As a specialist in joint pain, Guermazi has done thousands of steroid injections over decades of work. He has trained other doctors as he was trained: to believe that the injections are safe as long as they aren’t overused. But now he has come to believe that the procedure is more dangerous than he knew. And he and a group of his Boston University colleagues are raising a warning flag for doctors and patients alike.

Millions of times every year, people with joint pain allow doctors to run a needle through their skin, then their muscle, then their tendons, and into the fluid-filled space of a painful joint to calm inflammation. Such inflammation can be the result of many types of injury or disease, but most commonly it is the result of gradual wear and tear known as osteoarthritis, in which the cartilage diminishes, the space between the bones narrows, and eventually bones start to rub on one another. At that stage, a person may need a surgical joint replacement. The progression of the disease itself can’t be reversed with drugs, so medical treatment is aimed at easing pain and maximizing mobility. Steroid injections are one of the chief ways this is attempted.

In the journal Radiology this week, Guermazi and his colleagues at Boston University published a study of 459 patients at their hospital who got injections, in the hips or knees, in 2018. Of those patients, 8 percent had complications that worsened the state of their joints. In some cases, the arthritis actually sped up. Others developed small fractures under the cartilage or had complications that compromised the blood supply to bone. In the worst cases, patients had what Guermazi and his colleagues described as “rapid joint destruction.”

Patterns of harm can be slow to emerge in medicine, and causal relationships are difficult to prove. But these findings build on a gradual accretion of evidence challenging the widespread use of steroid injections. In 2015, Cochrane Musculoskeletal did a meta-analysis to see if the intervention was even helpful. After collating data from 27 knee-arthritis trials carried out around the world, the authors concluded that the quality of evidence was low and overall inconclusive. Some of the studies they analyzed found small to moderate improvements in pain and physical function, but the results were not statistically reliable. Whether there is truly any positive effect, the authors concluded, is “unclear.”

Since then, the role of the placebo effect in steroid injections has gotten attention. In 2017, rheumatologists at Tufts University and Boston University did a randomized controlled trial in people with knee pain. A control group got a “sham” injection that contained no steroids. In what became a bombshell paper in the journal JAMA, people with knee arthritis reported that their pain was no different if they received injections of steroids or saline. What’s more, the people who got the steroid injections saw more erosion in the cartilage in their knees.