第1齿状韧带形态特点及临床意义

Morphological characteristics of the first denticulate ligament and its clinical significance

目的观测颅颈交界处第1齿状韧带的解剖结构,探讨其临床意义。方法收集颅颈标本18具,解剖显露第1齿状韧带等结构,观察其起止、毗邻、行程及形态;HE染色,观察其组织学特点。结果第1齿状韧带出现率为100%,薄膜型50%(9例),致密型22.2%(4例),疏松型27.8%(5例);位于延髓上段脊髓侧方,纤维呈长三角形向外上方集中,在椎动脉后方跨越,在椎动脉的头侧止于硬膜并与之融合。其脊髓的附着部位于脊神经前后根之间,远端与第2~8齿状韧带融为一体,近端达延髓水平。组织学显示齿状韧带由胶原纤维组成。结论第1齿状韧带对维持脊髓位置稳定具有重要作用。齿状韧带将蛛网膜下腔分成前后两部分,脑脊液压力不平衡可导致脊髓前后部分所受的应力不等,脊髓前方可能承受更高的压力刺激从而加重或诱发脊髓前角细胞及皮质脊髓束的损伤,这可能是导致肌萎缩侧索硬化症的解剖因素之一。

Objective To observe the anatomical structure of the first denticulate ligament at the craniocervical junction and to discuss its clinical significance.Methods Eighteen cranial-neck specimens were dissected and were stripped to observe the structure of the first denticulate ligament.Its starting and finishing,adjacency,course and its morphology were observed.The histological characteristics of the ligament was detected by HE staining.Results The first denticulate ligament were found in left and right side of all specimens(occurrence rate:100%),with the membrane type in 9 cases(accounting for 50%);dense type in 4 cases(accounting for 22.2%);loose type in 5 cases(accounting for 27.8%).The first denticulate ligament was located laterally to the superior medulla oblongata,the fibers converged outwards and upward in a long triangle,crossing behind the vertebral artery and ending in the epidural and fusing with the dura mater.The attachment part on the spinal cord was located between the anterior root and posterior root of the spinal nerve,the distal part was integrated with the 2nd~8th dentate ligament,and the proximal part reached the level of the medulla oblongata.Histological result showed that the denticulate ligament was composed of collagen fibers.Conclusions The first denticulate ligament plays an important role in maintaining the stability of the spinal cord.Subarachnoid space is divided into a front part and a back part by denticulate ligament.Cerebrospinal fluid pressure imbalance can lead to different stress on the anterior and posterior parts of the spinal cord.And the anterior spinal cord may be subjected to higher pressure stimulation to aggravate or induce the injury of the anterior horn cells of the spinal cord and the corticospinal tract,which may be one of the anatomical factors leading to amyotrophic lateral sclerosis(ALS).