The biomechanical effects of Ti versus PEEK used in the PLIF surgery on lumbar spine: a finite element analysis

Abstract

Titanium (Ti) and polyetheretherketone (PEEK) are commonly used in posterior lumbar interbody fusion (PLIF). The study investigated biomechanical effects of Ti versus PEEK used as materials of cage and rods on the lumbar spine. Four different configurations of PLIF were constituted. Stiff Ti rods provided satisfactory initial stability but increased the stress on rods significantly under simulated physiological load conditions. Ti cage increased the stress on bone endplates significantly. Materials of cage and rods had insignificant effects on the nucleus pressure and facet joint force of non-instrumented segments. Further clinical studies and follow-up observations are essential for corroborating these findings.

Keywords:

• Lumbar spine
• Ti
• PEEK
• posterior lumbar interbody fusion
• finite element analysis

Disclosure statement

No potential conflicts of interest are reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant number 51575320], the Key Basic Research Project of Natural Science Foundation of Shandong Province [grant number ZR2018ZB0106], and the Key Research and Development Program of Shandong Province [grant number 2019JZZY010112].