Corticosteroid injections to relieve pain in patients with knee osteoarthritis could actually be setting them back.
Two new studies have discovered that, despite the temporary relief of symptoms, the injections were associated with continued progression of the disease.
On the other hand, patients injected with another symptom reliever, hyaluronic acid, saw decreased progression of their knee osteoarthritis.
The findings were presented Tuesday at the annual meeting of the Radiological Society of North America (RSNA), in Chicago. Research presented at medical meetings should be considered preliminary until published in a peer-reviewed journal.
"While both corticosteroid and hyaluronic acid injections are reported to help with symptomatic pain relief for knee osteoarthritis, 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,"said Dr. Upasana Upadhyay Bharadwaj, a research fellow in the department of radiology at University of California, San Francisco (UCSF).
"Hyaluronic acid, on the other hand, may slow down progression of knee osteoarthritis and alleviate long-term effects while offering symptomatic relief,"she added in an RSNA news release.
The UCSF study included 210 people enrolled in the Osteoarthritis Initiative, a study that has been observing 5,000 participants with knee osteoarthritis for 14 years.
Among those included in the UCSF study, 140 received no injections, 44 were injected with corticosteroids and 26 were injected with hyaluronic acid.
Each of the participants received an MRI scan of their knee at the time of the injection, as well as two years before and two years after. The researchers assessed the patients' knee osteoarthritis using a grading system called the whole-organ magnetic resonance imaging score (WORMS), focusing on the meniscus, bone marrow lesions, cartilage, swollen joints and ligaments.
The investigators looked for osteoarthritis progression by comparing the imaging scores from the first scans to the two-year follow-up scans.
In those with the corticosteroid injections, the researchers found overall progression of osteoarthritis in the knee, specifically in the lateral meniscus, lateral cartilage and medial cartilage.
Meanwhile, the group that received hyaluronic injections showed slower progression of osteoarthritis compared to the control group with no injections, specifically in bone marrow lesions.
"Knowing the long-term effects of these injections will help osteoarthritis patients and clinicians make more informed decisions for managing the disease and the pain it causes,"Upadhyay Bharadwaj noted.
The second study was done by researchers at the Chicago Medical School of Rosalind Franklin University of Medicine and Science.
There, researchers selected 150 patients from the Osteoarthritis Initiative database, including 50 who received corticosteroid injections, 50 with hyaluronic acid injections and 50 with no injections during a three-year period.
Patients in this study received X-rays at baseline and after two years. The researchers looked for joint space narrowing, the formation of bone spurs and bone thickening around the knee cartilage.
Patients injected with corticosteroids had significantly more osteoarthritis progression, including medial joint space narrowing, when compared to both the hyaluronic acid and the no treatment groups.
"Even though imaging findings for all patients were similar at baseline, the imaging hallmarks of osteoarthritis were worse two years later in patients who received corticosteroid injections compared to patients who received hyaluronic acid injections or no treatment at all,"said researcher and medical student Azad Darbandi.
"The results suggest that hyaluronic acid injections should be further explored for the management of knee osteoarthritis symptoms, and that steroid injections should be utilized with more caution,"Darbandi said.
Dr. Jonathan Samuels, a rheumatologist at NYU Langone Health in New York City, said many factors can influence the progression of arthritis, so causation is a tricky question to definitively answer with the two studies.
"We don't have the biology to prove that the injection itself is causing accelerated damage. It's hard to connect the dots from injection to damage from this preliminary data,"he told NBC News. "But it's an important question, because it's such a common practice to be injected with steroids."
More information
The Arthritis Foundation has more on osteoarthritis of the knee.
SOURCE: Radiological Society of North America, news release, Nov. 29, 2022; NBC News