Department of Orthopaedic Surgery, Chase Hand Center, Stanford University, Stanford, CA, USA.
Cells Tissues Organs. 2012;195(5):456-64. doi: 10.1159/000327725. Epub 2011 Aug 10.
Ligament innervation purportedly plays a critical role in stability, proprioception and pathology of joints with minimal bony constraints. The human thumb carpometacarpal (CMC) joint is such a joint: with a complex saddle configuration and wide circumduction, its constraint is primarily ligamentous and it is prone to osteoarthritis. CMC reconstruction is the most commonly performed arthritis surgery in the upper extremity. Little, however, is known about CMC ligament innervation. We describe a novel triple-staining immunofluorescence technique using the markers for low-affinity neurotrophin receptor p75, the pan-neuronal marker protein gene product (PGP) 9.5 and 4',6'-diamidino-2-phenylindole (DAPI) to simultaneously detect and differentiate between specific sensory nerve endings: the Pacini corpuscles, the Ruffini endings and nerve fascicles. Five primary CMC ligaments (dorsal radial, dorsal central, posterior oblique, anterior oblique and ulnar collateral ligaments) were harvested from 10 fresh-frozen human cadaver hands. Following paraffin sectioning, each ligament was stained using a triple-stain technique and imaged with fluorescence microscopy. Multidimensional acquisition permitted simultaneous capture of images at different wavelengths. Pacini corpuscles were distinguished by their distinct p75 immunoreactive capsules, and Ruffini endings by their overlapping p75 and PGP9.5 immunoreactive dendritic nerve endings. Simultaneous use of PGP9.5, p75 and DAPI immunofluorescence to analyze innervation patterns in human ligaments provides descriptive analysis of staining patterns and receptor structure as well as clues as to the proprioceptive function of CMC ligaments and the joint as a whole. Our novel findings of CMC ligament innervation augment the study of normal and pathological joint mechanics in this joint so prone to osteoarthritis.
韧带神经支配据称在具有最小骨约束的关节的稳定性、本体感觉和病理学中发挥关键作用。人类拇指腕掌（CMC）关节就是这样一个关节：具有复杂的鞍状结构和广泛的环转运动，其约束主要是韧带性的，容易发生骨关节炎。CMC 重建是上肢最常见的关节炎手术。然而，关于 CMC 韧带神经支配的知识却知之甚少。我们描述了一种新的三重染色免疫荧光技术，使用低亲和力神经营养因子受体 p75、泛神经元标志物蛋白基因产物（PGP）9.5 和 4'，6'-二脒基-2-苯基吲哚（DAPI）的标志物来同时检测和区分特定的感觉神经末梢：Pacini 小体、Ruffini 末梢和神经束。从 10 个新鲜冷冻的人尸体手中采集了 5 个主要的 CMC 韧带（背侧桡侧、背侧中央、后斜侧、前斜侧和尺侧副韧带）。进行石蜡切片后，使用三重染色技术对每条韧带进行染色，并使用荧光显微镜进行成像。多维采集允许在不同波长下同时捕获图像。Pacini 小体通过其独特的 p75 免疫反应性囊区分，Ruffini 末梢通过其重叠的 p75 和 PGP9.5 免疫反应性树突神经末梢区分。同时使用 PGP9.5、p75 和 DAPI 免疫荧光分析人类韧带的神经支配模式，提供了对染色模式和受体结构的描述性分析，以及对 CMC 韧带和整个关节本体感觉功能的线索。我们对 CMC 韧带神经支配的新发现增加了对这个容易发生骨关节炎的关节的正常和病理关节力学的研究。
