Researchers at Boston University School of Medicine (BUSM) reviewed the medical records of several hundred patients who had received corticosteroid injections for the treatment of hip or knee osteoarthritis. They found that 8 percent of the patients developed complications that sped up their arthritis and the destruction of their joint.
The use of such injections “should be seriously discussed for pros and cons,” he added. “Critical consideration about the complications should be part of the patient consent which is currently not the case right now.”
A common condition
Osteoarthritis is a chronic, degenerative condition that affects an estimated 30 million American adults. It occurs when the cartilage that protects the ends of bones degenerates over time, causing pain, swelling and stiffness in the damaged joint.
Although osteoarthritis can develop at any age, it’s most common among older adults. Knee osteoporosis, for example, affects an estimated 10 percent of men and 13 percent of women aged 60 or older in the United States.
For short-term pain relief, doctors often prescribe corticosteroid injections, which is given to reduce the inflammation that causes osteoporotic pain. The quality of evidence that this treatment works has been found to be low, however.
Although corticosteroid injections are generally considered to be safe, concern has risen in recent years that they may worsen joint damage over time, which is why most doctors usually limit the injections to three or four a year.
How the study was done
For the current study, Guermazi and his colleagues analyzed the medical records of 459 of their patients who were given a corticosteroid injection into their hip or knee during 2018. Most of the patients (307) received hip injections.
Based on doctors’ notes and X-ray and other scanning images, the researchers determined that the joints of 36 of the patients, or 8 percent, had worsened after the injections. That included 10 percent (30) of the patients who had received injections into their hip and 4 percent (six) of the patients who had received injections into their knees.
The worsening joint problems, which were detected an average of seven months after the injections, included an acceleration of the osteoarthritis (further cartilage loss), as well as bone loss and stress fractures.
The patients ranged in age from 37 to 79, and more than half of them (19) were women. Most had moderate osteoarthritis and had received one to three corticosteroid treatments.
Limitations and implications
The study has several important limitations. It involved a relatively small number of patients. Also, the findings are only observational. Guermazi and his colleagues point out that they don’t have enough information to determine if the problems they observed in those 36 patients were caused by the injections or whether the damage had already begun to occur but hadn’t been caught at the time of the injections.
Indeed, not all the patients had images taken of their joints both before and after the injections.
Still, the findings are consistent with those of a 2017 study published in the Journal of the American Medical Association (JAMA). That study, which was a randomized placebo-controlled clinical trial (considered the gold standard of medical research), found that patients with knee osteoarthritis who received corticosteroid injections experienced more cartilage loss after two years than patients who received a placebo injection of saline.
The JAMA study also found that corticosteroid injections had no effect on reducing knee pain.
FMI: You can read the current study on Radiology’s website.