Inexpensive splints worn at night time can reduce the pain of hand osteoarthritis, a chronic condition that affects many older people, a new study shows.

"It's a well-tolerated, safe and cheap intervention," said rheumatologist Dr. Fiona Watt.

Watt, from the Arthritis Research UK Centre for Osteoarthritis Pathogenesis at the University of Oxford, led the new study. She and her colleagues tested custom-made splints on London clinic patients who suffered painful and deforming hand osteoarthritis. In the current study, hand therapists fashioned rigid splints out of thermoplastic, and patients wore the splints nightly while sleeping for three months, Watt said.

Twenty-six patients, mostly women, were included in the study. 74 percent reported reduced pain after wearing the splints for three months, the study found.

Watt said she was surprised to see continued benefits three months after patients stopped using the splints.

The majority of the patients, 61 percent, chose to continue to use the splints when the study was completed, "which is a good sign, probably better than any statistics," Watt said.

Dr. Prosper Benhaim, hand surgery chief at UCLA Medical Center in Los Angeles, told Reuters Health he had successfully used similar splints on his patients' thumbs.

Why splinting relieves arthritic pain is not well understood, the study authors write.

Benhaim believes nighttime splints work because they reduce inflammation. Arthritis stems from a combination of inflammation and a loss of cartilage.

"It just repositions the fingers into a more relaxed position," Benhaim said.