Steroid injections for osteoarthritis is like
Snapchat. Everyone seems to be doing it, and no one is quite sure why.
But a major blow to that most common – and lucrative – of in-office procedures was
dealt this week, in the form of this trial, appearing in the Journal of the American Medical
Association. Far from the shot in the arm – knee – the
good makers of triamcinolone injection needed, this trial shows that the steroid shot may
be no better than saline, and actually might be a bit worse.
By way of background, the use of steroid injections for osteoarthritis has always been a bit controversial.
The most recent Cochrane review of the literature on the subject, conducted in 2015, found a
modest benefit to the practice, but cautioned: “We graded the quality of the evidence as
low for all of our ﬁndings, which means that we have little conﬁdence in these results”.
Their forest plot, pictured here, shows the results of 25 trials.
The effects are all over the place. And most trials were seriously underpowered.
The current study may be the best of the bunch. Researchers randomized 140 patients with knee
osteoarthritis to steroid or saline injection every 12 weeks for 2 years. At each visit,
they asked about pain and function. At baseline, 1 year, and 2 years in, they also got a knee
MRI to examine the cartilage. These patients were well-selected. They not
only had osteoarthritis but evidence of synovitis on ultrasound. In other words, if anyone is
going to respond to steroids, this is the group.
And you know where this is going. There was no difference in knee pain at any time point
across the two groups, though pain did decrease a bit in all patients. Thank you, placebo
effect. No changes in function, stiffness or walk time either.
In fact the only thing that changed significantly between the groups was the change in cartilage
thickness. Those who got steroid lost 0.16mm more cartilage than those who got saline,
a statistically significant, if clinically indeterminate result.
Do steroids still have a role? I spoke with an Orthopedic Surgeon who pointed out that
steroids should really only be used for flares of osteoarthritis, not as a long-term treatment
strategy. He also mentioned that the pain relief is real, but short-lived, and may not
have been captured by the every-three-month pain surveys the researchers conducted.
But with this trial showing potential cartilage loss, and somewhat shoddy older data, it’s
hard to justify the procedure without citing anecdotal evidence. Hyaluronic acid injections,
look out. You might be the next to feel the pinch.