The document discusses intervertebral discs, disc prolapse, and degenerative changes in the spine. It provides the following key points: - Intervertebral discs act as shock absorbers between vertebrae and allow some spinal motion. Discs are made up of an inner gelatinous nucleus pulposus surrounded by the annulus fibrosus. - Disc prolapse occurs when the nucleus pulposus extrudes through tears in the annulus fibrosus. Imaging like MRI and CT can detect disc prolapses and herniations. - Degenerative changes in the spine include osteophytosis, ligament calcification and ossification, and a reduction in the size of the spinal

1. DISC PROLAPSE AND
DEGENERATIVE CHANGES

2. Intervertebral DiscsIntervertebral Discs
 Gel like Tissue betweenGel like Tissue between
each vertebraeach vertebra
 fibro cartilaginousfibro cartilaginous cushionscushions
 serve as the spine's shockserve as the spine's shock
absorbing systemabsorbing system
 protect the vertebrae, brain,protect the vertebrae, brain,
and other structuresand other structures
 The discs allow someThe discs allow some
vertebral motion extensionvertebral motion extension
and flexion.and flexion.

3. Intervertebral DiscsIntervertebral Discs
 The disc is made up ofThe disc is made up of
3 structures the3 structures the
 (1) Nucleus pulposus,(1) Nucleus pulposus,
gelatinous centergelatinous center
 (2) Annulus Fibrosus.(2) Annulus Fibrosus.
Its job is to contain theIts job is to contain the
nucleusnucleus
 (3) Vertebral end plates(3) Vertebral end plates
that attach the disc tothat attach the disc to
the vertebraethe vertebrae

4.  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

5. DISC PROLAPSE
 Extrusion of nucleus pulposus through posterior or
posteriolateral radial tear in annulus fibrosis

6. 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

8.  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.

10. 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.

11. MRI
Extruded fragments brighter on T2
Enhance after contrast
Sometimes heavily calcified
More reliable in cervical spine where there is less epidural
fat

12. X-RAYS
Non specific findings
Reduction of disc space or vertebral mal alignment or
normal

13. Axial T1-weighted image shows protrusion of a left paracentral disc with
compression of left S1 root

14. Axial T2-weighted image shows protraction of a left paracentral disc with
compression of left S1 root

15. 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

16. 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.

17. 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

18. 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

19. MRI of a patient showing disc prolapse between L5 and S1 vertebra

20. DEGENERATIVE CHANGES
 osteophytosis & marginal sclerosis
 Mostly in lower cervical and lumbar region
 reactive changes
 Degeneration in ligaments
 ossification
 calcification

21.  these changes occur in
 post. longitudinal ligament
 cruciform ligament
 ligamenta flava
 capsular ligament of facet joints

22.  Also include
 Ossification of post. long. Ligament
 Retro-odontoid pseudotumor
 Ossification of ligamentum flavum
 Synovial cysts

23. degenerative changes are seen in
 Ochronosis
 Charcot spine
 Ankylosing spondylitis
 Rheumatoid arthritis
 Isolated phenomenon

24. X-RAYS
most of the features of degeneration can be seen
If, sagittal diameter of spinal canal in cervical region
<10mm…..spinal cord compressed

25. 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.

26. Sagittal T2W contrast.ossification of post. Longitudnal ligament

27. SPINAL STENOSIS
Most common in
 Achondroplasia
 Acromegaly

28. CT / MRI
Spinal canal is very narrow
Cross-sectional area less than 110mm²
No CSF signal on T2 weighted image
Reduntant coiling of intradural roots above stenosis…on
MRI… entrapment of cauda equina

29. Sagittal T2W ,with contrast. Stenosis of spinal canal at L4,5. no CSF signal at
stenosis

30. POST-OPERATIVE CHANGES
 Post-op recurrent myelopathy / radiculopathy
 2 types
 Discogenic
 Reactive

31.  CT / MRI
 Discogenic
 Typical mass continuous with disc substance
 Reactive
 Contracting lesion standing around theca / nerve root,
continuing into soft tissue.

32.  T2W, disc higher signal than scar
 Recent scar enhances faster, old scar less and slowly.

33. THANK YOUTHANK YOU