Biomechanical experimental study of dynamic and constrained cervical plates

Dynamic anterio cervical plates have been introduced into clinical anterior cervical surgery as an alternative to constrained plates' to maintain the load sharing and prevent graft subsidence. However, comprehensive biomechanical evaluations comparing the two kinds of plates are rare. In this research, eighteen porcine cervical spines were potted on a material testing system (MTS) Mini858, simulating the physiological cervical movements of both intact and two-level corpectomy conditions. Vertebrae movement and intra-discal pressures were measured by a 3-D movement analysis system and micro pressure sensors, to compare the biomechanical properties of constrained and dynamic plates. The experimental data show that the dynamic plate is biomechanically advantageous for two-level corpectomy.