Department of Orthopaedic surgery, Kochi Medical School, Kochi University, Kohasu, Oko-cho, Nankoku, Kochi 783-8505, Japan.
Arch Orthop Trauma Surg. 2012 Jun;132(6):891-5. doi: 10.1007/s00402-012-1478-7. Epub 2012 Feb 19.
Although the posterior cruciate ligament (PCL) is considered to contain not only proprioceptive but also nociceptive sensory fibers, there is a lack of information about nociceptive sensory innervation of the PCL. We hypothesized that the PCL has constant nociceptive sensory innervation, suggesting the possible source of osteoarthritic (OA) knee pain.
Innervation of the PCL was examined by immunohistochemistry with particular reference to nociceptive nerve fibers in OA knees. Sensory nerve fibers were semi-quantitatively counted in the PCL of OA knees, comparing with non-OA knees. Protein gene product 9.5 (PGP9.5) as a general neuronal marker and calcitonin gene related peptide (CGRP) as a marker for nociceptive neuron were used.
The PCLs had constant CGRP-immunoreactive (IR) nerve fibers in both OA and non-OA knees. The difference of the CGRP-IR nerve density between groups did not reach a statistical significance (p = 0.062). For PGP9.5-IR nerve fibers, however, the PCLs in OA knees were statistically less innervated than non-OA knees (p = 0.0009).
Our results showed that, in spite of a significant decrease in total innervation in OA knees, the PCLs have constant nociceptive sensory innervation. Although the relationship between the decrease in total innervations in the PCL and OA pathophysiology is still unclear, the PCL is the possible source of OA knee pain. Our results should be taken into account when examining the pain source of the OA knees and handling the PCL during total knee arthroplasty.
虽然后交叉韧带（PCL）被认为不仅包含本体感觉纤维，还包含伤害感受纤维，但关于 PCL 的伤害感受感觉神经支配的信息仍然缺乏。我们假设 PCL 具有恒定的伤害感受感觉神经支配，这表明其可能是骨关节炎（OA）膝关节疼痛的来源。
通过免疫组织化学检查 PCL 的神经支配，特别关注 OA 膝关节中的伤害感受神经纤维。在 OA 膝关节和非 OA 膝关节的 PCL 中，半定量计数感觉神经纤维。使用蛋白基因产物 9.5（PGP9.5）作为一般神经元标志物和降钙素基因相关肽（CGRP）作为伤害感受神经元标志物。
OA 和非 OA 膝关节的 PCL 均具有恒定的 CGRP 免疫反应性（IR）神经纤维。两组之间 CGRP-IR 神经密度的差异没有达到统计学意义（p = 0.062）。然而，对于 PGP9.5-IR 神经纤维，OA 膝关节的 PCL 神经支配明显少于非 OA 膝关节（p = 0.0009）。
我们的结果表明，尽管 OA 膝关节的总神经支配显著减少，但 PCL 具有恒定的伤害感受感觉神经支配。尽管 PCL 总神经支配减少与 OA 病理生理学之间的关系仍不清楚，但 PCL 可能是 OA 膝关节疼痛的来源。在检查 OA 膝关节的疼痛来源和在全膝关节置换术中处理 PCL 时，应该考虑到我们的研究结果。
