Comparison of the bending performance of solid and cannulated spinal pedicle screws using finite element analyses and biomechanical tests

Kao Shang Shih, Ching Chi Hsu, Sheng Mou Hou, Shan Chuen Yu, Chen Kun Liaw

Research output: Contribution to journalArticle

9 Citations (Scopus)


Spinal pedicle screw fixations have been used extensively to treat fracture, tumor, infection, or degeneration of the spine. Cannulated spinal pedicle screws with bone cement augmentation might be a useful method to ameliorate screw loosening. However, cannulated spinal pedicle screws might also increase the risk of screw breakage. Thus, the purpose of this study was to investigate the bending performance of different spinal pedicle screws with either solid design or cannulated design. Three-dimensional finite element models, which consisted of the spinal pedicle screw and the screw's hosting material, were first constructed. Next, monotonic and cyclic cantilever bending tests were both applied to validate the results of the finite element analyses. Finally, both the numerical and experimental approaches were evaluated and compared. The results indicated that the cylindrical spinal pedicle screws with a cannulated design had significantly poorer bending performance. In addition, conical spinal pedicle screws maintained the original bending performance, whether they were solid or of cannulated design. This study may provide useful recommendations to orthopedic surgeons before surgery, and it may also provide design rationales to biomechanical engineers during the development of spinal pedicle screws.

Original languageEnglish
Pages (from-to)879-884
Number of pages6
JournalMedical Engineering and Physics
Issue number9
Publication statusPublished - Sep 1 2015
Externally publishedYes



  • Bending performance
  • Biomechanical test
  • Breakage
  • Cannulated pedicle screw
  • Finite element analysis

ASJC Scopus subject areas

  • Biophysics
  • Biomedical Engineering

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