Biomechanica! comparison of one- and two- level cervical arthroplasty versus fusion

摘要

Purpose To analyze the biomechanics of cervical spine after one- and two-level Total Disc Replacement (TDR) and two-level Anterior Cervical Discectomy and Fusion (ACDF). Methods Seven adult human cadaveric cervical spines were biomechanically evaluated under eccentric displacement control in six mechanical modes, including flexion (Flex), extension (Ext), left bending (LB), right rending (RB), left rotation (LR) and right rotation (RR). Results In fusion-treated specimens, range of motion (ROM) at instrumented level decreased as much as 81.78%, and other levels also demonstrated big difference in ROM. In arthroplasty-treated specimens, ROM showed little difference from that of the intact state. Large motion variation happened in LB, RB and Ext after both fusion and nonfusion surgical treatments. Conclusions TDR had a more reasonable motion sharing than ACDF, especially in Flex, Ext, LR and RR. No evident influence of motion change was observed after adding an extra level of TDR.