Biomechanical changes of degenerated adjacent segment and intact lumbar spine after lumbosacral topping-off surgery: A three-dimensional finite element analysis

Previous studies have revealed positive effect of Topping-off technique on upper adjacent segment after fusion surgery, while for the cases with fusion surgery on L5-S1 segment, owning maximal range of motion, and preexisting degenerated upper adjacent disc, it is necessary to clarify the superiority of Topping-ff technique and the effect exerted on the lumbar spine.