颈椎前路钮扣钢板的研制及生物力学评价

目的:研制颈椎前路钮扣钢板内固定系统,评价其生物力学稳定性。方法:用317L不锈钢研制出颈椎前路钮扣钢板螺钉系统。取6具青年男性新鲜尸体的颈椎标本,制成5种状态脊柱功能单位(FSU)的试验模型:正常颈椎、屈曲型损伤、单纯植骨、钮扣钢板内固定、AO钢板内固定。利用脊柱三维运动分析系统测定不同状态下颈椎节段的运动范围(ROM),比较钮扣钢板内固定与AO钢板内固定对失稳颈椎的稳定作用,并摄X线片观察各种状态下颈椎的影像学改变。结果:生物力学测试表明,钮扣钢板内固定系统可以对失稳颈椎提供明显的稳定作用(P<0.01),与AO钢板内固定系统的稳定作用相比无显著性差异(P>0.05)。动态X线摄片显示,钮扣钢板内固定及AO钢板内固定均能维持植骨块的稳定,并恢复椎间隙高度及颈椎生理曲度,而单纯植骨则容易出现植骨块的移位、凸出甚至脱出。结论:钮扣钢板内固定系统具有较好的生物力学稳定性。操作简便,适合国人颈椎解剖结构及功能特点。

Design and biomechanical evaluation of anterior cervical button plate fixation system

Objective: To evaluate the biomechanical stability of self-designed anterior button-like buttressing plate fixation system. Methods: The anterior button-like buttressing plate fixation system was designed with 317L steel . Six fresh cervical spine specimens (C1-T1 ) from young male cadavers were used to establish normal contrast, flexion injury, ilial crest strut graft, button-like plate internal fixation, and AO plate fixation models. Biomechanical stability analyses were performed by testing cervical vertebral range of motion (ROM) in sequence . The dynamic radiographs were taken to observe the cervical alignment in different conditions. Results: The anterior cervical button-like plate system decreased significantly the ROM in unstable cervical spine models (P<0. 01) . The dynamic radiographs showed that both button-like plate and AO plate can augment the stability of graft constructions, but migration and dislodgement would be seen on the grafts without plate fixation . Conclusion: The anterior cervical button-like buttressing plate fixation system can provide sufficient biomechanical stability in cervical spine after anterior decompression-bone graft fusion.