Biomechanical properties of a novel morselized bone graft cage

• Published in: Canadian Journal of Surgery 2022-12, Vol.65, p.S159-S159
• Main Authors: Toobaie, Asra, Fernandes, Renan Jose Rodrigues, Bailey, Chris, Siddiqi, Fawaz, Rasoulinejad, Parham
• Format: Article
• Language: English
• Subjects: Biomechanics
• ISSN: 0008-428X; 1488-2310

Background: Posterior lumbar interbody fusion (PLIF) is performed using various interbody spacers. Wang and colleagues (2014) created an interbody cage by compressing morselized corticocancellous bone chips. They concluded that the newly morselized bone interbody fusion (MBIF) cage can provide appropriate stiffness at the physiologic loads. The purposes of this study were to replicate Wang and colleagues study by creating the MBIF cage and in case of failure, to redesign the MBIF cage and assess its biomechanical properties in comparison with the PEEK cage. Methods: Lamina and spinous processes of fresh frozen spine segments were morselized and placed in a bullet-shaped mold and compressed with 8 kN force. When we redesigned the MBIF cage, the mold was lined with a thin layer of stainless-steel mesh acting as a scaffold. The redesigned MBIF (n = 6) and PEEK (n = 6) cages were place between 2 blocks of solid polyurethane foam, simulating healthy bone, and underwent axial compression while we recorded compressive force and displacement curve. The experiment was repeated with polyurethane foam simulating osteoporotic bone. Results: The MBIF cage collapsed under axial compression. In the healthy bone group, peak force at 3-mm displacement was significantly lower in the redesigned MBIF cage compared with the PEEK cage. At 5-mm displacement, peak force did not differ significantly between the 2 cages. At lower levels of displacement, the redesigned MBIF construct failed by loss of height of the cage, while the PEEK cage construct failed by destruction of polyurethane foam contact surface. In osteoporotic bone, peak forces at 3 and 5 mm were significantly higher in the redesigned MBIF cage than in the PEEK cage constructs. Conclusion: The results of Wang and colleagues (2014) were not reproducible in our study. The redesigned MBIF cage showed comparable biomechanical properties to those of the PEEK cage in healthy bone construct and outperformed the PEEK cage in osteoporotic bone construct. The redesigned MBIF can be a viable option instead of a synthetic cage in patients with poor bone quality.