Aims. Vascular compromise due to arterial injury is a rare but serious complication of a proximal humeral fracture. The aims of this study were to report its incidence in a large urban population, and to identify clinical and radiological factors which are associated with this complication. We also evaluated the results of the use of our protocol for the management of these injuries. Methods. A total of 3,497 adult patients with a proximal humeral fracture were managed between January 2015 and December 2022 in a single tertiary trauma centre. Their mean age was 66.7 years (18 to 103) and 2,510 (72%) were female. We compared the demographic data, clinical features, and configuration of those whose fracture was complicated by vascular compromise with those of the remaining patients. The incidence of vascular compromise was calculated from national population data, and predictive factors for its occurrence were investigated using univariate analysis. Results. A total of 18 patients (0.5%) had a proximal humeral fracture and clinical evidence of vascular compromise, giving an annual incidence of 0.29 per 100,000 of the population. Their mean age was 68.7 years (45 to 92) and ten (56%) were female. Evidence of a mixed pattern neurological deficit (brachial plexus palsy) (odds ratio (OR) 380.6 (95% CI 85.9 to 1,685.8); p < 0.001), complete separation of the proximal shaft from the humeral head with medial displacement (OR 39.5 (95% CI 14.0 to 111.8); p < 0.001), and a fracture-dislocation (OR 5.0 (95% CI 1.6 to 15.3); p = 0.015) were all associated with an increased risk of associated vascular compromise. A policy of reduction and fixation of the fracture prior to vascular surgical intervention had favourable outcomes without vascular sequelae. Conclusion. The classic signs of distal
