Corticosteroid injections ease the pain of tennis elbow short term but may worsen it long term, according to a meta-analysis.
The injections significantly cut pain scores over the first four weeks with a standardized mean difference of 1.44 compared with no intervention (*P*<0.0001), Bill Vicenzino, PhD, of the University of Queensland in St. Lucia, Australia, and colleagues reported online in *The Lancet*.
But by six months, the effect had reversed to significantly favor no treatment (standardized mean difference -0.40, *P*<0.003). And at 12 months, no treatment still looked better than the injections (standardized mean difference -0.31, *P*=0.05).
– corticosteroid injections ease the pain of tennis elbow short term but may worsen it long term.
– this study concluded that there is insufficient evidence for the efficacy of corticosteroid injections for treatment of tendinopathies of the Achilles and kneecap.
– other tendinopathies showed mixed results.
There is insufficient evidence for the efficacy of corticosteroid injection in tendinopathies of the Achilles and kneecap, and the rarity of acute tendon rupture with corticosteroid injections — less than 1% in the meta-analysis — was reassuring, the editorialists noted.
Other injections, such as such as plasma-rich protein, prolotherapy, or sodium hyaluronate injections, should still be considered experimental with no evidence that any are a magic bullet for tendinopathy, they cautioned.
Of the 2,672 patients in these trials, 1,171 had tennis elbow. For them, corticosteroid injections were consistently better in the primary outcome of protocol-defined pain score at one month with large effect sizes compared with no intervention, nonsteroidal anti-inflammatory drugs (NSAIDs), physiotherapy, and orthotic devices.
At six months, though, tennis elbow showed significantly poorer reductions in pain compared with no intervention, NSAIDs, physiotherapy, and platelet-rich plasma injections. The same pattern was seen at 12 months with the exception of no difference between NSAIDS and corticosteroids.
Notably, repeated corticosteroid injections — ranging from three to six over 18 months — actually yielded poorer long-term pain results than just one injection.
For rotator cuff tendinopathy, the 10 trials showed conflicting short-term results for corticosteroid injections ranging from a medium effect compared with placebo to no difference compared with NSAIDs or physiotherapy. Intermediate and long-term results showed no differences among the treatments.
For medial epicondylalgia (also known as golfer’s elbow), the one study available showed no benefit of corticosteroid injection even in the short term.
For tendinopathies of the leg, the one trial evaluable indicated a large short-term pain reduction with corticosteroid injection, but more for patellar than Achilles tendons.
Given these findings, the researchers cautioned in the paper that “response to injection should not be generalized because of variation in effect between sites of tendinopathy.”
Adverse events seen with corticosteroid injection included atrophy (9%), pain (8%), depigmentation (less than 1%), and one case of tendon rupture of the Achilles tendon (less than 1%).
Among the other types of injections, the researchers found:
– The sclerosing agent polidocanol (Asclera, also known as lauromacrogol) improved patellar tendinopathy but not Achilles tendinopathy or tennis elbow.
– Platelet-rich plasma yielded mixed results with no short- or intermediate-term pain reductions in one study for Achilles tendinopathy but a large effect at intermediate and long term in a second study.
– The collagen-building substance sodium hyaluronate substantially improved tennis elbow at all time points compared with placebo in one study but was no better than electrotherapy for rotator cuff tendinopathy in another.
– Injections of an irritant to stimulate the body’s repair mechanisms (prolotherapy) held no reduction in pain short term but a big effect at six months for tennis elbow in one study and no difference at any time point for Achilles tendinopathy compared with the combination with eccentric exercise in a second study.
– Botulinum toxin (Botox) showed a big pain reduction short term for chronic tennis elbow compared with placebo in one trial.
The study received partial support from the National Health and Medical Research Council of Australia.
*Primary source: *The Lancet
Coombes BK, et al “Efficacy and safety of corticosteroid injections and other injections for management of tendinopathy: a systematic review of randomised controlled trials” *Lancet* 2010
Dr. Tucker recommends a trial course of warm laser and/or Deep Muscle Stimulation (DMS) for such injuries prior to cortisone injections. A reasonable trial course may include 6-7 sessions. If the pain improves the warm laser and/or DMS can be continued. If the trial course did not help, it is reasonable to try another course of treatment.