to develop spondylolisthesis. Unlike most other types of back pain which affect the
elderly, spondylolisthesis is often found in the young as it is mainly due to a congenital
defect in the vertebrae.
In the normal spine, forward displacement of a vertebral body is prevented by
engagement of its facets with those of the segment next below it. In spondylolisthesis,
there is failure of this check mechanism. The reasons for this could be:
- Facet joint arthritis resulting in slippage of one vertebra over the other.
- Stress fracture in a part of a vertebra which may cause the body of the vertebra to
disconnect from the facet joints. This results in the vertebra slipping forward over
the vertebra below it - resulting in misalignment and narrowing in the spinal
canal. An X-ray can show the degree of slippage. Stress fracture may occur due
to:
a. Genetic weakness or malformation in part of the vertebrae
b. Sports (such as gymnastics, football, and weightlifting) that place
repetitive, excessive stress on the lower vertebrae and/ or involve
hyperextension of the spine.
Sciatica
Sciatica is a symptom and not a diagnosis. It refers to the pain felt on
compression and/ or irritation of the sciatic nerve, a large bundle of nerves that
originates from the spinal cord between the fourth and fifth lumbar vertebrae and the
fifth lumbar and first sacral vertebrae (L4 – L5 and L5 – S1: This is what you will see in
your doctor’s case notes)
The sciatic nerve on each side runs down the buttock, back of the thigh and leg and
supplies the entire foot.