Osteoarthritis, the most prevalent type of arthritis, occurs when the cartilage that cushions a joint breaks down over time, causing pain and stiffness.Two small unpublished studies, to be presented Tuesday at the Radiological Society of North America’s annual meeting, found that on average, knee arthritis advanced more quickly among patients who got corticosteroid injections than those who didn’t.Both studies assessed patients from the Osteoarthritis Initiative, a yearslong observational research project involving nearly 5,000 people with knee osteoarthritis.The researchers looked at scans that were taken at the time of the injections, as well as two years before and after, and found more severe cartilage deterioration by the two-year follow-up mark among the steroid-taking group.“But it’s an important question, because it’s such a common practice to be injected with steroids.”Dr. Jason Kim, vice president of osteoarthritis research programs at the Arthritis Foundation, said he’d want to see studies with a “much higher sample size over a longer period of time” before considering possible causal links."