Anterior ankle impingement.

Our understanding of the pathophysiology of anterior ankle impingement has steadily progressed since the princeps description almost 70 years ago. The same is true of diagnosis and treatment, which have greatly changed over time. The present study provides an update on this pathology, addressing the following questions: Anterior ankle impingement is suspected in case of anterior ankle pain reproducible by palpation and exacerbated by dorsiflexion imposed by the examiner or squatting, and Molloy's sign. Etiologies are varied: tumoral, post-traumatic, lateral ankle instability, osteoarthritis and microtrauma. Complementary cross-sectional imaging, and especially MRI, is indispensable for identifying the cause. A dichotic classification in terms of anterolateral impingement of tissular origin and anteromedial impingement of osteophytic origin is incompatible with current pathophysiological concepts. An etiological classification, completed by a topographic classification in 3 zones, provides a better guide for treatment strategy. Tumoral or post-traumatic impingement requires a specialized team. Impingement by microtrauma associated with instability or osteoarthritis is best treated arthroscopically, for exhaustive exploration of intra-articular elements that may be implicated. Treatment consists in removing osteophytes and any pathological synovial or ligamentous soft tissue. Anterior talofibular ligament or medial collateral ligament repair may be associated. Results can be expected to be good, with clear improvement in pain and function and excellent patient satisfaction. LEVEL OF EVIDENCE: V, expert opinion.