目的 针对传统颈椎融合器与患者解剖形貌匹配程度较低的临床问题,对一款具备高度调节功能且外形与椎体相匹配的颈椎融合器,使用有限元与体外力学实验相结合的方法对其生物力学性能进行评价。方法 按照颈椎前路解压术(ACDF)建立颈椎C4C5节段融合模型,模拟前屈、后伸、左右侧弯、左右旋转不同生理姿态,输出融合器与椎体终板的应力,3D打印制备后进行体外力学实验,探究融合器的安全性与稳定性。结果 该融合器可保持融合C4C5节段颈椎的活动度为1°~2.8°,降低至自然节段的40%~80%,在体外压缩试验中融合器的屈服载荷为2721.67±209N满足服役状态下生理载荷的最大需求。结论 所设计的高度可调融合器显示出较优的生物力学性能,且可以减少手术中的选型步骤。
Objective Aiming at the clinical problem of the low matching degree of traditional cervical fusion cage with the patient"s anatomical morphology, a cervical fusion cage with a highly regulated function and a shape matching with the vertebral body was used to evaluate its biomechanical properties by combining finite element method with in vitro mechanical experiment. Methods A cervical C4C5 segment fusion model was established according to anterior cervical discectomy and fusion (ACDF) to simulate different physiological postures of anterior flexion, posterior extension, left and right lateral flexion and left and right rotation, and the stress of the fusion cage and vertebral endplate was output. After 3D printing, an in vitro mechanical experiment was conducted to explore the safety of the fusion cage. Results The fusion cage can keep the range of motion of cervical vertebra at the fusion segment at 1°~2.8° and reduce it to 40%~80% of the natural segment. In the in vitro compression test, the yield load of the fusion cage is 2721.67±209N, which meets the maximum demand of physiological load in service state. Conclusions The designed height adjustable fusion device shows better biomechanical properties and can reduce the selection step in operation.