Knee osteoarthritis, a leading cause of pain and disability in older adults, occurs when flexible tissue at the ends of bones wears down. While it can’t be cured, physical therapy or anti-inflammatory medications are often prescribed to relieve pain and improve mobility.

Researchers examined data from 10 previous studies of what’s known as prolotherapy, which is often used for chronic back pain. Prolotherapy involves injecting a solution of natural irritants like sugar or sodium next to the site where soft tissue like ligaments, tendons or muscle were injured or tore away from the bone.

Results from these studies, which had a total of 529 patients, suggest that prolotherapy may be a safe way to help ease pain from knee osteoarthritis. But the evidence on the effectiveness of prolotherapy isn’t strong enough to recommend it until after other treatments fail, said senior study author Nicola Maffulli of the University of Salerno in Italy.

“There is no evidence that prolotherapy should be tried as a first line therapy,” Maffulli said by email. “It should always be part of a holistic management plan, with weight reduction, activity changes, and physiotherapy.”

Ideal patients for prolotherapy might include people with mild to moderate knee osteoarthritis who don’t get relief from medication or physical therapy, Maffulli added.