寰枢椎后路动态固定系统有效性的实验研究

The efficacy of posterior atlanto-axial dynamic fixation system, an experimental study

中文关键词:  寰枢椎  动态固定系统  有效性  生物力学

英文关键词:Atlanto-axial  Dynamic fixation system  Effectiveness  Biomechanics

中文摘要:

  【摘要】 目的：测试自主设计的寰枢椎后路动态固定系统的有效性。方法：根据寰枢椎的解剖特征及常规寰枢椎后路椎弓根螺钉置钉技术，设计符合寰枢椎运动方式的新型寰枢椎后路动态固定系统，并测试其有效性。将8具成人枕颈标本（C0~C4）依次按完整状态组（A组）、寰枢椎不稳状态组（B组）、寰枢椎后路动态固定状态组（C组）及寰枢椎后路椎弓根螺钉固定状态组（D组）的顺序进行测试。在三维运动试验机（KD-101）上测试4组模型的颈椎运动范围（range of motion，ROM），所有标本测试时施加1.50N·M力偶矩按前屈/后伸、左/右侧屈、左/右轴向旋转的顺序进行，取其均值，所得结果进行比较。结果：B组与A组在屈伸状态、侧屈状态和轴向旋转状态的ROM分别相差41%、44%、9%，差异有统计学意义（P<0.05）。C组与A组在屈伸、侧屈和轴向旋转状态的ROM分别相差8%、9%、9%，差异无统计学意义（P>0.05）；C组ROM与B组比较分别相差46%、50%、17%，差异有统计学意义（P<0.001）。D组固定后在屈伸、侧屈、轴向旋转状态的ROM与A组分别相差35%、46%、58%，差异有统计学意义（P<0.001）；与B组分别相差62%、70%、61%，差异有统计学意义（P<0.001）；与C组分别相差30%、41%、53%，差异有统计学意义（P<0.001）。结论：寰枢椎后路动态固定系统能够有效地限制寰枢椎的不稳，同时又能保留寰枢椎一定的屈伸、侧屈和旋转活动功能。

英文摘要:

  【Abstract】 Objectives： To test the efficacy of self-designed posterior dynamic fixation system． Methods： According to the anatomic features and routine posterior pedicle screw technique of atlanto-axial vertebrae, a posterior atlanto-axial dynamic fixation system was designed, and its effectiveness was tested. Eight human cadaveric specimens(C0-C4) under test were subgrouped as: the intact group(group A), instable group(group B), posterior atlanto-axial dynamic fixation group(group C) and posterior atlanto-axial pedicle screw fixation group(group D). The three dimensional ranges of motions of C1 relative to C2 under loading of ±1.5N·M were measured under flexion/extension, left and right lateral bending, and left and right axial rotation． The obtained data were statistically analyzed. Results： The results showed that: (1)the difference between group B and A in ROM of flexion/extension, left/right lateral bending and rotation was 41%, 44% and 9%, respectively, with significant differences(P<0.05); the difference between group C and B in ROM was 46%, 50% and 17%, respectively, with significant differences(P<0.001); the difference between group D and B in ROM was 62%, 70% and 61%, respectively, with significant differences(P<0.001). (2)the difference between group C and A in ROM of flexion/extension, left/right lateral bending and rotation was 8%, 9% and 9%, respectively, with no significant differences(P>0.05). (3)the difference between group D and A in ROM of flexion/extension, left/right lateral bending and rotation was 35%, 46% and 58%, respectively, with significant differences(P<0.001); and compared with group C, the difference was 30%, 41% and 53% respectively, which showed significant differences(P<0.001). Conclusions： The posterior atlanto-axial dynamic fixation is effective for atlanto-axial dislocation and instability, as well as maintaining the ROM of C1-C2.