Thoracic and lumbar intraforaminal ligaments.

OBJECT: The author conducted a study to investigate the anatomy of the intraforaminal ligaments of the thoracic and lumbar nerve roots and describe their anatomical relationships and functional properties. This anatomical study performed on the intervertebral foramina, intraforaminal ligaments, transforaminal ligaments, and nerve roots of the thoracic and lumbar spine was performed in human cadavers.
METHODS: The foraminal anatomy was studied in 11 whole cadavers (5 females, 6 males) previously prepared with formaldehyde, whose ages at the time of death ranged from 16 to 71 years. The thoracic and lumbar spinal columns were separated from the cervical and sacral segments en bloc using an electric band saw. The paraspinal muscles and their attachments were removed by sharp and meticulous dissection, and the thoracic and lumbar intervertebral foramina were examined under a surgical microscope. The intervertebral foraminal ligaments and nerve roots were exposed. The foraminal contents were identified and studied in detail. The intraforaminal ligaments were stained using H & E to determine ligamentous fiber.
RESULTS: Intraforaminal ligaments connect the periosteum and transforaminal ligaments to the nerve root sleeves and vessels within the fatty areolar tissue. Histologically, the ligamentous attachment of the nerve roots within the foramina consists of adipose and connective tissue.
CONCLUSIONS: The nerve roots are surrounded by intraforaminal ligaments, which may act in conjunction with the dura and periosteum to protect the nerve roots mechanically.