Facet Syndrome
This condition refers to back pain with an
origin of mechanical joint pain in the
absence of disc pathology. The facet joints
are the posterior elements of the vertebrae
which make up the dynamic motion afforded to
us in the spine. There are a pair of
superior facet joints oriented to
communicate with the inferior facets of the
vertabrae above and another inferior pair of
facet joints designed to communicate with
the superior facets of the vertebrae below.
The facet joints are synovial joints which
like any other synovial joint are
susceptible to wear and tear changes,
degeneration and arthritis. The joints are
also surrounded by a thick fibrous capsule
which is highly innervated with nerve fibers
from the posterior rami of the nerve from
the same level and the level above. Not only
do these nerves innervate the capsule, but
also the facet themselves along with the
smaller muscles of the lumbar spine such as
the multifidus, interspinous muscles and
interspinous ligament. This is one reason
why back pain can be broad, diffuse and
vague. Facet joint pain can be caused from
malalignment of the joints, instability,
joint fixation, or loading or stress of the
joints especially when the capsule is
stretched or buckeled.
The functional unit of the spine is
comprised of two adjacent vertebral bodies
separated by the disk and the posterior
structures of the vertebrae or simply the
joints. In a functional unit, the superior
joints of one vertebrae articulate or move
in parity with the inferior joints of the
vertebrae above and inferior joints
articulate with the superior facet joints of
the vertebrae below. Sounds complicated
right? It certainly is. The more complicated
a structure the more volatile it remains.
The structures and joints of the spine are
highly dynamic and require near perfect
harmony for them to function in the absence
of pain. Just like your car does not work
100% of the time and requires maintenance to
keep it running, so does your spine to
remain healthy and pain free. The reason
that statistically 90 percent of Americans
will experience lower back pain at some
point in their lives is because of the
inherent intricacies of the functional units
of our spine.
As in degenerative disc disease, the disc
between the vertebrae begins to thin causing
the facet joints behind the disc to move
closer together. This proximity increases
the load factor of the joints and can cause
facet hypertrophy. This is characterized by
swelling of the joint and associated
capsule which, if it becomes severe enough,
can irritate the nerve roots at that
particluar level. When nerve roots are
irritated and inflamed, this process
communicates through the body via the spinal
cord and brain which may turn on the
guarding mechanism of muscular spasm.
Facet Syndrome can be
very complicated and it is very important to
have a health care professional rule out
more serious conditions as lower back pain
has a variety of causes.