Extraforaminal ligament attachments of human lumbar nerves

• Published in: Spine (Philadelphia, Pa. 1976) Vol. 30; no. 6; pp. 601 - 605
• Main Authors: KRAAN, G. A, DELWEL, E. J, HOOGLAND, P. V. J. M, VAN DER VEEN, M. R, WUISMAN, P. I. J. M, STOECKART, R, KLEINRENSINK, G. J, SNIJDERS, C. J
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA Lippincott 15-03-2005; Hagerstown, MD
• Subjects: Aged, 80 and over; Biological and medical sciences; Cadaver; Cerebrospinal fluid. Meninges. Spinal cord; Cranial nerves. Peripheral nerves. Autonomic nervous system; Dura Mater - anatomy & histology; Humans; Injuries of the nervous system and the skull. Diseases due to physical agents; Ligaments, Articular - anatomy & histology; Lumbar Vertebrae - innervation; Lumbosacral Region; Medical sciences; Nervous system (semeiology, syndromes); Neurology; Neurosurgery; Spinal Nerve Roots - anatomy & histology; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Traumas. Diseases due to physical agents; Zygapophyseal Joint - innervation; Human; Ligament; Nervous system diseases; intervertebral disc; Vertebral canal; Lumbar spine; Central nervous system disease; Intervertebral foramen; Spinal cord disease; extraforaminal ligaments; Spinal nerve
• ISSN: 0362-2436; 1528-1159
• DOI: 10.1097/01.brs.0000155403.85582.39

An anatomic study of the extraforaminal attachments of the lumbar spinal nerves was performed using human lumbar spinal columns.
To identify and describe the existence of ligamentous structures at each lumbar level that attach lumbar spinal nerves to structures at the level of the extraforaminal region.
During the last 120 years, several mechanisms to protect the spinal nerve against traction have been described. All these structures involved are located in the spinal canal, proximal to the intervertebral foramen.
Five embalmed human lumbar spines (T12-S1) were used. Bilaterally, the extraforaminal region was dissected to describe and measure anatomic structures and their relationships. Histology was performed with staining on the sites of attachment and along the ligament.
The levels T12-L2 show bilaterally 2 ligaments, a superior extraforaminal ligament and an inferior extraforaminal ligament. The superior extraforaminal ligament emerges from the joint capsule of the facet joints and inserts in both, the intervertebral disc and the ventral crista of the intervertebral foramen, passing the spinal nerve laterally. In one specimen on level L2-L3, the superior extraforaminal ligament is not attached to the spinal nerve. The inferior extraforaminal ligament emerges from the intervertebral disc, passing the nerve medially and attaching the spinal nerve. At the levels L2-L5, the inferior extraforaminal ligaments are only attached to the intervertebral disc, not to the joint capsule. Histologically, the ligaments consisted of mainly collagenous structures.
Ligamentous connections exist between lumbar extraforaminal spinal nerves and nearby structures.