knee injectionInjections of corticosteroids in the knee joints appear to be safe, but not effective, according to the findings of a two-year clinical trial presented at the American College of Rheumatology Annual Meeting in San Francisco.
Osteoarthritis, sometimes called degenerative joint disease, is a slowly progressive disease in which joint cartilage breaks down. Normally, cartilage on the ends of bones allows smooth, pain-free joint movements. In OA, cartilage becomes thin and irregular, resulting in symptoms of joint pain and stiffness. Grinding or cracking sensations may occur. Joints that are under high stress due to repeated activity or weight bearing are most susceptible to OA. The hips, knees, hands and spine are commonly affected. OA becomes more common with aging.
Inflammation in the lining of the knee joint (called synovitis) is common among people with knee OA, and many physicians use steroid injections in the knee to help manage symptoms. Researchers from Tufts Medical Center and Boston University recently looked at the use of steroid injections to address synovitis in the knee.
“Recent insights into the role of inflammation on OA raise the possibility that suppressing those processes may reduce progression of structural damage in the joint,” says lead investigator in the study, Tim McAlindon MD MPH; chief, Division of Rheumatology; Natalie V. Zucker and Milton O. Zucker Chair in Rheumatology, Tufts Medical Center In Boston, Mass. “Intra-articular corticosteroids are already in widespread use in the treatment of knee OA, but have never been specifically tested for this purpose. However, there are also theoretical concerns that corticosteroids may have deleterious effects on articular cartilage.”
The study, followed 140 participants who had been diagnosed with OA and had signs of synovitis as seen by ultrasound. The participants were predominantly white women with an average age of 58 and an average BMI of 31.2. The participants were split into two groups, and neither the participants nor the researchers knew who was in each group. The first group received injections of the steroid triamcinolone hexacetonide every 12 weeks over the course of two years (eight injections total), while the second group received placebo injections of saline at the same intervals.
Dr. McAlindon’s team assessed the participants’ pain and function through the Western Ontario and McMaster Universities Arthritis Index (called WOMAC) at each visit, cartilage damage via annual MRIs and the Cartilage Damage Index, and bone density using annual dual energy X-ray, or DXA, scans. Throughout the course of the study, as expected, pain and function improved in both groups, but there was no difference between the groups in their WOMAC scores. The researchers also saw few differences in the results of the two groups when asked to complete a test that required them to rise from a seated position in a chair as well as walking test.
There were only differences noted in the Cartilage Damage Index scores and in the fraying of cartilage. The group that received the steroid injections had a greater loss of cartilage based on the Cartilage Damage Index scores, and the group that received placebo had more fraying of the cartilage.
“This study did not find any long-term benefit of intra-articular corticosteroids for either patient-reported outcomes or for progression of structural damage, nor did the injections cause more damage in the two years they were studied. There did appear to be slightly more cartilage loss in the treated arm, but the difference was small in magnitude and did not appear to be clinically meaningful, explains Dr. McAlindon, who also notes there were some limitations in the study.
“We did not set out to capture the (already known) short-term symptom benefits of intra-articular corticosteroid injections, so this study does exclude their use as an acute treatment modality. Additionally, the dose was fairly small (40 mgs), and we might have seen greater effects with a higher strength formulation.” To that end, Dr. McAlindon recommends further studies to evaluate targeted anti-inflammatory interventions, including possibly using a higher dose.

Source Newsroom: American College of Rheumatology (ACR)
Citations
ACR Annual Meeting, Nov-2015