Clinical Analysis And Related Anatomic Study On Epidural Cervical Disc Extrusion

The first part of this article is to explore the clinical feature , MRI manifestation ,diagnosis and surgical treatment for the epidural cervical disc extrusion(ECDE).Method: 35 cases undergoing operation by anterior approach from January 2004 to January 2007 were approved to be ECDE and their clinical data , anterior discetomy and intervertebral bonegraft fusion , and operative effect were reviewd. Result: 28cases were sufficient follow-up in 35 cases.The mean time of follow-up was 7.8 months.The curative effect was analysed on the JOA grade method(17 grades).The clinical outcome was graded as execellent in 22 cases,good in 3 cases,effective in 1case,ineffective in 1case.89.3 percent was fine.Conclusion: ECDE is a special type of cervical disc protrution/extrusion,of which ECDE ranged from 20 percent to 30 percent. ECDE developed maybe after injuries,in short or long history, and commonly in younger than 50 years old . The patients of ECDE were younger than that of cervical spondylosis. The specific MRI manifestation could help to diagnose ECDE before operation. To relive the spinal cord compression requires operating precisely , incising the posterior longitudinal ligament and removing the extruded nucleus pulposus completely . The satisfying result showed that surgical operation was an effective treatment for ECDE.The second part of this article is to provide some anatomic data for the clinical research by observing the width, structure and distribution of the cervical posterior longitudinal ligament (PLL) in human adults. Method: Whole cervical spinal columns from C2 through C7 were from 10 Formalin-fixed human adultcadavers of Chinese origin. In 10 columns, en block laminectomy were done. The segmental widths of the cervical PLL were measured under a surgical microscope, and the measuremental results were analysed by statistics softwares. The layers, orientation and distribution of the cervical PLL and the cervical anterior interal vertebral venous plexus were observed. We also make histological observations of the cervical posterior annulus fibrosus and PLL by a light microscope. Result: The change of the widths of the cervical PLL accompanied with that of the cervical segments, but no differences were detected in PLL widths between the segmental ligment at the vertebral bodies and intervertebral discs on all levels. The cervical PLL was made up of three layers. All of three layers coverd over the back middle part of the posterior annulus fibrosus, otherwise there were only two layers covering on the back lateral-middle part of the posterior annulus fibrosus. So the lateral-middle area on the back of the cervical intervertebral disc was relatively weaker than the middle area. And the nucleus pulposus may be extrude from the ruptured cervical posterior annulus fibrosus at the lateral-middle area more easilier than at the middle area, and become sequestered nucleus pulposus in epidural space. The cervical anterior intervertebral venous plexus was embedded between the superficial and deep layers of the cervical PLL. And the cervical nucleus pulposus was surrounded by the annulus fibrosus, the shape of which was a ring . Conclusion: our experiment showed some characters of the cervical spine, and provided some anatomic acknowledge for the clinical work.