Kinematic Demands of Nucleus Replacement Technology

Recent advancements in biomaterial technologies have fostered growth in alternative surgical procedures to fusion surgery for treatment of early stages of degenerative disc disease. One application of immediate interest is that of nucleus replacement (NR). Novel materials are being developed to better match the nonlinear biomechanical properties of the native tissue [1]. The effects of changing the motion segment unit (MSU) properties via surgery (nucleotomy) or the placement of an NR material, changes the work required to move the altered spine condition through a prescribed kinematic path. The closer the loading mechanics of the altered spine are to the intact spine condition, the more likely the device will restore the native properties. The objective of this study was to use a kinematics based testing methodology to evaluate compliant materials being considered for NR devices.