Summary
In a 192-person randomised trial, high-volume injections with or without corticosteroid did not improve Achilles pain or disability over a sham injection at 12 months. The corticosteroid injection showed a small short-term benefit, followed by worse outcomes than the injection without steroid at 26 weeks.
A randomised trial published in The BMJ found that high-volume injections, with or without corticosteroid, did not improve pain or disability compared with a sham injection one year after treatment for midportion Achilles tendinopathy. The trial also found a small improvement at six weeks with the corticosteroid injection, but worse outcomes than the injection without steroid at 26 weeks.
The Inject trial randomly assigned 192 adults to one of three groups: sham injection (64 participants), high-volume injection without corticosteroid (63), or high-volume injection with corticosteroid (65). Participants in all groups also received the same progressive exercise programme, education and advice on modifying activity.
How the trial compared the injections
Participants were at least 18 years old and had symptoms for three months or longer, a clinical and ultrasound diagnosis, and a VISA-A score below 75. The VISA-A questionnaire measures Achilles-related pain and disability on a 0–100 scale, with higher scores indicating fewer symptoms. The study took place at one radiology clinic in Melbourne, Australia.
The high-volume injections delivered 50 mL of fluid between the Achilles tendon and Kager’s fat pad under ultrasound guidance. In the corticosteroid group, the first 10 mL contained 0.5% bupivacaine and 25 mg hydrocortisone, followed by 40 mL of saline. The other high-volume injection used the same approach without hydrocortisone. The sham involved 2–3 mL of bupivacaine injected at least 10 mm away from the tendon-fat-pad interface.
The primary outcome was VISA-A at 52 weeks. Data were available for 181 participants, or 94% of those randomised.
Benefits did not persist to the one-year assessment
At 52 weeks, neither high-volume injection showed a clear advantage over sham. The difference for the corticosteroid injection was -3.5 points (98.33% confidence interval -12.0 to 5.0), a result favouring sham; for the injection without corticosteroid it was 4.0 points (-4.2 to 12.3), favouring the injection. The trial had set 10 points as the target difference for a meaningful comparison.
At six weeks, the corticosteroid injection had a 9.2-point advantage over sham (98.33% confidence interval 1.8 to 16.9). The point estimate was below the trial’s 10-point target. At 26 weeks, outcomes favoured the injection without corticosteroid over the one with it by 8.6 points (-16.4 to -0.7). The authors said the overall clinical findings do not support routine use of high-volume injections with corticosteroid for this condition.
The economic analysis, conducted from a societal perspective, estimated that the corticosteroid injection had more than a 90% probability of being cost effective compared with sham at willingness-to-pay thresholds of AUS$50,000 and AUS$100,000. The groups had similar quality-adjusted life-years, with only a very small estimated health advantage for the corticosteroid group. The authors noted that this economic result should be interpreted cautiously alongside the clinical findings.
No Achilles tendon ruptures occurred during the 12-month trial. Six participants had serious adverse events, none considered related to the trial; one non-serious event, injection-site pain, was attributed to an injection. The study recruited mainly through social media and was conducted at a single clinic, so its participants may not represent everyone seeking care for Achilles tendinopathy.