Diagnostic Ultrasonography of an Ankle Fracture Undetectable by Conventional Radiography: A Case Report.

OBJECTIVE: The purpose of this study is to present diagnostic ultrasonography assessment of an occult fracture in a case of persistent lateral ankle pain.

CLINICAL FEATURES: A 35-year-old woman presented to a chiropractic clinic with bruising, swelling, and pain along the distal fibula 3 days following an inversion ankle trauma. Prior radiographic examination at an urgent care facility was negative for fracture. Conservative care over the next week noted improvement in objective findings, but the pain persisted.

INTERVENTION AND OUTCOME: Diagnostic ultrasonography was ordered to assess her persistent ankle pain and showed a minimally displaced fracture of the fibula 4 cm proximal to the lateral malleolus. The patient was referred to her primary care physician and successfully managed with conservative care.

CONCLUSION: In this case, diagnostic ultrasonography was able to identify a Danis-Weber subtype B1 fracture that was missed by plain film radiography.