Segmental biomechanics after single and multi-level lumbar spine fusion

Clinical studies have reported the incidence of adjacent segment degeneration following posterior lumbar fusion over single or multiple spinal levels. Few existing biomechanical studies investigate the change in motion and stiffness of the fused and adjacent spinal joints following single versus multi-level posterior fusion. This preliminary study showed the segmental motion of spinal joints superior to a single level posterior fusion increased compared to the intact condition and this increase was greater for a two level fusion. In vitro biomechanical studies such as this can help investigate the likelihood of adjacent segment degeneration following spinal instrumented fusion procedures, and future studies will use experimental and computational methods to further understand the lumbar spine mechanics following single and dual level posterior fusion