Based on the two radiologists’ reports, the study found that 22–24% of patients with hip OA who received steroid injections showed new osteonecrosis compared with 9% of patients in the hip control group and 5% in the control group of patients who received shoulder steroid injections.3
In specific, the radiologists found bone collapse in the head of the femur bone in 15–17% of the patients in the intervention group compared with 4% in the hip control group and 2% in the control group of patients who received shoulder steroid injections.3
Commenting in a press release, Dr. Chang noted the rapid changes in bone in the intervention group. “Changes due to osteoarthritis, such as narrowing in the space between joints and the developments of bony proliferations, typically develop slowly over time. When reading follow-up radiographs of patients who had received a hip injection, we noticed changes had developed rapidly in some patients.”4
Caution Warranted: More Data Needed
Saying the study provides noteworthy observations about the potential effects of steroid injections in the hip, Sharon L. Kolasinski, MD, professor of clinical medicine, Division of Rheumatology, Penn Musculoskeletal Center, Perelman School of Medicine, University of Pennsylvania, emphasizes that more information is needed to understand which patients may be at risk for the deleterious effects noted in the study.
“We need to know exactly who the population is that is at risk and how big that risk is,” she says.
Dr. Kolasinski emphasizes that the study offers an important observation that has not been made in previous studies. “There hasn’t been a previous study that looked at radiographic change following hip injection,” she says. “If you don’t look for it, you may miss it.”
Of note, she says, were the rapid changes to bone in the hip patients who received the injections. “It is really eye [opening] to see the percentages of patients with radiographic progression over a relatively short period of time following these injections,” she says. “Further, the percentage of patients experiencing osteonecrosis or new collapse is quite remarkable.”
In her comments in the press release, Dr. Chang noted that the patients with hip OA who received the steroid injections had disease that was severe enough to warrant the injections and therefore, compared with the control groups, were prone to faster progression of bony changes.
“We need to look at what’s going on with the steroid/anesthetic injectate and osteoarthritis patients to determine what’s causing the changes that occur in some patients,” she says in the press release.4