BACKGROUND Achilles tendinopathy-pain in the Achilles tendon-is a common and often long-lasting condition that limits physical activity and performance, and also affects work capacity and quality of life. The pain is localized either to the mid- portion of the tendon or at its insertion into the calcaneus. Although individually tailored exercise is the first-line treatment, symptoms persist in many patients, highlighting the need for adjunctive therapies.
AIM This interdisciplinary and innovative research project aims to evaluate the effect of shockwave therapy in Achilles tendinopathy, both in cases where the pain is located in the mid-portion of the tendon and where it is situated at the tendon's insertion. In addition to assessing effects on pain and function, the study will examine the impact on calcifications, neovascularization (evaluated via Doppler ultrasound), and-uniquely-systemic immunological effects, with a focus on NK cells in the blood, an area that remains largely unexplored. METHOD This is a randomized controlled trial (RCT) with four arms, including 200 patients divided into two groups based on pain location. Half of the participants will receive adjunctive shockwave therapy in six sessions, in addition to exercise following the protocol by Silbernagel et al. The primary outcome measure is self-reported pain assessed using the Numeric Rating Scale (NRS) 0-10 at 12 months.
Secondary outcomes include function, assessed through patient-reported outcomes (Victorian Institute of Sport Assessment-Achilles Swedish version, VISA-AS), calf muscle strength and endurance, and jumping ability using a validated test battery. Neovascularization and tendon cross-sectional area will be evaluated using ultrasound/Doppler.
In a sub-cohort, immune cell composition in blood will be analyzed using flow cytometry before and after treatment. For patients undergoing surgery, tissue samples will also be collected for cellular composition analysis.
SIGNIFICANCE This project has the potential to improve treatment strategies, reduce the need for surgery, and generate entirely new knowledge about the relationship between local tissue pathology and systemic immune responses.