Posterior tibial tendon dysfunction as a cause of acquired flatfoot in the adult: value of magnetic resonance imaging.

Dysfunction of the posterior tibial tendon is the most common cause of acquired flatfoot in adults; despite this, the condition is not commonly recognized. We report three cases with flatfoot secondary to spontaneous tendon rupture, in whom magnetic resonance imaging (MRI) was a helpful non-invasive technique to confirm the suspected diagnosis. This disabling entity, and the usefulness of MRI in the diagnosis and planning the appropriate treatment, are reviewed.