[Thrombosis of the posterior tibial artery complicating closed injury of the ankle].

Closed ankle injury without fracture is a common finding in the emergency room. Outcome is generally spontaneously favorable, the injury having no long-term clinical impact. Exceptionally, these injuries can be associated with arterial damage. We report a case of an apparently benign closed ankle injury which was found to be associated with serious arterial damage. Forced dorsal flexion of the ankle joint during a traffic accident caused an arterial lesion without any apparent damage to the bone and joints. The posterior tibial artery was interrupted leading to subacute ischemia of the foot. The diagnosis was established 17 days after trauma. Revascularization could not be achieved and leg amputation was necessary. This case illustrates the difficulties encountered in this type of vascular injury. Most cases in the literature have also involved late diagnosis with often serious clinical impact. Clinicians should be aware of this rare complication of apparently benign ankle injury because of the risk of major loss of function.