Usefulness of MR imaging in the detection of talar dome injuries

Patients with significant ankle injuries often have normal findings on conventional radiographs despite severe ligament, tendon, and bone injuries. MR imaging was used to assess the incidence of talar dome injuries in patients who had failed conservative therapy after ankle trauma.

MR images were obtained in 30 patients with persistent ankle pain 6 weeks after an injury. All patients had normal findings on conventional radiographs. Patients with clinical symptoms suggesting ligamentous instability were excluded from the study. Simplified MR sequences using coronal T1-weighted and short inversion time inversion recovery images were used. Total scan time for each patient was 11 min.

On MR imaging, 17 (57%) of 30 patients had injuries at the talar dome despite normal findings on conventional radiographs. Early detection resulted in cessation of physical therapy and casting of the ankle for 4 weeks. Ten of the patients with abnormalities on MR imaging underwent follow-up MR imaging within 1 year of first MR imaging, with resolution of the previously noted abnormalities. The 13 patients with normal findings on MR images 6 weeks after injury continued with physical therapy with subsequent resolution of their pain.

Limited MR images of the ankle are useful for detecting talar dome injuries. A significant incidence (57%) of talar dome injury occurred despite normal findings on conventional radiographs in patients with persistent ankle pain.