Influence of posterior pedicle screw fixation at L4-L5 level on biomechanics of the lumbar spine with and without fusion: a finite element method.

The effects of a posterior PS fixation system on the biomechanics of the lumbar spine before and after fusion were investigated for all physiological motions. This model could be used as a fundamental tool for further studies, providing a better understanding of the effects of posterior PS fixation by clearing up uncertain aspects.