Anatomic Relationship and Imaging Relevance of the Perforating Branches of the Peroneal Vessels to the Anterior Talofibular Ligament.

BACKGROUND: Patients frequently present to the emergency department after ankle injuries, and the anterior talofibular ligament (ATFL) is commonly damaged. Musculoskeletal ultrasound (US) can help to make a rapid diagnosis. There is a paucity of literature describing techniques to image the ATFL with US, and the complex ankle anatomy and potential pitfalls make imaging challenging.

OBJECTIVE: Our aim was to estimate prevalence of perforating branches (PBs) of the peroneal vessels and determine their most frequent position relative to the ATFL. If these vessels are located in a predictable position at the level of the ATFL, they may serve as a sonographic landmark for the correct imaging plane.

METHODS: Magnetic resonance imaging (MRI) scans of 105 ankles were reviewed to determine the PB prevalence and location at the ATFL. Inter-observer agreement was determined. Additionally, 16 ankles from 8 asymptomatic subjects were scanned using a high-frequency linear transducer and PB prevalence and location were noted.

RESULTS: By MRI, PBs were detected in 85% of the ankles and 93% of ankles after consensus. In 73% of cases with agreed PB visualization, vessels assumed a medial position with respect to the ATFL. By US, PBs could be seen in 100% of cases, with the arterial PB seen in 81% of cases and assuming a medial position in 88%.

CONCLUSIONS: PBs are often present, have a predictable course, and may be useful to help optimize US probe positioning when assessing the ATFL.