ] compared the bone formation ability of Si 3 N 4 and PEEK in lumbar interbody fusion surgeries using a caprine model. The results demonstrated that Si 3 N 4 spacers were not inferior to PEEK in bone-implant contact (BIC) and biodynamic stability, and they were superior in promoting arthrodesis.…”