Background of the study - Overuse injury of the Achilles tendon is a common entity in athletes. Especially middle aged athletes are at risk. Elite running athletes have a lifetime risk of sustaining an Achilles tendon injury of 52%. At the moment the usual treatment for chronic midportion Achilles tendinopathy is an excentric exercise program. In most cases this gives great results, however there is a significant group of patients in which the exercise program is not sufficient. Three United Kingdom-based case series evaluated the efficacy of High-Volume Image-Guided Injections (HVIGI's) in chronic midportion Achilles tendinopathy. They all showed promising results. However none of these studies used a comparative group. There is consequently a lack of high-quality studies in this field and therefore the investigators cannot recommend this treatment yet for this indication.~Objective of the study - To investigate the efficacy of a high-volume image guided injection (HVIGI) in chronic midportion Achilles tendinopathy.~Hypothesis - The average VISA-A score is higher in the patient group treated with a progressive exercise program in combination with a high volume image guided injection in comparison with the group treated with low volume injection as a control group in combination with a progressive exercise program.~Study design - A double-blind, randomized, placebo-controlled clinical trial. Randomization and stratification (based on activity level using the Ankle Activity Score) will be performed using a computer-generated model. Measurements will be performed at baseline, 2, 6, 12 and 24 weeks post injection. At every time point both the primary and secondary outcome measurements will be collected. The painDETECT and the Pain Coping Inventory questionnaires will be derived at baseline and 24 week post injection.~Study population - In total, 80 patients with clinically diagnosed chronic midportion Achilles tendinopathy will be included in this study.
Overuse injury of the Achilles tendon is a common entity in athletes. Currently, the usual treatment for chronic midportion Achilles tendinopathy is an eccentric exercise program. In most cases this gives satisfactory results, however there is a significant group of patients in which the exercise program is not sufficient. Prior to our study, three United Kingdom based studies have investigated the efficacy of High-Volume Image-Guided Injections (HVIGI's) in chronic midportion Achilles tendinopathy. They all showed promising results. However none of these studies had an adequate control group. This double-blind, placebo-controlled, randomized clinical trial will investigate the value of a High-Volume Image-Guided Injection in chronic midportion Achilles tendinopathy.