ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

Figure 6: The result of equivalent strain in the FEM simulations. Model type A was
made of Ti alloy. Model type C was made of PEEK. (Different scales are shown
between figures 1 and 2 to better elucidate how the implants are affected.)
6.2 Comparisons of Stress of the Model Type A and C
We analyzed the stress of the Ti alloy and PEEK artificial vertebral bodies (Figure 7).
In model type B, stress concentration had occurred in the central part of the rods. In
contrast, the stress of the rods is minimal in model type C. The reinforced rod, which
allowed for more longitudinal strain, proved to be more resistant to bending than its Ti
counterpart, which led to stress reduction.
Figure 7: The result of stress FEM simulations. Model type A is made of Ti alloy. Model
type C made of PEEK.
7. CONCLUSION
We proposed a new artificial vertebral body configured with a PEEK interbody spacer
and a reinforced rod to solve the problems of decreased inter-vertebral stability and the
occurrence of stress concentration on the vertebral body. We were able to show the
effectiveness of the design by performing an FEM analysis.
8. REFERENCE
[1] Cloward, R. B., Treatment of ruptured lumbar intervertebral discs by vertebral
body fusion, J Neurosurg, 1953, Vol.10, No.2, pp.154–168.
[2] Cloward, R. B., Posteriorlumbarinterbodyfusion updated, Clin Orthop Relat Res,
1985, Vol.193, pp.16–19.