Sears WR, et al. - This study was undertaken to ascertain if ‘topping-off’ lumbar fusions, using posterior dynamic stabilizing devices (PDSs) with specific biomechanical parameters, reduce the risk of adjacent segment disease (ASD). A total of 507 patients were included in the study. The data revealed an approximately 60% reduction in further surgery for ASD with the use of the PDS to ‘top-off’ posterior lumbar interbody fusion fusions. The results exhibited lower PDS device-related complications.