Degenerative Disc Disease
||The medical term for bone spurs is
osteophytes, and they represent an enlargement of the normal bony structure.
Osteophytes are a radiographic marker of spinal degeneration and are by and
large a normal finding as aging progresses.
||The bones, or vertebrae, that make
up your spine are very strong, but sometimes a vertebra can fracture just like
any other bone in your body. Vertebra fractures are usually due to conditions
such as: osteoporosis (a condition which weakens the bones), a very hard fall,
excessive pressure, or some kind of physical injury.
When a bone in the spine collapses, it is called a vertebral compression
fracture. These fractures happen most commonly in the thoracic spine (the
middle portion of the spine), particularly in the lower vertebrae of the
|| Degenerative changes in the spine
are often referred to those that cause the loss of normal structure and/or
function. The intervertebral disc is one structure prone to the degenerative
changes associated with wear and tear, aging, even misuse (e.g. smoking).
Long before degenerative disc disease can be seen radiographically, biochemical
and structural changes occur. Some of these changes are not unlike those
associated with osteoarthritis.
Over time the protein structure of the annulus fibrosis weakens and may become
structurally unsound. Additionally, hydration of the disc decreases. These
changes are linked and may lead to the disc’s inability to handle stress.
Understanding the lumbar spine carries a large portion of the body’s weight;
the stress from motion may result in a disc problem (e.g. herniation).
|| A ruptured disc is one
that has ‘herniated’ meaning the disc contents have protruded through an
opening in the wall of the disc. A Herniated Disc is categorized as a
A disc is basically two parts; a circular outer layer termed the Annulus
Fibrosis and a Nucleus Pulposus, the gel-like center of the disc. The annulus
fibrosis is made from sturdy bands of fibrous cartilage to encase the nucleus.
If the annular wall weakens, cracks, or opens the nucleus may leak out from the
Throughout the cervical, thoracic, and lumbar spine discs sit anchored
in between vertebrae. Vertebral endplates made from cartilage along with a
system of ligaments hold each disc in proper position. Therefore, discs cannot
‘slip’ out of place. These small cushions slightly bend and twist while
absorbing stress from body movement. Some types of body movement create more
disc pressure such as jumping or lifting a heavy object. The way a disc absorbs
stress and pressure is similar to a tube of toothpaste. Squeezing the tube
places the contents under pressure. If the tube encasing the paste has a weak
spot or a hole, the paste leaks out through the opening.
Certain herniations can be very painful while others cause no symptoms.
Often when a disc herniates the nucleus spreads into the spinal canal
compressing sensitive nerve roots. In addition, the nucleus releases a chemical
agent that temporarily irritates surrounding nerve structures causing
inflammation and pain.
|| The word kyphosis is
used to describe a "C"-shaped curve in the spine. A "kyphosis" curve has the
opening of the "C" in the front of the body. This type of curve is the opposite
of a "lordotic" curve in the spine. A lordotic curve has the opening facing
towards the back. The normal spine has both types of curves, but in small
amounts. These curves become a problem when they are larger than normal - the
larger the curve, the more serious the problem. Many different conditions can
lead to an excessive kyphosis.
The thoracic, or mid portion of the spine, normally has a kyphotic curve. The
curves of the spine are usually measured in degrees. A thoracic kyphosis is
normal when measured at 20-40 degrees. The cervical spine (neck) and lumbar
spine (lower back) have "lordotic" curves that face the opposite direction -
like a backward "C". When the thoracic spine curves outside of the normal
range, it creates a "hunchback" look and the shoulders slump forward. If the
cervical or lumbar spines lose their lordotic shape and start to curve forward
instead, it is an abnormal condition referred to as "kyphosis". The abnormal
forward curvature can lead to problems within the spine in addition to an
Kyphosis can have varying symptoms and degrees of severity, from minor changes
to the shape of your back and neck, to severe deformity, neurologic deficits,
and chronic pain. Kyphosis is most common in the thoracic spine, though it can
also affect the cervical and lumbar spine..
|| Radiculopathy is a a
problem that results when a nerve in the neck or back is irritated as it leaves
the spinal canal. This condition usually occurs when a nerve root is being
pinched by a herniated disc or a bone spur.
When a nerve root leaves the spinal cord and the cervical spine and it travels
down into the arm. Along the way each nerve supplies feeling to a part of the
skin of the shoulder and arm. It also supplies electrical signals to certain
muscles to move part of the arm or hand. When a nerve is irritated or pinched -
by either a bone spur or a part of the intervertebral disc - it causes problems
in the nerve and the nerve does not work quite right. This shows up as weakness
in the muscles the nerve goes to, numbness in the skin that the nerve goes to
and pain where the nerve travels. In the neck, this condition is called
cervical radiculopathy. Similarly, when a nerve leaves the spinal cord and the
lumbar spine it travels down the leg. Lumbar radiculopathy occurs when the
nerves are irritated or pinched causes numbness, weakness, or pain to travel
down the leg and/or foot.
This condition can be caused by a herniated disc, degeneration and/or bone
|| Spondylosis refers to a
defect in one of the vertebra in the lower back, usually the last vertebra of
the lumbar spine. The area of the vertebra called the pedicle is affected. The
pedicle is part of the bony ring that protects the spinal nerves, and is the
portion that connects the vertebral body to the facet joints. When a
spondylosis is present, the back part of the vertebra and the facet joints
simply are not connected to the body - except by soft tissue. It is almost as
if the back portion had been broken off and tried to heal - but never did.
Actually, there is good evidence to suspect that this is exactly what has
occurred. Spondylosis is not something people are born with, but it appears to
first show up sometime in childhood. Interestingly, boys who are football
linemen and girls who are gymnasts seem to be affected the most. The current
thought is that the spondylosis is probably a stress fracture that never
Spondylolisthesis is the term used to describe when one vertebra slips forward
on the one below it. This usually occurs because there is a spondylosis in the
vertebra on top. There are two main parts of the spine that keep the vertebrae
aligned - the disc and the facet joints. When a spondylosis occurs, the facet
joint can no longer hold the vertebra back. The intervertebral disc may slowly
stretch under the increased stress and allow the upper vertebra to slide
forward. In the vast majority of cases, the stretching only allows a small
amount of forward slip. Furthermore, there is no real danger in an adult that
the slipping will continue until the upper vertebra slips off.
|| In the normal spinal
canal, the nerve roots are contained in the thecal sac and exit between each
vertebra (foramina). The central spinal canal and the foramen contain the
thecal sac and nerve roots respectively.
The canal and foramen are formed by bony structures (vertebral body, facets,
pedicles) as well as soft tissue structures (ligamentum flavum, facet capsules,
intervertebral disc annulus). As we age, degenerative changes occur in our
spine causing narrowing of the central spinal canal area, and/or the area where
the nerve roots exit the spinal canal (foramina). One of these degenerative
changes is the formation of extra bony growths called osteophytes (bone spurs).
Additionally, the large connective "band" (ligamentum flavum) which runs along
the inside the spinal canal can become coarse and thickened also causing
narrowing of the central canal space.