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Fluid Replacement
Therapy: Image Guided
Viscosupplementation
with Hyaluronates:
We bend our knees a
million times in a year. The lubricating fluid, called synovial fluid, helps
this process acting like a lubricant and shock absorber to protect your knee. To
understand viscosupplemention and its benefits, let's take a look at the normal
knee and osteoarthritis (OA).

The
knee joint is where the femur (thigh bone) and tibia (shin bone) come together.
A third bone, the triangular-shaped patella (knee cap), lies across the front of
the joint to protect it. As in our other joints, a layer of protective cartilage
covers the ends of the bones to allow smooth movement. Special to the knee are
two pads of protective tissue called menisci. The entire joint is encased is a
capsule lined with a membrane called the synovium which generates a fluid that
acts as both a lubricant and a shock absorber. This fluid is called synovial
fluid. Various ligaments and muscles support, stabilize and power the joint. Although
there are many problems associated with knee pain,
the most prevalent joint disorder is osteoarthritis. Osteoarthritis can be due
to a predisposition to its development but also often is a result of repetitive
micro traumas over many years, an injury left untreated such as a torn meniscus
and being overweight. The end result of osteoarthritis of the knee is often
severe cartilage loss resulting in significant pain particularly while weight
bearing (walking), getting up from a chair and sometimes at night.
Through this process
of progressive osteoarthritis, the components of the synovial fluid often
breakdown, resulting in diminished shock absorbing characteristics. This loss of
shock absorption results in less protection of the knee during movement. One
such component of the synovial fluid is hyaluronic acid (HA), which is
responsible for the synovial fluid's ability to lubricate and act as a shock
absorber in the knee. When one has knee OA, the concentration of HA in the
synovial fluid is reduced causing a loss of shock absorbing and lubricating
properties. This results in increased joint pain, stiffness and possibly an
onset or worsening of osteoarthritis.

What is Hyaluronic
Acid?
Hyaluronic acid (HA) is a substance natural in the body
and is present not only in the synovial fluid but also in the eyeballs, skin and
cartilage. When isolated, it is a thick, viscous solution. Viscosupplements,
which are designed to replace osteoarthritic synovial fluid with a more normal
prosthetic synovial fluid, use purified HA derived from either rooster combs or
genetically engineered cells to add to the natural HA in the knee joint.
The Role of
Viscosupplementation
Viscosupplementation is an option of treatment for
those with moderate to moderately severe osteoarthritis of the knee. Through a
series of injections, supplemental HA can be added to the knee joint. It is
believed that by replacing the osteoarthritic synovial fluid with a product made
of HA that is closer to normal synovial fluid, the patient experiences pain
relief due to the presence of a new "lubricant" in the knee that is also acting
as a shock absorber. The result is increased protection of the knee joint itself
and a soothing of the nerve endings exposed by the degraded cartilage of the
osteoarthritic knee.
Could You Benefit?
Viscosupplementation is given to people with knee
osteoarthritis who have not responded to traditional therapies, such as oral
anti-inflammatory or analgesic medications or exercise. It is also can be
considered for those who are trying to delay or simply are not candidates for
total knee replacement surgery. This treatment has not been approved for other
joints, although there are studies underway for hip arthritis.
How Is It
Administered?
Viscosupplementation
therapy is only available through injection into the knee. The injection is
given directly into the knee from a point on the side and under the kneecap.
Synvisc is a viscosupplementation product that is specifically designed to be
closest to healthy young synovial fluid and provides relief that can last for
months. It is given in a series of three injections, one each week. It can take
up to 12 weeks to take full effect.
Studies have shown that
about 25 % of blind injections have delivered the medication into fat tissue
around the knee instead of the knee joint itself. Therefore we at Pain
Management Associates perform viscosupplementation injections under fluoroscopy,
minimal x-ray in order to assure the best chance to benefit from fluid
replacement therapy.
Is There Any Risk?
If you have had any allergic reaction to any
hyaluronate preparations or are allergic to poultry products, you are not a
candidate for these injections. You also should not receive these injections if
you have an infection or skin disease around the injection area. Sometimes one
can experience some swelling, heat, redness or itching around the joint, but
this is temporary. Any reaction is usually mild and short-lived.
Does
Viscosupplemention Work?
HA viscosupplemention is a safe and effective treatment
for osteoarthritis of the knee. Depending on the severity of the knee arthritis,
these injections can be 72-75% effective for six months to a year.

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