Surgical management of a ruptured peroneus longus tendon with a fractured multipartite os peroneum.

Injury of the peroneus longus tendon with concurrent fracture of the os peroneum is a seldom reported injury. This injury is probably underdiagnosed or misdiagnosed. The mechanism of this injury often involves sudden inversion, and therefore may often be misdiagnosed as a lateral ankle sprain or tendonitis. From the author's research review, this is the first reported case involving a fractured multipartite os peroneum with rupture of the peroneus longus tendon. The injury was diagnosed preoperatively by magnetic resonance imaging (MRI) as well as radiographs.