Lyndon William Mason

Aims Posterior malleolar (PM) fractures are commonly associated with ankle fractures, pilon fractures, and to a lesser extent tibial shaft fractures. The tibialis posterior (TP) tendon entrapment is a rare complication associated with PM fractures. If undiagnosed, TP entrapment is associated with complications, ranging from reduced range of ankle movement to instability and pes planus deformities, which require further surgeries including radical treatments such as arthrodesis. Methods The inclusion criteria applied in PubMed, Scopus, and Medline database searches were: all adult studies published between 2012 and 2022; and studies written in English. Outcome of TP entrapment in patients with ankle injuries was assessed by two reviewers independently. Results Four retrospective studies and eight case reports were accepted in this systematic review. Collectively there were 489 Pilon fractures, 77 of which presented with TP entrapment (15.75%). There were 28 trimalleolar fractures, 12 of which presented with TP entrapment (42.86%). All the case report studies reported inability to reduce the fractures at initial presentation. The diagnosis of TP entrapment was made in the early period in two (25%) cases, and delayed diagnosis in six (75%) cases reported. Using modified Clavien-Dindo complication classification, 60 (67%) of the injuries reported grade IIIa complications and 29 (33%) grade IIIb complications. Conclusion TP tendon was the commonest tendon injury associated with pilon fracture and, to a lesser extent, trimalleolar ankle fracture. Early identification using a clinical suspicion and CT imaging could lead to early management of TP entrapment in these injuries, which could lead to better patient outcomes and reduced morbidity. Cite this article: Bone Jt Open 2024;5(3):252–259.

The posterior malleolus of the tibia is commonly accessed surgically through the posterolateral approach. This approach gives good access to the fibula and lateral aspect of the posterior tibia, however; there is little known on the vascular risks with this approach. The aim of this study was to assess and describe the anatomy of the fibular artery and its branches at the ankle region and relate it to the surgical access of the posterior malleolus. Eleven cadaveric foot and ankle specimens were dissected in layers, preserving the fibular artery, anterior tibial artery (ATA), and posterior tibial artery (PTA). Five distinct variations were found in the fibular artery: variable terminal branching with a hyperplastic fibular artery; a superficially located fibular artery; variation in the level and number of anastomoses; variation in the muscular branches; and a variable anterior perforating branch. The mean proximal distance from a horizontal line drawn through the medial protuberance of the medial malleolus of the tibia (horizontal line reference point—HLRP) to the posterior communicating branch of the fibular artery was 37.93 mm (range 19.03–85.43 mm). The mean proximal distance between HLRP and the anterior perforating branch of the fibular artery was 44.23 mm (range 35.44–62.32 mm). In 10 specimens, the fibular artery was immobile distal to its anterior perforating branch. The posterolateral approach specifically puts the fibular artery at risk and knowledge of its anatomy and variability is important when undertaking this approach. Understanding the common variations within the ankle's arterial anatomy can help surgeons protect these vessels from damage during the surgical approach.