A Novel Anatomical Description of the Normal Terminal Fibular Artery and the Terminal Fibular Window: Radiological Findings and Surgical Implications

A novel anatomical description and radiological finding, related to the anatomical course of the terminal fibular artery (FibA) was recently reported. In the article, the authors found the terminal FibA to change its course, from being posterior and medial to the fibula to surface anteriorly and laterally before residing below the tibiofibular interosseous membrane, in what the authors named the Terminal Fibular Window (TFW). These findings and descriptions were crucial in developing a new technique to access the terminal FibA for limb salvage bypass operations. The aim of this study is to assess whether the new anatomical description of the terminal FibA course and the TFW, are the normal anatomy, or whether these reported cases were anatomical variations. Two separate teams working independently conducted a retrospective analysis at a single tertiary centre between 2018 and 2019. Computed tomography (CT) angiography scans of the lower limbs were analyzed for the FibA course, and its terminal position was recorded. CT scans that did not have contrast or were found to have an occluded FibA were otherwise excluded. A total of 916 CT lower limb angiography scans were performed during this period. After the first 250 scans were studied and analyzed, the terminal FibA course and accompanying TFW were present in 100% of scans, thus the study was stopped. The commonest indications for the CT scans were peripheral vascular disease (44%), trauma (21%), acute limb ischaemia (15%), and pseudoaneurysm (5%). The anatomical course of the terminal FibA and the TFW were present on every CT. The mean size TFW in the right leg was 7.7 mm (range: 2-14 mm) compared to 8.2 mm (range: 3-16 mm) in the left leg. This study demonstrates that the newly described terminal FibA anatomical course and the TFW are the normal anatomy. Although this has important clinical and surgical implications in limb salvage procedures, a wider study will be required to assess implications in other subspecialty fields.