Spontaneous rupture of the peroneus longus tendon with fracture of the os peroneum.

Injuries of the peroneus longus and os peroneum are rarely reported. Two cases are presented, each occurring with an inversion stress and resultant audible snap. One patient sustained a complete spontaneous disruption of the peroneus longus with fracture of the os peroneum. This 64-year-old male was treated by excision of the proximal fracture fragment of the os peroneum and primary tendon repair. A 2-week prodrome of pain in the lateral aspect of the foot, preceded the rupture. Case 2, a 39-year-old female, was treated nonoperatively, and represents the clinical dilemma that may occur when the os peroneum is traumatized. It is emphasized that diagnosis of fracture of this ossicle can only be confirmed with operative excision and microscopic study. The authors recommend primary surgical treatment in those cases where continuity of the peroneus longus is disrupted. Where continuity is maintained, surgical exploration should be reserved for those cases that fail to respond to prolonged and intensive rehabilitation. Both patients regained full function and remain symptom free 11 and 10 months after treatment.