TENS for osteoarthritis: Not enough evidence to recommend

Despite twenty years of research on the use of electrostimulation techniques (TENS) for treatment of osteoarthritis in the knee, researchers still cannot say whether it reduces pain or physical disability. This is the conclusion of a Cochrane Systematic Review of electrostimulation trials in osteoarthritis.

Osteoarthritis is the most common cause of pain and physical disability in older people. In one widely used form of treatment for the disease, called transcutaneous electrical stimulation (TENS), an electrical current is applied to the skin at the joint to stimulate the nerves and try to relieve pain.

The authors reviewed data from 18 small trials that together included 813 patients. According to their findings for physical disability, 29 out of 100 people who received TENS treatment responded to treatment, compared to 26 out of 100 people who received fake TENS treatment or took their usual treatments. There was no difference in pain relief or in the number who dropped out due to adverse effects.

"Although some people who have electrostimulation treatment for osteoarthritis of the knee show some improvement, our data suggest that this may not be greater than the improvement experienced by those who receive placebo treatment," said lead researcher, Anne Rutjes of the Institute of Social and Preventive Medicine at the University of Bern in Switzerland. "After two decades of research on the use of these methods there is still no clear evidence that they work."

Data was only available for a few small trials and many of these were of very poor quality. In particular, most did not provide enough information about the number of drop outs and some failed to make any mention at all of adverse effects. "To clarify the effectiveness of TENS as a treatment for osteoarthritis we need larger, better quality trials," says Rutjes.

The work was funded by the Swiss National Science Foundation in Switzerland.

October 6, 2009