The common practice of treating knee pain with corticosteroid injections may actually help speed up the progression of arthritis, two studies have found. But injections of hyaluronic acid — a steroid- and opioid-free substance — may be protective, the researchers say.
Osteoarthritis affects approximately 32 million adults in the United States. About 10% of people whose knees are affected receive corticosteroid or hyaluronic acid injections to relieve associated pain, the researchers reported. Corticosteroids are a type of anti-inflammatory drug, and hyaluronic acid is a man-made substance that mimics naturally occuring joint fluid.
Investigators in both studies examined data from the Osteoarthritis Initiative, a long-term observational study of patients with knee osteoarthritis. They used either magnetic resonance imaging or X-rays to observe patients’ joints over time.
In a two-year MRI investigation from the University of California, San Francisco, corticosteroid knee injections were linked to overall progression of osteoarthritis in the knee, whereas hyaluronic acid knee injections were not significantly associated with progression.
In addition, when compared to a control group, the group who received hyaluronic injections showed a decreased progression of osteoarthritic bone marrow lesions, investigators reported.
X-rays show damage
The other study compared signs of osteoarthritis that were similar at baseline among patients with and without the two types of injections. In X-rays, knee joint damage was worse after two years in patients who received the corticosteroid injections when compared to patients who received hyaluronic acid injections or no treatment at all, researchers from the Chicago Medical School of Rosalind Franklin University of Medicine and Science reported.
Both sets of researchers recommend using steroid injections for knee osteoarthritis with more caution. Meanwhile, they believe it is important to further explore hyaluronic acid injections for use in treating arthritic knee pain.
The findings were presented at the annual meeting of the Radiological Society of North America in 2022.