Achilles Tendinopathy

The essential lesion of Achilles tendinopathy (AT) is a failed healing response, a complex multifaceted pathology of the tendon, characterized by pain, swelling, loss of function, and reduced exercise tolerance. The most common overuse tendinopathies involve rotator cuff tendon, medial and lateral elbow epicondyles, patellar tendon, gluteal tendons, and the Achilles tendon. Microscopically, tendinopathy is characterized by disorganization of collagen fibers, increase in microvasculature and sensory nerve innervation, dysregulated extracellular matrix homeostasis, increased immune cells and inflammatory mediators, and enhanced cellular apoptosis. The diagnosis is clinical, while MRI or US imaging can be useful in differential diagnosis. Conservative management, with different exercise and loading programs and/or injection and physical therapy, open surgery, or minimally invasive techniques are available. However, their effectiveness remains ambiguous, and a clear consensus has still not been reached. Surgery is indicated after 6 months of appropriate nonoperative management. Future research is needed, focusing on the key functional pathways implicated in the clinical condition, and to improve rehabilitation protocols.