Results of a 2-year clinical trial suggest that corticosteroid injections in the knee joints are safe but not effective, according to findings presented at the 2015 annual meeting of the American College of Rheumatology/ARHP.
Synovitis is common among patients with osteoarthritis (OA) and steroid injections are often used to help manage symptoms. Tim McAlindon, MD, MPH, chief of the Division of Rheumatology at Tufts Medical Center in Boston, and other researchers from Tufts Medical Center and Boston University conducted their study to test the use of steroid injections to treat 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,” the investigators said. “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 was funded by the National Institutes of Health and included 140 participants—average age 58 years and average body mass index (BMI) 31.2 kg/m2—who were diagnosed with OA and had synovitis detected by ultrasound. Participants were split into 2 groups: the first received steroid triamcinolone hexacetonide injections every 12 weeks over 2 years, and the second received placebo saline injections at the same interval.
Researchers used the Western Ontario and McMaster Universities Arthritis Index (WOMAC) to measure participants’ pain and function, annual MRIs and Cartilage Damage Index to measure cartilage damage, and annual dual energy x-ray absorptiometry scans to measure bone density.
The researchers found that pain and function improved in both groups, but there was no difference in their WOMAC scores. There was also no significant difference between the 2 groups when the participants completed a walking test and rise from a seated position in a chair.
The group that received steroid injections had a greater loss of cartilage, according to the Cartilage Damage Index scores, and the placebo group had more cartilage fraying.
“This study did not find any long-term benefit of intra-articular corticosteroids for either patient-reported outcomes for progression of structural damage, nor did the injections cause more damage in the 2 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,” stated Dr McAlindon.
“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 mg), and we might have seen greater effects with a higher-strength formulation.”
The researchers recommend that additional research be conducted to examine targeted anti-inflammatory interventions and the potential opportunities when using a higher dose.
Summary and Clinical Applicability
Injections of corticosteroids into the knee joint appear to be safe, but not effective, in improving patient-reported outcomes or slowing the progression of structural damage to the knee.
American College of Rheumatology. Abstract 897. 2-Year Clinical Trial Shows Joint Injections with Steroids Are Ineffective in Reducing Progression of Knee Osteoarthritis. Presented at: ACR/ARHP Annual Meeting, November 6-11, 2015; San Francisco, CA. Abstract 897.