Identification of Peroneal Tenosynovitis by Point-of-Care Ultrasonography.

Background: Ankle pain is a frequent chief complaint, and although peroneal tendon disorders are relatively uncommon, if treated inappropriately they may cause persistent pain and dysfunction. Peroneal tendon disorders, including the tendon sheath inflammatory condition tenosynovitis, are a major cause of chronic lateral ankle pain. Although magnetic resonance imaging has emerged as the modality of choice to assess the majority of these injuries, dynamic ultrasonography detects tendon pathology such as tenosynovitis.

Case Report: A 69-year-old woman presented to the Emergency Department (ED) after several months of atraumatic, progressive right foot and ankle pain. On physical examination, she had swelling and point tenderness posterior and inferior to the lateral malleolus, which was exacerbated by eversion. Plain radiography of the foot and ankle showed only soft tissue swelling. Bedside ultrasonography performed by the emergency physician quickly identified findings consistent with peroneal tenosynovitis without tears. Management with a walking boot and nonsteroidal antiinflammatory drugs was initiated prior to discharge. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: In this case of peroneal tenosynovitis, point-of-care ultrasonography was used to promptly and accurately identify hyperemia, synovial thickening, and a marked effusion within the right peroneal tendon sheath. Nonoperative treatment of tenosynovitis was initiated in the ED while findings were subsequently confirmed with magnetic resonance imaging. Emergency physicians should be aware of the utility of identifying tenosynovitis by point-of-care ultrasonography, which can expedite nonoperative management and prevent long-term complications.