What is Viscosupplementation?
The knee is a work horse for walking, running, jumping, climbing, and squatting among numerous other daily activities requiring it to bend over a million times a year. Like any other hinge, it requires lubrication. In a healthy knee, synovial fluid provides this lubrication and acts as a shock absorber for the joint. In a knee damaged by arthritis due to trauma, wear and tear, or rheumatologic disorders, the normal synovial fluid is diminished or thinned. The knee joint loses its lubrication and shock absorptive properties that the synovial fluid once provided.
This is where viscosupplementation comes into play. Viscosupplementation is fluid replacement therapy to replace the normal synovial fluid with Hyaluronates.
What is Hyaluronic Acid?
Hyaluronic Acid (HA) is a substance that naturally occurs in the body. It is a thick viscous substance found in synovial fluid, cartilage and skin. Viscosupplements, designed to replace the abnormal synovial fluid found in arthritic knees, are purified HA derived from either rooster combs or genetically engineered cells to add to the naturally occurring HA cells in the knee joint.
The Role of Viscosupplementation.
Viscosupplementation is a treatment option for those with osteoarthritis of the knee. It is administered through a series of injections into the joint. It is believed that by replacing the thinned synovial fluid of the arthiritic joint by HA which mimics normal, healthy synovial fluid that lubrication and shock absorption will again be provided for the joint. Increased protection of the joint and decreased pain is the expectant result.
Could You Benefit?
Viscosupplementation is considered for those with knee osteoarthritis. The typical patient has failed or had limited improvement with non-steroidal anti-inflammatory medications, analgesics, and therapeutic exercises.
Early use is desirable. It may be considered in those who are trying to delay or are simply not candidates for a knee replacement surgery. (Viscosupplementation has been used in other joints. This is typically determined on a case by case basis. Use in other joints is routinely not covered by insurance.)
How Is It Administered?
Viscosupplementation is given by direct injection into the joint. It is given in a series of 3-5 injections spaced approximately one week apart. This is performed in the clinic. Local anesthetic/ ethyl chloride spray is used for numbing prior to the injection.
Ultrasound guidance is utilized for placement of the needle to assure the medication is delivered through the capsule and into the joint space. Studies have shown that 25% of “blind injections” deliver the medication into the surrounding fat pad and not into the knee joint. The ultrasound guarantees the medication is delivered to the desired target.
Is There Any Risk?
If you are allergic to chicken products or have had any previous reactions to hyaluronates you are not a candidate. If you have an active infection at the site where the injection is to be given then you should not have the injections at that time. If you have a febrile illness of any kind it is recommended that you postpone your injections.
Otherwise, the risk for the injections are no different from any other injections and like any other injection are very low if done with the sterile techniques and care that is recommended. These include local bleeding, joint redness and swelling, infection of the surrounding skin or joint, and pain.
HA is safe and effective. Depending on the severity of the arthritis injections can be 72-75% effective for 6 months to a year. The injection series can be repeated after 6 months.
*For more information on the procedure and if it can benefit you, call our office at (205)879-8206 and schedule an appointment.