Steroid injections used to treat arthritis in the knee may actually make the condition worse, a study suggests.
Researchers from the University of California, San Francisco (UCSF) and Chicago Medical School across two studies gathered data from hundreds of osteoarthritis patients to gauge how their condition would react to the shots.
Between both studies, 94 patients who received corticosteroids – anti-inflammatory drugs used to treat a variety of medical conditions – saw their condition deteriorate.
Those who received hyaluronic acid injections, a naturally produced substance that lubricates the joints, saw the progress of their condition slow.
Previous research suggests corticosteroids may damage cartilage in a joint and make it more susceptible to wearing down, leaving patients needing hip or knee replacements.
More than 32.5million adults in the US have knee arthritis, with approximately 80 per cent of adults over 55 years old having evidence of the condition.
More than one in ten of these patients opt to get corticosteroid or hyaluronic acid injections to relieve their pain.
The above shows the knee joint of a patient with arthritis (left), with the arrows indicating where cartilage has been worn away. The other (right) shows a patient who does not have arthritis
In the first study — to be presented Monday at the Radiological Society of North America — researchers in California analyzed two years of data for 210 patients with osteoarthritis in the knees.
More than half the group — 140 people — did not get the injections during this time.
Among the rest, 44 were injected with corticosteroids, while 26 were injected with hyaluronic acid.
Corticosteroids reduce the activity of white blood cells and stop the immune system from causing the painful inflammation.
Hyaluronic acid is naturally found in the fluid of a person’s eyes and joints.
It acts as lubrication for the joints, helping mitigate pain when they are used.
All were matched by age, sex, body mass index, pain and physical activity scores and severity of disease.
MRIs were done two years before treatment, at the time of treatment and two years later, with scans scored for arthritis progression.
Analysis showed those who got corticosteroid injections had significantly faster arthritis progression compared to the other groups.
The hyaluronic acid treatment group, however, showed a decreased progression of osteoarthritis compared to those who got no treatment.
Dr Upasana Upadhyay Bharadwaj, a radiologist at UCSF who led the study, said: ‘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.
‘Hyaluronic acid, on the other hand, may slow down progression of knee osteoarthritis and alleviate long term effects while offering symptomatic relief.’
He added that this was the first study directly comparing the two treatments using these types of MRI scans.
In the second study from researchers in Chicago, data was analyzed on 150 patients who were monitored for a 36-month period.
The group was evenly split between people who got no injections, hyaluronic injections and corticosteroid injections. They were also matched by sex, body mass index and X-ray findings.
Patients underwent an X-ray when injections were administered and two years later, with each scored for progression of the disease.
Those who got the corticosteroid injections had significantly more osteoporosis progression two years later, results showed.
But those who got hyaluronic acid injections or no treatment at all did not have as rapid deterioration.
Azard Darbandi, a medical student at Chicago who led the research, said: ‘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.
‘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.’
Patients may opt to get corticosteroid injections in the knee to provide short-term pain relief against arthritis.
But over the longer term these studies suggest that they can actually lead to more rapid deterioration in the joints, prompting more pain.
Participants were recruited from the Osteoarthritis Initiative which is an observational study of nearly 5,000 patients. It is now in its 14th year.