Two studies comparing injections commonly used to relieve the pain of knee osteoarthritis found that corticosteroid injections were associated with the progression of the disease. Osteoarthritis is the most common form of arthritis, affecting 32.5 million adults in the U.S. Knee osteoarthritis is a chronic, degenerative and progressive condition with an estimated incidence of 800,000 patients each year. More than 10% of patients with knee osteoarthritis seek noninvasive treatment for pain relief through corticosteroid or hyaluronic acid injections. In the first study, MRI was performed on all patients at the time of the injection and two years before and after....