Irreducible fracture-dislocations of the ankle associated with interposition of the tibialis posterior tendon: case report and review of the literature of a specific ankle fracture syndrome.

A severe closed pronation-eversion fracture-dislocation of the ankle that was irreducible by closed means was encountered. Exploration to accomplish open reduction revealed displacement of the tibialis posterior tendon through the diastasis between the distal tibia and fibula. The tibialis posterior tendon was found to pass posteriorly to an anteriorly between the distal tibia and fibula and laterally to medially across the anterior surfaces of the distal tibia and neck of the talus. Reduction was blocked by the tibialis posterior tendon in its abnormal course. After replacement of the tibialis posterior tendon in its anatomic position, reduction was accomplished. Internal fixation was then performed uneventfully. Two previous similar cases of irreducible ankle fractures due to displacement of the tibialis posterior tendon through the diastasis between the distal tibia and fibula have been reported in the literature. This uncommon syndrome is reported as a possible etiology to be considered when failure of reduction of an ankle fracture is encountered.