School of Engineering, University of Vermont, Burlington, VT 05405, USA.
Spine J. 2010 Dec;10(12):1098-105. doi: 10.1016/j.spinee.2010.09.015. Epub 2010 Oct 23.
Needle puncture of the intervertebral disc (IVD) is required for delivery of therapeutic agents to the nucleus pulposus and for some diagnostic procedures. Needle puncture has also been implicated as an initiator of disc degeneration. It is hypothesized that needle puncture may initiate IVD degeneration by altering microscale mechanical behavior in the annulus fibrosus (AF).
Quantify the changes in AF microscale strain behavior resulting from puncture with a hypodermic needle.
Cadaveric IVD tissue explant study.
Annulus fibrosus explants from bovine caudal IVDs that had been punctured radially with hypodermic needles were loaded in dynamic sinusoidal shear while being imaged with a confocal microscope. Digital image analysis was used to quantify local tissue strain and damage propagation with repeated shearing.
Needle puncture changed the distribution of microscale shear strains in the AF under load from homogenous (equal to far field) to a distinct pattern of high (4× far field) and low (0.25× far field) strain areas. Repeated loading did not cause further growth of the disruption beyond the second cycle.
Needle puncture results in a drastic alteration of microscale strain behavior in the AF under load. This alteration may directly initiate disc degeneration by being detrimental to tissue-cell mechanotransduction.
为了将治疗剂递送到髓核并进行某些诊断程序，需要对椎间盘（IVD）进行针穿刺。针穿刺也被认为是椎间盘退变的启动因素。据推测，针穿刺可能通过改变纤维环（AF）的微尺度力学行为来引发 IVD 退变。
定量评估皮下针穿刺对 AF 微尺度应变行为的改变。
尸体椎间盘组织外植体研究。
使用共聚焦显微镜对牛尾椎间盘的纤维环外植体进行径向皮下针穿刺，然后在动态正弦剪切下加载。数字图像分析用于量化局部组织应变和损伤在重复剪切下的传播。
针穿刺改变了 AF 在载荷下的微尺度剪切应变分布，从均匀（等于远场）变为明显的高（4 倍远场）和低（0.25 倍远场）应变区模式。重复加载不会导致破坏在第二个周期后进一步扩大。
针穿刺导致 AF 在载荷下的微尺度应变行为发生剧烈变化。这种变化可能通过对组织细胞的机械转导有害而直接引发椎间盘退变。
