Posterior impingement in a pediatric population: a review and case report.

Fracture of the os trigonum is exceptionally rare, and it is even rarer in the pediatric age group. Symptomatically and radiographically, it may be confused with what is known as the os trigonum syndrome (constellation of symptoms produced by fracture of the lateral tubercle of the posterior talar process). The authors report a case of a fracture of the os trigonum, as well as its clinical features and management.