Syndesmosis sprains of the ankle : The influence of heterotopic ossification

Diastasis of the ankle syndesmosis without fracture is an uncommon injury. We present the results of bone scintigraphy as well as stress radiographs of the ankle performed on 27 athletes with suspected acute diastasis of the ankle without fracture. Scintigraphy is a reliable procedure to guide initial management of those patients in whom stress radiographs of the ankle cannot be obtained because of pain or swelling, or in whom the radiographs were considered unreliable. Scintigraphy correctly identified all 20 patients with positive stress tests (sensitivity = 100%). Two of seven patients with negative stress tests had positive scans (specificity = 71%), for an accuracy of 93%. We feel that scintigraphy is of value in a small subset of patients with suspected acute diastasis of the ankle syndesmosis on whom stress radiographs cannot be performed, or are considered inadequate in the immediate postinjury period.