Understanding Disc Prolapse and Degenerative Changes in the Spine
Intervertebral discs are crucial gel-like cushions between vertebrae that absorb shock and allow spinal flexibility. Disc prolapse, wear and tear, and spondylosis are common issues, with types like focal and broad-based herniation explained. The axial localization of herniated discs and imaging methods for diagnosis are also discussed.
Download Presentation
Please find below an Image/Link to download the presentation.
The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author. Download presentation by click this link. If you encounter any issues during the download, it is possible that the publisher has removed the file from their server.
E N D
Presentation Transcript
DISC PROLAPSE AND DEGENERATIVE CHANGES
Intervertebral Discs Gel like Tissue between each vertebra fibro cartilaginous cushions serve as the spine's shock absorbing system protect the vertebrae, brain, and other structures The discs allow some vertebral motion extension and flexion.
Intervertebral Discs The disc is made up of 3 structures the (1)Nucleus pulposus, gelatinous center (2)Annulus Fibrosus. Its job is to contain the nucleus (3)Vertebral end plates that attach the disc to the vertebrae
Process of wear and tear of intervertebral discs, vertebral bodies, and facet joints is called spondylosis Commonest cause of entrapment spinal neuropathy Usual age group >60 yrs Usually asymptomatic
DISC PROLAPSE Extrusion of nucleus pulposus through posterior or posteriolateral radial tear in annulus fibrosis
TYPES Focal herniation is a herniated disc less than 90 of the disc circumference. Broadbased herniation is a herniated disc in between 90 -180 of the disc circumference. Bulging Disc is the presence of disc tissue 'circumferentially' (180 -360 ) beyond the edges of the ring apophyses and is not considered a form of herniation
AXIAL LOCALISATION OF HERNIATED DISCS Central or medial posterior longitudinal ligament is thickest in this region,disc usually herniates slightly to the left or right of this central zone. Paramedian or lateral recess PLL is not as thick in this region, this is common region for disc herniations. Foraminal or subarticular It is rare for a disc to herniate into the intervertebral foramen. 'Dorsal Root Ganglion' lies in this zone resulting in severe pain, sciatica and nerve cell damage. Extraforaminal or lateral Disc herniations in this region are uncommon.
IMAGING for disc prolapse CT SCAN Disc material is denser than CSF in thecal sac so clearly seen against epidural fat BUT, very large extrusion may be missed.
MRI Extruded fragments brighter on T2 Enhance after contrast Sometimes heavily calcified More reliable in cervical spine where there is less epidural fat
X-RAYS Non specific findings Reduction of disc space or vertebral mal alignment or normal
Axial T1-weighted image shows protrusion of a left paracentral disc with compression of left S1 root
Axial T2-weighted image shows protraction of a left paracentral disc with compression of left S1 root
CT axial.L3,4 disc space. Soft tissue mass in R. posterolateral aspect of disc encroaching into intervertebral foramen and extending lateral to it.arrow L3 N
T1W axial. L4,5 disc, disc fragment extends behind upper part of right side of body of sacrum. Displacing 1st sacral nerve root post and erodes sacral body.
L5/S1 disc space.low signal mass protruding posteriorly and to the right from the posterior disc margin.This causes only minor compresion on the anterior margin of the theca (the bright, CSF containing sac in the spinal canal). The nerve roots within the theca are visible around its posterolateral margins and are not affected. However the neural foramen on the right is obliterated - compare with the other side where the higher signal fat, and the lower signal S1 nerve root are clearly seen
Sagittal T2 weighted MRI images of 49-year male with history of radiculopathy. a. Pre-op image showing disc prolapse at C5/6 level. b,c,d are post-op images
MRI of a patient showing disc prolapse between L5 and S1 vertebra
DEGENERATIVE CHANGES osteophytosis & marginal sclerosis Mostly in lower cervical and lumbar region reactive changes Degeneration in ligaments ossification calcification
these changes occur in post. longitudinal ligament cruciform ligament ligamenta flava capsular ligament of facet joints
Also include Ossification of post. long. Ligament Retro-odontoid pseudotumor Ossification of ligamentum flavum Synovial cysts
degenerative changes are seen in Ochronosis Charcot spine Ankylosing spondylitis Rheumatoid arthritis Isolated phenomenon
X-RAYS most of the features of degeneration can be seen If, sagittal diameter of spinal canal in cervical region <10mm ..spinal cord compressed
CT SCAN / MRI Deformation of spinal & intervertebral canals CT / MRI Better visualization of neural structures MRI Differentiation from infection .MRI absent/ non-uniform high signal, irregularity/fragmentation.
Sagittal T2W contrast.ossification of post. Longitudnal ligament
SPINAL STENOSIS Most common in Achondroplasia Acromegaly
CT / MRI Spinal canal is very narrow Cross-sectional area less than 110mm No CSF signal on T2 weighted image Reduntant coiling of intradural roots above stenosis on MRI entrapment of cauda equina
Sagittal T2W ,with contrast. Stenosis of spinal canal at L4,5. no CSF signal at stenosis
POST-OPERATIVE CHANGES Post-op recurrent myelopathy / radiculopathy 2 types Discogenic Reactive
CT / MRI Discogenic Typical mass continuous with disc substance Reactive Contracting lesion standing around theca / nerve root, continuing into soft tissue.
T2W, disc higher signal than scar Recent scar enhances faster, old scar less and slowly.
