Objective: To describe the sonographic findings of lower extremity interosseous membrane disruption with computed tomographic and surgical correlation.
Methods: Three patients with sonographic evaluation of the lower extremity interosseous membrane were identified through the clinical experience of 1 author over a 5-year period. Sonographic images of the symptomatic and unaffected lower extremities were retrospectively characterized and correlated with computed tomographic and surgical findings by 2 fellowship-trained musculoskeletal radiologists.
Results: The normal interosseous membrane was identified in the asymptomatic lower extremities in all 3 patients, which appeared as a thin, hyperechoic (nearly equal to bone cortex) line, continuous from the tibia to the fibula. The abnormal interosseous membrane in all 3 cases appeared abnormally hypoechoic, poorly defined, and discontinuous at the tibia. A proximal fibular fracture was shown on sonography in 1 of 3 symptomatic lower extremities with radiographic evidence of a fracture. The sonographic findings correlated with the computed tomographic images. Distal tibiofibular syndesmosis injuries were confirmed and treated at surgery in 2 patients.
Conclusions: Sonography can show both normal and injured interosseous membranes of the lower extremity, as well as associated proximal fibular fractures.