颈椎小关节切除前后的蠕变特性

背景：创伤和颈椎退变都会使颈椎丧稳定性,需手术治疗,有时需切除小关节,目前对单独切除小关节后的蠕变特性评价鲜有报道。 目的：比较正常颈椎标本和切除颈椎C5~6小关节的蠕变力学特性,确定小关节切除是否对蠕变力学特性造成影响。 方法：在日本岛津电子万能试验机上对正常和切除小关节标本进行蠕变实验,模拟人体温在(36.5±0.5) ℃的温度场下以5%/s的应变增加速度对标本施加应力,设定时间为7 200 s。采集100个数据采用三参数模型计算蠕变方程。 结果与结论：正常和小关节切除颈蠕变曲线是以指数关系变化的,在最初600 s应变变化较快,随时间延长应变缓慢上升,正常和小关节切除组7 200 s蠕变量差异显著(P < 0.05)。说明三参数模型计算简便,能很好的拟合蠕变曲线,通过这种理想化的方程,可以定量说明两组标本差异显著。 关键词：蠕变;正常;小关节切除;颈椎;曲线 doi:10.3969/j.issn.1673-8225.2012.04.007 

Creep characteristics before and after cervical facet joint excision

BACKGROUND: Trauma and degeneration of cervical vertebrae can make cervical vertebra loses stability. That need the operation treatment, and sometimes need removal of the small joint. There are few studies on evaluation of the creep characteristics after separate resection of small joint at present.  OBJECTIVE: To compare normal cervical samples with the removal of cervical C5-6 facet joint stress relaxation of the creep mechanical properties, to determine whether the removal of the facet joint have an impact on stress relaxation properties. METHODS: Creep test on the removal of the normal facet joint specimens and the normal specimens was done on Japan shimadzu electronic universal testing aircraft. Temperature of human body on (36.5±0.5) ℃ in temperature field was simulated, stress on specimens by the speed of 5%/s was imposed, the time for 7 200 s was set. Creep equation from 100 data was calculated by three-parameter model. RESULTS AND CONCLUSION: The creep curve of normal specimens and the removal of the cervical facet joint were changed by the index relationship. It changed rapidly in the initial 600 s. With the extension of the time, the strain decline into the final phase of the balance slowly. The creep had no significant difference between the normal specimens and the removal of the cervical facet joint specimens in 7 200 s (P < 0.05). The calculation of the three-parameter model is simple, can be good fit changes in the strain curve. From this ideal equation, quantitative differences between the two groups are not significant.