Viscosupplementation injections require precision
An experienced physician using imaging technology (typically ultrasound) should do hyaluronan injections. A precise injection is important for two reasons:
- To be optimally effective, the hyaluronate injection must be made directly into the small space of the knee joint that contains articular cartilage and joint fluid.
- If the injectable material enters the soft tissue surrounding the knee joint instead of the joint capsule, the patient may experience uncomfortable side effects.
In contrast to viscosupplementation, corticosteroid injections have a localized effect and do not require as much precision to be effective.
Viscosupplementation is an in-office procedure that usually takes less than 5 minutes:
- The patient lies on his or her back, with the knee either straight or bent at a 20- or 30-degree angle. If the doctor prefers the knee bent, a rolled up towel may be placed under the knee to prop it up at the proper angle.
- The knee will wiped down with disinfectant such as alcohol or iodine.
- The patient will be asked to relax the leg muscles; this will facilitate a successful injection and also can make the injection less painful.
- If ultrasound is being used, a gel will be applied to small area of skin near the injection site, and a technician will gently press a hand-held ultrasound transducer against the gel-covered skin. An image of the joint space will be projected onscreen for the doctor to see.
- The doctor may administer a local anesthetic, such as lidocaine, to numb the area.
- If the knee is swollen with excess fluid, the doctor may aspirate (draw out) this fluid with a needle and syringe.
- Using a new syringe, the doctor will inject a small amount (often just 2 mL) of hyaluronan, orhyaluronic acid, on one side of the kneecap.
- The injection area is cleaned and bandaged.
- The patient will be told to straighten and bend the knee several times to help spread the hyaluronate throughout the knee joint.
Following the Hyaluronic Acid Injection
If the injection is successful in reducing the patient’s pain, the patient will be prescribed physical therapy to rehabilitate the knee and surrounding muscles, and possibly supplements.
While pain is lessened patients are able to participate in muscle-strengthening physical therapy. Doing simple exercises to build and maintain muscle strength around the knee joint is serves to decrease knee osteoarthritis symptoms and slow down or halt joint degeneration. Many physicians also recommend gentle everyday exercise, such as walking 20 to 30 minutes daily.
Patients with severe pain may be prescribed pool therapy
, a gentle and effective form of strengthening.
In addition to physical therapy, an oral supplement, such as curcumin, a chemical found naturally in turmeric spice, may be recommended. There is some evidence that turmeric, and specifically curcumin, may benefit people with osteoarthritis and rheumatoid arthritis4
Viscosupplementation Brand Name Products
The United States FDA approved viscosupplementation for the treatment of knee osteoarthritis in 1997. The hyaluronic acid and hylan formulations that are manufactured for viscosupplementation are sold under the brand names Hyalgan®, Synvisc®, Gel-One®, Supartz®, Orthovisc® and Euflexxa®. Generic formulations are also available.
- Medline Plus. Turmeric. National Institutes of Health. http://www.nlm.nih.gov. Last reviewed May 12, 2012. Accessed October 5, 2012.