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Repeated Corticosteroids Injections Not Beneficial for Knee OA Longterm

June 2, 2017
A comparison of multiple injections of intra-articular triamcinolone versus saline on long-term effects of pain and cartilage volume, corticosteroids offered no significant clinical improvement over placebo, for most patients.

Interviews with Jeffrey B. Driban, PhD, Gordon D. Ko, MD, PhD, CCFP (EM), FRCPC

Repeated injections of intra-articular triamcinolone in patients with knee osteoarthritis (OA) failed to provide improve pain relief over a 2-year period compared with patients who received repeated injections of saline, according to study results published in the Journal of the American Medical Association.1

Researchers also found significantly greater cartilage volume loss in OA patients who received the corticosteroid injections, although they concluded the differences, while statistically significant, were probably not clinically useful.

The study outcomes put into perspective and solidified some of what clinicians already knew, said study coauthor Jeffrey B. Driban, PhD, a researcher in rheumatology at Tufts Medical Center and assistant professor of medicine at Tufts University School of Medicine in Boston, Massachusetts.

"We've known for a while that cortisone injections for knee OA may offer short-term pain relief for a few weeks. What we were testing here is whether getting repeated injections every 3 months would offer prolonged pain relief," Dr. Driban told Practical Pain Management.

Multiple corticosteroid injections not beneficial for most people with knee osteoarthritis.

Assessing Cortisteroid Injections Against Placebo

The researchers randomly assigned 140 patients (75 women, 65 men) with knee OA to the treatment group or the saline group. The mean age of patients was 58 years. In all, 119 (85%) completed the 2-year study.1

Patients were eligible for the study if they had at least 2 or higher but at 8 or less on the weight-bearing part of the WOMAC pain subscale (range 0-12); radiographic severity had to be Kellgren-Lawrence grad of 2 or 3. For 48 hours prior to pain assessment, participants discontinued any analgesic medication.1

The injection of triamcinolone was 40 mg/mL. The comparator was 1 mL of 0.9% sodium chloride. Neither was mixed with anesthesia. Prior to the injection, synovial fluid equal to or less than 10 mL was aspirated from the knee.1

Participating men and women underwent functional magnetic resonance Imaging (fMRI) at the start of the study to establish a baseline scan, and again at 1 and 2 years, to measure any changes in cartilage volume.1

Comparing Changes in Pain Relief, Cartilage Volume

The decrease in knee pain scores were -1.2 in the active group and -1.9 in the placebo group. The between-group mean difference was -0.6 (95% C, -1.6 to 0.3), wrote the authors.

While an overall decrease in pain was not substantially different, the researchers acknowledged a study limitation—they did not measure pain relief in the first 4 weeks after an injection when pain relief was expected to be the greatest. The intra-articular triamcinolone injections, however, resulted in significantly greater cartilage loss. The mean change in index compartment cartilage thickness was -0.21 mm versus -0.10 mm for the active vs. placebo groups, respectively (P = 0.01).1

"The intervention group had more cartilage loss than the placebo group, but we don’t think it was clinically significant," Dr. Driban said. The saline group had 3 treatment-related adverse events compared to 5 in the active group, including injection site pain, cellulitis, and facial flushing.1

Consider Multiple Injections Individually

"What this study draws attention to is if you just do [injections] repeatedly, it is not good for you," Gordon D. Ko, MD, PhD, CCFP (EM), FRCPC, told Practical Pain Management.

Even so, experts agree that there is a role for the injections. "We use steroids on and off in our practice," said Dr. Ko, assistant professor of physical medicine and rehabilitation at the University of Toronto. "It makes sense to take the fluid out [first]," he said, "You want to get the fluid out and put the steroid in to cool it down."

Deciding what therapy is best for which patients is a balancing act, said Dr. Ko. "You look at each individual. If it’s a 78-year-old individual with limited funds but [steroid] injections every 3 months will keep them from [needing] a wheelchair, fine," he said.

"If the patient is a [baby] boomer and wants to keep running, or when he hits his 70s or 80s he wants to still be able to do his favorite sport, whether golfing or hiking, you are not going to be using cortisone [injections] repeatedly," Dr. Ko said.

In those cases, the clinician should look to more promising treatments, Dr. Ko said. As an example, a study published in the American Journal of Sports Medicine reported that 78% of patients who received 3 injections of plasma rich protein (PRP) a week apart had a 78% improvement in WOMAC scores compared to just a 7% improvement in the saline group,he said.

However, PRP is expensive, with estimates at between  $500 and $1,000 an injection,3 and investigational, said Dr. Ko, "We have to find a way to make PRP more affordable."  As for stem cells, he said, ''I'd like to see more data."

Perspective on Treatment of OA in Clinical Practice

Injecting a corticosteroid ''is beneficial in the short term," Dr. Driban said. "It offers pain relief for the first few weeks after the injection."

The main unanswered issue has to do with the greater cartilage loss in the intervention group, Dr. Driban said, "We may continue to follow these patients out further to better understand what happens in the longer term."

While other experts consider approaches, such as plasma rich protein and stem cells, as promising therapies to address knee OA pain, Dr. Driban said that any recommendations for use of these treatments are premature—the need more evidence before any clinical value ought to be considered.

Meanwhile, he said, those with knee OA pain should consider exercise, diet to reduce excess weight if applicable, and inclusion of analgesics as part of their treatment plan.

The doctors interviewed for this article disclosed that they don't have any relevant conflicts of interest to report.

Last updated on: June 2, 2017
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