The Achilles tendon enthesis as an “organ”

an updated concept of Achilles insertional tendinopathy

Abstract

Enthesis (osteotendinous insertion sites) are places of concentration of stress and energy dissipation between tendons and bone. Consequently, they are subject to a higher incidence of overuse injuries (enthesopathy). In this review, we focus on the structure-function correlations of enthesis and special attention is given to the mechanical factors that influence the relation between enthesis and the exercise. The application of the concept of “enthesis organ” is related to a set of structures adjacent to the enthesis itself, which act together with the function of dissipating energy is fundamental to understand the insertional tendinopathies of the Achilles tendon. There is a special focus on the degenerative and noninflammatory nature of insertional tendinopathy.