Tensile stretching of cervical facet joint capsule and related axonal changes
Tensile stretching of cervical facet joint capsule and related axonal changes
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DOI：
10.1007/s00586-007-0562-0
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发表时间：
2008-04-01
影响因子：
2.8
通讯作者：
Cavanaugh, John M.
中科院分区：
文献类型：
--
作者：
Kallakuri, Srinivasu;Singh, Anita;Cavanaugh, John M.
本研究探讨山羊颈椎小关节囊（FJC）受到低速负荷轴突的变化。使用计算机控制的致动器对左侧C5-C6 FJC进行一系列拉伸试验，从2 mm至失效。通过立体成像系统监测背侧的FJC应变。收获拉伸（n = 10）和未拉伸（n = 7）的胶囊，并通过银浸渍法处理连续切片。平均峰值驱动器位移为21.3 mm（范围：12-30 mm）。包含胶囊不同区域的平均峰值应变为72.9 +/-7.1%。在70%的拉伸胶囊中观察到胶囊完全失效。切片的银浸渍显示在囊的所有区域中的神经纤维和神经束。对轴突的数字显微照片的盲法分析显示，在拉伸的FJC中具有统计学显著数量的具有不均匀口径的肿胀轴突。还观察到具有末端回缩球、偶尔出现串珠状外观或空泡的轴突。拉伸FJC超出生理范围可能导致轴突形态改变，这可能与继发性或延迟性轴突切开术变化有关，类似于在轴突受到拉伸和剪切的中枢神经系统损伤中观察到的变化。这些可能导致神经性疼痛，并可能与颈部扭伤事件后的颈部疼痛相关。
This study examines axonal changes in goat cervical facet joint capsules (FJC) subjected to low rate loading. Left C5-C6 FJC was subjected to a series of tensile tests from 2 mm to failure using a computer-controlled actuator. The FJC strain on the dorsal aspect was monitored by a stereo-imaging system. Stretched (n = 10) and unstretched (n = 7) capsules were harvested and serial sections were processed by a silver impregnation method. The mean peak actuator displacement was 21.3 mm (range: 12-30 mm). The average peak strain encompassing various regions of the capsule was 72.9 +/- 7.1%. Complete failure of the capsule was observed in 70% of the stretched capsules. Silver impregnation of the sections revealed nerve fibers and bundles in all the regions of the capsule. A blinded analysis of digital photomicrographs of axons revealed a statistically significant number of swollen axons with non-uniform caliber in stretched FJCs. Axons with terminal retraction balls, with occasional beaded appearance or with vacuolations were also observed. Stretching the FJC beyond physiological range could result in altered axonal morphology that may be related to secondary or delayed axotomy changes similar to those seen in central nervous system injuries where axons are subjected to stretching and shearing. These may contribute to neuropathic pain and are potentially related to neck pain after whiplash events.