Recognizing that there is inflammation in osteoarthritic joints and that the inflammation may damage and cause progression, along with the knowledge that steroids can suppress inflammation, researchers hypothesized that corticosteroids may have disease-modifying effects, notes Dr. McAlindon.
The Study
Enrollment began in 2013 at Tufts Medical Center and the study was completed by Jan. 1, 2015. Recruited patients had an average age of 58, met ACR criteria for symptomatic knee OA and were graded 2 or 3 on the Kellgren-Lawrence scale.
The double-blind, randomized trial involved 140 patients who were given either triamcinolone or saline intra-articular injections every 12 weeks over two years. Synovial fluid was aspirated before injection if present, according to Dr. McAlindon.
During study visits, patients underwent examinations of the treated knee and monitoring of physical function, blood pressure, pain, medication and adverse events. Ultrasound was used to determine degree of inflammation, and magnetic resonance imaging scans conducted at baseline, 12 and 24 months measured quantitative cartilage volume.
Two primary outcomes were change in knee cartilage volume in the index compartment—measured by thickness—and change in pain. The latter was assessed with WOMAC pain subscale patient questionnaires.
Dr. McAlindon says this study is only the second one to measure long-term use, and it is the first to use MRIs to quantitatively measure cartilage and soft-tissue structures. Unlike radiography, MRIs allow direct visualization of those structures and cartilage and is much more precise than X-rays.
“Radiography does not image cartilage directly and is insensitive to change, so it may not have detected the small changes in cartilage loss measured on the MRIs in this study,” states the article.
Study results revealed that patients treated with triamcinolone injections had a greater rate of cartilage loss in the index compartment compared with patients given placebo (-0.21 vs. -0.10 mm, respectively). Knee pain decreased somewhat, but not significantly more in one group than the other (-1.2 units in the triamcinolone vs. -1.9 in the saline group).
“Everybody loses some cartilage volume with age,” Dr. McAlindon says, commenting on the results. “That’s to be expected. Of course, the hope of this study was that this may actually be beneficial, but in fact we found no difference between the groups for all the outcomes except cartilage volume, where, in fact, the loss was increased.”
The authors concluded that the findings do not support “this treatment for patients with symptomatic knee osteoarthritis.”
Because there is potential for the study findings to cause concern, Dr. McAlindon says that it’s important to put them in context.
What This Means
“The magnitude of loss was not all that great,” says Dr. McAlindon. “Clearly, in this particular study, the two years didn’t translate into a clinically important difference between the two groups.”
