VASCULAR CONSIDERATIONS IN POSTERIOR MALLEOLUS FRACTURE SURGERY: THE PREVALENCE OF THE PERONEAL ARTERY COMMUNICATING BRANCH AND PERONEAL ARTERY DOMINANCE

Introduction: The risk of vascular injury is a rare but significant concern in posterior malleolus fracture (PMF) surgery, especially with the commonly employed posterolateral approach. Anatomical variations of the peroneal artery have been blamed for serious vascular complications with the PL approach. This study aims to investigate the prevalence of peroneal artery communicating branch (PACB) and peroneal artery dominant (PAD) lower limbs, i.e. where the posterior tibial artery is either atretic or absent proximal to the origin of the PACB. Methods: A historic cohort study was performed on 916 lower limb computed tomography angiographies (CTA). Patient data were stratified based on clinical indication for imaging, laterality, and the presence or absence of the communicating branch. Results: A PACB was identified in 288 (31.4%) of the cases. The prevalence was significantly higher in patients with PVD (n = 226 (78.5%)) compared to those imaged for trauma (n = 18), free fibula graft assessment (n = 16), or other vascular concerns (n = 28). Notably, in cases where the PACB was present, 10% had an absent proximal posterior tibial artery, thus making the lower limb PAD through the PACB. The PACB occurs approximately 4cm proximal to the joint, posing a substantial risk of arterial compromise if the posterolateral approach is used. Conclusion: Our findings reinforce the existing anatomical literature regarding the variability of peroneal artery branching and underscore the potential hazards of a posterolateral approach in PMF fixation. Inadvertent ligation of the communicating branch (PACB) may lead to ischaemic complications. Given the high prevalence of this variation, particularly in patients with PVD, the posterolateral approach should be approached with caution.