Arthritis Treatment: Local Treatment for Osteoarthritis of the Knee

Estimates state that 12% of Americans between the ages of 25 and 75 suffer from osteoarthritis. This figure is expected to rise dramatically in the future because of a number of factors. These include the increasing incidence of the disease with age, the relative lack of effective symptomatic therapies, and finally, the absence of treatments that are capable of restoring cartilage.

Of the many areas that are affected by osteoarthritis (OA), the knee appears to have garnered the most attention.

While oral therapies including various analgesics such as acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDS) are often recommended and used, these carry with them the potential for systemic toxicity.

So the trend has been to use less toxic therapies. Most of these have local effects.
For example, recent guidelines issued by the American College of Rheumatology support the use of both acupuncture as well as transcutaneous electrical nerve stimulation. (Larger electrical stimulators have also been used. While the data looks good, there has not been sufficient interest to pursue this mode of treatment. Since it is expensive, insurers are reluctant to pay.)

These are local measures that have the aim of pain relief.

The College didn't recommend topical capsaicin although many people do find this mode of treatment to be effective.

Topical NSAIDS have their proponents. The two that are currently available are Voltaren gel and Pennsaid. Both of these preparations contain diclofenac, a commonly used NSAID.

Various patches containing either diclofenac or lidocaine have been used "off-label" by some physicians to treat knee OA.

Finally, injections are frequently used for symptomatic relief for patients in whom other local measures have failed. The two different types of injections are glucocorticoids ("cortisone") and viscosupplemments. The latter are hyaluronic acid preparations that have both lubricating as well as pain-relieving properties. Local glucocorticoid injections should be administered using ultrasound guidance with sterile technique. They should not be given any more frequently than three times per year since there is animal data indicating cartilage damage ensues if glucocorticoids are given more often.

There are a number of different hyaluronates that are used by both rheumatologists as well as orthopedists. These preparations are all about the same as far as symptom relief. Like glucocorticoids, they need to be administered using sterile technique with ultrasound guidance. It cannot be overemphasized, particularly with viscosupplements, that the precise placement of the medication is critical to a good outcome. That is why ultrasound guidance is mandatory.