458 Computational Modelling of Biomechanics and Biotribology
subsidence is, indeed, a recognized problem of the current techniques for
total disc replacement (David, 2002). Accordingly, Lin et al . (2009) virtu-
ally tested different disc substitutes in a patient-speci c model of a degen-
erated (degenerated disc and spondylosis) C5–C6 spine segment. Though
simulations did not include initial distraction of the intervertebral space,
the different implants had different effective axial stiffness, leading to dif-
ferent contact stresses between the implant and the vertebrae. The most
exible substitute appeared to give favourable results, but its capacity to
maintain the disc height was 5 to 10 times lower than that of the stiffer
discs. As well ...