Knee osteoarthritis occurs when the soft cartilage lining the knee joint wears away, leaving bone to rub directly on other bone. The Arthritis Foundation estimates that 14 million Americans have symptomatic knee osteoarthritis, with lifetime risk of developing the condition at 45 percent. The problem is getting worse with time; a 2017 journal article noted that the prevalence of knee osteoarthritis has doubled since the 1950s. Osteoarthritis is overall is the most prevalent joint disease and a leading source of chronic pain and disability in the United States, the article pointed out — and more than 80% of cases are knee osteoarthritis.

Common treatments include acetaminophen and nonsteroidal anti-inflammatory drugs to relieve symptoms, along with physical therapy, cortisone injections and surgeries such as joint replacement.

But a group of investigators at the University of Florida and UAB are testing a different approach.

The researchers have just launched a new clinical trial, called Pain Relief for OsteoArthritis through Combined Treatment (PROACT), said Burel Goodin, Ph.D., associate professor in the UAB Department of Psychology and co-director of the Center for Addiction and Pain Prevention and Intervention. PROACT is funded by the National Institute on Aging. It is studying whether five days of mindfulness meditation training, or five 20-minute sessions of transcranial direct current stimulation (tDCS) — or a combination of the two — can reduce pain, improve pain-related brain function and enhance participants’ ability to modulate pain.

The study also will consider racial differences in participant response. “African Americans report a higher prevalence and severity of knee osteoarthritis than non-Hispanic whites of similar ages,” Goodin noted. His prior research has helped establish that there are clear racial and ethnic disparities in pain, with African Americans experiencing greater pain severity and pain-related disability than non-Hispanic whites. In a study published in July 2019, for example, Goodin and co-authors found that poverty contributes to these differences in knee osteoarthritis pain. In their study, Non-Hispanic whites living above the poverty line reported the least severe knee pain and the best physical function, while African Americans living below the poverty line experienced the most severe knee pain and poorest physical function.

All of the participants in the PROACT study will be drawn from people experiencing painful knee osteoarthritis; half will be African Americans and half will be non-Hispanic whites.

The study aims to demonstrate whether “targeting stress and pain-related brain function” can reduce osteoarthritis-related pain, Goodin said.