It sounds like something out of medieval times. Using leeches to treat every disease and condition known to man. But as it turns out leeches are actually very powerful for treating a wide variety of ailments including knee osteoarthritis.

Knee osteoarthritis is a degenerative joint disease that results in the breakdown of the cartilage between the joints in the knees. This leads to pain, loss of range of motion and bone damage. There appears to be several origins of knee osteoarthritis including joint deformity, repeated injury, or excess weight. There is no cure for osteoarthritis so the focus is on treatments for the pain and reduction of continued damage to the joint.

And this is where leeches come in. Leeches secrete morphine, a potent pain killer. Leeches also secrete an anticoagulant which improves blood flow to the area where the leeches are applied and an anti-inflammatory. Since inflammation is responsible for the symptoms of osteoarthritis, researchers believe that leeches might relieve pain in patients with osteoarthritis.

The U.S. Food and Drug Administration (FDA) classify leeches as medical devices and has approved them for microsurgery. The FDA is also involved in the regulation of the transport and sale of leeches. In Germany there has been an estimated 70,000 treatments a year over the last few years with four to five used for each treatment. Most of these treatments have been aimed at pain reduction in knee osteoarthritis.

Several studies have been conducted regarding the use of leeches for treating knee osteoarthritis.

One study, reported in the Annals of the Rheumatic Diseases, focused on 16 patients with an average age 68. These patients had experienced persistent knee pain for more than six months. None had suffered any knee injuries and all had x-ray evidence of osteoarthritis. These patients were already treating their knee osteoarthritis with physical therapy, relaxation, diet and exercise.

In this study, part of the group was provided traditional treatment and the rest were treated with leeches. Four leeches were applied to the knee for 80 minutes. Pain levels were measured three days before and 28 day after the treatment. The results were rapid. Treatment with leeches resulted in pain relief after three days and continued through the 28 day test period. The patients who received traditional treatment did not experience relief. There were no side effects noted from the leeches and the patients reported that the initial leech bite was mildly painful.

A larger study was conducted involving 51 patients age 40 and above with knee osteoarthritis with high pain. Four to six leeches were applied to the affected knee and were allowed to remain until they detached themselves, which took about 70 minutes. Then the patients rested the knee for 12 hours. Researchers then measured the patients' pain, stiffness and range of motion after 3, 7, 28, and 91 days.

The results were similar to the smaller study. The patients receiving leech therapy reported less pain, less stiffness, better function, and fewer total osteoarthritis symptoms through the full 91 days that the researchers followed them.

These studies give hope for alternative treatments of knee osteoarthritis for reducing pain and increasing mobility. In order to properly validate these studies additional research needs to be conducted over a longer period of time. But it appears that leeches do provide relief to knee osteoarthritis sufferers.