Lumbar intervertebral disc anatomy, biomechanics and pathogenesis of nerve root compression

1. Lumbar Intervertebral Disc Anatomy,
Biomechanics and Pathogenesis of
Nerve Root Compression
By Dr Kota Gandhi
II yr PG Orthopaedics
Kamineni Institute Of Medical Sciences

9. Lumbar Spine Alignment

12. Lumbar Pedicle Anatomy

16. Ligaments

17. Ligamenta flava

18. Supraspinous Ligament and
Ligamentum Nauchae

19. Interspinous Ligament

20. Intervertebral disc

35. A healthy, well-hydrated disc will
contain a great deal of water in its
center, known as the nucleus purposes
which provides cushioning and
flexibility for the spine. Much of the
mechanical stress that is caused by
everyday movements is transferred to
the discs within the spine and the water
content within them allows them to
effectively absorb the shock.

36. At birth, a typical human nucleus
pulposus will contain about 80% water.
However natural daily stresses and
minor injuries can cause these discs to
gradually lose water as the annulus
fibrosus or the rigid outer shell of a disc,
weakens. This water loss makes the
discs less flexible and results in the
gradual collapse and narrowing of the
gap in the spinal column.

37. As the space between vertebrae gets
smaller, extra pressure can be placed
on the discs causing tiny cracks or
tears to appear in the anulus. If
enough pressure is exerted, it's
possible for the nucleus pulposus
material to seep out through the tears
in the anulus and can cause what is
known as a herniated disc.

38. As the two vertebrae above and
below the affected disc begin to
collapse upon each other, the
facet joints at the back of the
spine are forced to shift which
can affect their function.

39. Fibrocartilage replaces the gelatinous
mucoid material of the nucleus pulposus
as the disc changes with age. There
may be splits in the anulus fibrosus,
permitting herniation of elements of
nucleus pulposus. There may also be
shrinkage of the nucleus pulposus that
produces prolapse or folding of the
anulus fibrosus with secondary
osteophyte formation at the margins of
the adjacent vertebral body.

40. Thank You!