Corticosteroid injections, which are often used to ease the pain of knee osteoarthritis, were linked in two studies to the disease getting worse.
Osteoarthritis is the most common type of arthritis. In the U.S., it affects 32.5 million adults. Knee osteoarthritis is a long-term, degenerative, and progressive disease that affects about 800,000 people every year. More than 10% of people with knee osteoarthritis get corticosteroid or hyaluronic acid injections to relieve pain without surgery.
Researchers in both trials selected cohorts from the Osteoarthritis Initiative, a 14-year-old multicenter, longitudinal, observational study of approximately 5,000 patients with knee osteoarthritis.
In the first study, researchers at the University of California, San Francisco looked at 210 participants in the Osteoarthritis Initiative. Seventy of them got intraarticular injections, and the other 140 were in a control group that didn’t get injections. The study lasted for two years. Out of the 70 individuals who had injections, 44 had corticosteroids and 26 had hyaluronic acid injections. Age, sex, body mass index, pain, physical activity, and illness severity matched the treatment and control groups.
All of the patients had an MRI done two years before and after the injection, as well as at the time of the injection. The meniscus, bone marrow lesions, cartilage, joint effusion, and ligaments were all taken into consideration while assessing the MRI scans for knee osteoarthritis using the whole-organ magnetic resonance imaging score (WORMS). Through a comparison of the imaging results from the first scans and the two-year follow-up scans, the researchers were able to track the course of osteoarthritis.
“This is the first direct comparison of corticosteroid and hyaluronic acid injections using the semi-quantitative, whole organ assessment of the knee with MRI,” points out lead author Dr. Upasana Upadhyay Bharadwaj.
Statistics showed that corticosteroid knee injections were linked to the overall progression of osteoarthritis in the knee, especially in the lateral meniscus, lateral cartilage, and medial cartilage.
Injections of hyaluronic acid into the knee did not seem to slow the development of osteoarthritis in the joint. Injections of hyaluronic acid slowed the course of osteoarthritis, especially in areas of bone marrow damage, compared to a control group.
“While both corticosteroid and hyaluronic acid injections are reported to help with symptomatic pain relief for knee osteoarthritis,” adds the lead author, “our results conclusively show that corticosteroids are associated with significant progression of knee osteoarthritis up to two years post-injection and must be administered with caution.”
“Hyaluronic acid, on the other hand,” according to the author, “may slow down progression of knee osteoarthritis and alleviate long term effects while offering symptomatic relief.”
In the second trial, researchers from the Chicago Medical School of the Rosalind Franklin University of Medicine and Science compared the radiographic development of osteoarthritis in individuals who had corticosteroid and hyaluronic acid injections.
“While these injections provide some patients with short-term pain relief, the effects of the injections on the progression of the disease are unknown,” adds lead author of the second study Azad Darbandi.
From the Osteoarthritis Initiative database, Darbandi’s team identified 150 individuals with identical baseline characteristics, including 50 patients who had corticosteroid injections, 50 patients who received hyaluronic acid injections, and 50 patients who were not treated during a 36-month period. The people in each group had the same gender, BMI, and X-ray results.
Knee X-rays were taken of the patients at the start of the study and again two years later. The researchers looked at the X-rays, which showed narrowing of the joint space, growth of bone spurs, and thickening of the bone around the knee cartilage.
Compared to people who got an injection of hyaluronic acid or no treatment at all, people who got corticosteroids had a lot more osteoarthritis get worse, including the narrowing of the joint space in the middle, which is a sign of the disease.
Even though baseline imaging results for all patients were comparable, according to Darbandi, individuals who got corticosteroid injections had worse imaging signs of osteoarthritis two years later than those who had hyaluronic acid injections or no therapy at all. The findings imply that additional research into hyaluronic acid injections for the treatment of knee osteoarthritis symptoms is warranted, but steroid injections should be used with greater care.
“Knowing the long-term effects of these injections,” according to Dr. Upadhyay Baradwaj, “will help osteoarthritis patients and clinicians make more informed decisions for managing the disease and the pain it causes.”
The findings of both studies were presented today at the annual conference of the Radiological Society of North America (RSNA).
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