Effectiveness of a high volume injection as treatment for chronic Achilles tendinopathy: randomised controlled trial

OBJECTIVE: To study whether a high volume injection without corticosteroids improves clinical outcome in addition to usual care for adults with chronic midportion Achilles tendinopathy. DESIGN: Patient and assessor blinded, placebo controlled randomised clinical trial. SETTING: Sports medicine department of a large district general hospital, the Netherlands. PARTICIPANTS: 80 adults (aged 18-70 years) with clinically diagnosed chronic midportion Achilles tendinopathy and neovascularisation on ultrasonography. 39 were randomised to a high volume injection without corticosteroids and 41 to placebo. INTERVENTIONS: Participants were instructed to perform an exercise programme for 24 weeks (usual care) combined with one 50 mL high volume injection of saline and lidocaine (intervention group) or one 2 mL placebo injection of saline and lidocaine (placebo group) at baseline. MAIN OUTCOME MEASURES: Primary outcome was pain and function assessed using the validated Victorian Institute of Sports Assessment-Achilles (VISA-A) questionnaire at 24 weeks (analysed using a generalised estimation equations model). Secondary outcomes were patient satisfaction, return to sport, degree of ultrasonographic Doppler flow, visual analogue scale on 10 hop test, power and flexibility of the gastrocnemius and soleus muscles, pain detect questionnaire for neuropathic pain, and pain coping inventory. Participants were evaluated at baseline and at 2, 6, 12, and 24 weeks. RESULTS: Only one participant (1%) was lost to follow-up. The estimated mean VISA-A score improved significantly, from 40.4 (95% confidence interval 32.0 to 48.7) at baseline to 59.1 (50.4 to 67.8) at 24 weeks in the high volume injection group and from 36.9 (27.1 to 46.8) to 58.5 (47.9 to 69.1) in the placebo group. The VISA-A score over time did not differ between the groups (adjusted between group difference at 24 weeks 0.5 points, 95% confidence interval −17.8 to 18.8). No significant between group differences were found for patient satisfaction (21/37 (57%) v 19/39 (49%) patients, P=0.50) and return to desired sport (15/29 (52%) v 19/31 (61%) patients active in sports, P=0.65) at 24 weeks. None of the other secondary outcomes differed between the two groups. CONCLUSIONS: A high volume injection without corticosteroids in addition to usual care is not effective for symptom reduction in patients with chronic midportion Achilles tendinopathy. On the basis of our findings, we cannot recommend the use of a high volume injection in this patient group. TRIAL REGISTRATION: ClinicalTrials.gov NCT02996409