Anatomy, pathophysiology and classification of posterior tibial tendon dysfunction

Objective: Adult acquired flatfoot deformity is generally associated with a collapsing medial longitudinal arch and a progressive loss of strength of the posterior tibial tendon (PTT). This condition is commonly associated with PTT dysfunction or rupture, which can have an arthritic or a traumatic etiology. Several causes have been proposed to explain the clinical evidence of tendon degeneration observed at the time of surgery including trauma, anatomical, mechanical, inflammatory and ischemic factors. Materials and methods: In this review, we analyzed anatomy, pathophysiology and existing classifications of posterior tibial tendon dysfunction. Results: Anatomical features, and in particular vascularization, expose PTT to major degenerative disorders until rupture. A literature overview showed that a low blood supply of the gliding part of the tendon is linked to a dysfunction and/or a rupture of the PTT in the region located behind the medial malleolus. Conclusions: PTT low blood supply causes a dysfunction resulting in an abnormal loading of the foot's medial structures. This may be the reason why PTT dysfunction leads to an acquired flatfoot deformity. Conversely, flatfoot deformity may be a predisposing factor for the onset of PTT dysfunction.