Disc degeneration &prolapse

Disc degeneration &prolapse
With normal ageing, the disc becomes dry, the annular fibers
develop fissures &small herniation of the nucleus pulposus
may occur. With time, the disc becomes narrow &osteophytes
appear at the margins of vertebral body. These changes(disc degeneration), common in elderly, are called spondylosis.
If spondylosis is severe ?displacement of facet joints ?OA
of facet joints with osteophytes that may cause narrowing of
the spinal canal &intervertebral foramen(spinal stenosis).
Note:
* Spondylosis can occur at younger age as a result of
repeated acute disc herniation (prolapse or rupture).
* Spondylosis by itself is usually symptomless but if
severe, there will symptoms of resulting facet joint
osteoarthritis, spinal stenosis & vertebral instability.

Acute disc rupture(prolapse)
The underlying cause is disturbance of hydrophilic properties
of the nucleus pulposus while the direct cause is physical stress.
Pathology:
When rupture occurs ? the fibrocartilage material of the
nucleus is extruded posteriorly &the annulus bulges posteriorly
to one side of PLL. If the rupture is complete, the disc material
will lie free in the spinal canal or intervertebral foramen.
If the rupture is central ? compression of the cauda equina.
If the rupture is posterolateral ? compression of nerve root
in the intervertebral canal.
Note: Pressure on PLL ? backache.
Irritation of nerve root ?pain in buttock, thigh &calf(sciatica).
Pressure on the nerve root ? sensory loss& motor weakness.

CF ? age: 20-45 years; the usual presentation: while lifting he develops severe backache &unable to get up. After 1-2 days, pain
is felt in the buttock & lower limb(sciatica) which ?with coughing
&straining. Later, there may be numbness or muscle weakness in
the leg &rarely, urine retention(cauda equina compression).