US researchers are questioning the use of corticosteroid injections for pain relief of osteoarthritis in the knee.
In two independent studies, the impact of a single intraarticular (inside the joint) corticosteroid injection in osteoarthritic patients was followed up after two years.
Before and after imaging showed that the disease had significantly progressed – compared with the knees of participants injected with hyaluronic acid and a control group who received no injection.
Further findings
According to a report from the Radiological Society of North America (RSNA), statistical analysis showed that corticosteroid knee injections were significantly associated with the overall progression of osteoarthritis in the knee, specifically in the lateral meniscus, lateral cartilage and medial cartilage.
Hyaluronic acid knee injections were not significantly associated with the progression of osteoarthritis in the knee.
In fact, one of the studies found that hyaluronic injections “showed a decreased progression of knee arthritis, specifically in bone marrow lesions”, when compared with the control group.
The results of the studies were presented this week at the RSNA’s annual meeting.
What the researchers say
Dr Upasana Upadhyay Bharadwaj, a research fellow in the Department of Radiology at University of California, San Francisco, said:
“This is the first direct comparison of corticosteroid and hyaluronic acid injections using the semi-quantitative, whole organ assessment of the knee with MRI.
“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.”
Dr Bharadwaj added: “Hyaluronic acid, on the other hand, may slow down progression of knee osteoarthritis and alleviate long-term effects while offering symptomatic relief.”
The second study was by the Chicago Medical School of Rosalind Franklin University of Medicine and Science.
What is hyaluronic acid?
Hyaluronic acid (also known as hyaluronan) is produced in the body as a lubricant.
Hyaluronic acid (HA) oral supplements are said to be a helpful treatment for osteoarthritis.
Taking 80–200 mg daily for at least two months has been shown to significantly reduce knee pain in people with OA, especially those between the ages of 40 and 70 years old.
A 2018 study suggests that a combination of oral hyaluronic acid supplements with injections might prolong pain-relief and extend the time between injections.
The findings aren’t a great surprise
The Mayo Clinic advises that, in general, “you shouldn’t get cortisone injections more often than every six weeks and usually not more than three or four times a year”.
The main concern is that repeated use of corticosteroids destroys the cartilage in the joint, which effectively progresses the disease.
Potential side effects of cortisone shots increase with larger doses and repeated use. These can include death of nearby bone, nerve damage, and tendon weakening or rupture.
Corticosteroids and OA in Australia
According to a Cochrane review posted by the RACGP, osteoarthritis affects at least 1.2 million Australians.
It is the leading cause of pain and disability in the community, particularly affecting women, and the seventh most commonly managed condition in general practice.
Goals for managing OA are to reduce pain, improve and maintain joint mobility, and limit functional impairment.
Intra-articular (IA) treatments for knee osteoarthritis are often promoted as an option when oral medication fails, and are seen as a last-resort before surgery.
Hyaluronic acid is longer lasting than IA corticosteroids but “more expensive and must be given more often in the initial course”.
