A new study in the Journal of the American Medical Association questions the benefits of a widely accepted injection (meant to reduce inflammation) by looking at 140 people with arthritis of the knee.
They were randomly assigned to get either steroid shots or placebo shots of saline instead, every 12 weeks, for two years. The providers administering the shots didn't even know whether the shot contained steroids or saline.
To evaluate effects on the knee cartilage, researchers gave participants a yearly MRI and checked them every three months using an arthritis index. After two years, those who received steroid injections in the knee had twice as much cartilage loss as those who received saline injections.
The steroid group also had a higher arthritis index, a score measuring the stages of joint disease, than the saline group. No difference was found in the amount of pain reported by either group. Researchers said the results suggest that while steroid injections, in theory, reduce inflammation, other purported benefits were not observed.
The investigators say this suggests two things: first, that inflammation may not play as big a role in the progression of arthritis as we thought, and second, that placebo knee injections may have clinical benefit.