Department of Anatomy, Dalian Medical University, 9 West Section, Lushun South Road, Dalian, Liaoning Province, 116044, China.
Department of Anatomy, Dalian Medical University, 9 West Section, Lushun South Road, Dalian, Liaoning Province, 116044, China; Dalian Hoffen Preservation Technique Institution, No.36, Guangyuan Street, Lushunkou Economic Development Zone, Dalian, 116052, China.
Spine J. 2018 Jun;18(6):1081-1087. doi: 10.1016/j.spinee.2018.02.006. Epub 2018 Mar 15.
Studies over the past 20 years have revealed that there are fibrous connective tissues between the suboccipital muscles, nuchal ligament, and cervical spinal dura mater (SDM). This fibrous connection with the SDM is through the posterior atlanto-occipital or atlantoaxial interspaces and is called the myodural bridge (MDB). Researchers have inferred that the MDB might have important functions. It was speculated that the function of MDB might be related to proprioception transmission, keeping the subarachnoid space and the cerebellomedullary cistern unobstructed, and affecting the dynamic circulation of the cerebrospinal fluid. In addition, clinicians have found that the pathologic change of the MDB might cause cervicogenic or chronic tension-type headache. Previous gross anatomical and histologic studies only confirmed the existence of the MDB but did not reveal the fiber properties of the MDB. This is important to further mechanical and functional research on the MDB.
Multiple histologic staining methods were used in the present study to reveal the various origin and fiber properties of the MDB. Muscles and ligaments participating in forming the MDB at the posterior atlanto-occipital or atlantoaxial interspaces were observed, and the fiber properties of the MDB were confirmed. The present study provides a basis for speculating the tensile force values of the MDB on the SDM and a morphologic foundational work for exploring the physiological functions and clinical significances of the MDB.
Anatomical and histologic analyses of suboccipital structures that communicate with the SDM at the posterior atlanto-occipital or atlantoaxial interspaces were carried out.
Multiple histologic staining methods were used to evaluate the histologic properties and composition of the MDB at the posterior atlanto-occipital or atlantoaxial interspaces in five formalin-fixed head-neck human specimens.
The results show that the MDB traversing the atlanto-occipital interspace originated from the rectus capitis posterior minor (RCPmi). The MDB traversing the atlantoaxial interspace originated mainly from the RCPmi, rectus capitis posterior major, and obliquus capitis inferior. These fibers form the vertebral dural ligament in the atlantoaxial interspace and connect with SDM. The MDB is mainly formed by parallel running type I collagen fibers; thus, suboccipital muscle could pull SDM strongly through the effective force propagated by the MDB during head movement.
Myodural bridge is mainly formed by parallel running type I collagen fibers; thus, it can transmit the strong pull from the diverse suboccipital muscles or ligaments during head movement. The results of the present study will serve as a basis for further biomechanical and functional MDB research.
过去 20 年来的研究表明，枕下肌、项韧带和颈脊髓硬脊膜（SDM）之间存在纤维结缔组织。这种与 SDM 的纤维连接是通过后寰枕或寰枢关节间隙进行的，称为肌硬膜桥（MDB）。研究人员推断 MDB 可能具有重要功能。有人推测 MDB 的功能可能与本体感觉传递、保持蛛网膜下腔和小脑延髓池通畅以及影响脑脊液的动态循环有关。此外，临床医生发现 MDB 的病理变化可能导致颈源性或慢性紧张型头痛。以前的大体解剖学和组织学研究仅证实了 MDB 的存在，但并未揭示 MDB 的纤维特性。这对于进一步研究 MDB 的力学和功能非常重要。
本研究采用多种组织学染色方法，揭示 MDB 的多种起源和纤维特性。观察参与后寰枕或寰枢关节间隙形成 MDB 的肌肉和韧带，并证实 MDB 的纤维特性。本研究为推测 MDB 对 SDM 的拉伸力值提供了依据，为探索 MDB 的生理功能和临床意义奠定了形态学基础。
对后寰枕或寰枢关节间隙与 SDM 相通的枕下结构进行解剖学和组织学分析。
采用多种组织学染色方法，对 5 例福尔马林固定的头颈部人体标本后寰枕或寰枢关节间隙的 MDB 进行组织学特性和组成评估。
结果表明，穿过寰枕间隙的 MDB 起源于头后小直肌（RCPmi）。穿过寰枢关节间隙的 MDB 主要起源于 RCPmi、头后大直肌和头下斜肌。这些纤维在寰枢关节间隙形成椎骨硬脊膜韧带，并与 SDM 相连。MDB 主要由平行排列的 I 型胶原纤维组成；因此，在头部运动过程中，枕下肌可以通过 MDB 有效传递的力，强有力地牵拉 SDM。
MDB 主要由平行排列的 I 型胶原纤维组成，因此可以在头部运动过程中传递来自各种枕下肌肉或韧带的强大拉力。本研究的结果将为进一步的生物力学和功能 MDB 研究提供基础。
