Radiological Diagnosis of Axillary Artery and Brachial Plexus Involvement in a Proximal Humerus Fracture-Dislocation: A Case Report

Proximal humerus fracture-dislocations are uncommon in elderly patients and rarely associated with neurovascular compromise. The anatomical proximity of the axillary artery and brachial plexus to the humeral head places them at risk during trauma, but diagnosis can be challenging when distal pulses are preserved. We present the case of a 79-year-old female who sustained a fracture-dislocation of the proximal humerus following a low-energy fall. CT angiography demonstrated humeral head displacement into the axilla with bony impingement on the axillary artery compression and brachial plexus tenting without transection. The patient underwent reverse total shoulder arthroplasty with neurovascular exploration. The patient developed postoperative neuropraxia, which gradually improved with rehabilitation. This case highlights the diagnostic challenge of vascular injury without overt clinical signs and underscores the role of CT angiography in surgical planning. Early imaging allowed a multidisciplinary operative approach, facilitating preservation of vascular integrity and functional recovery. In patients with severely displaced proximal humerus fracture-dislocations, particularly when neurovascular injury is suspected, early CT angiography should be strongly considered to guide surgical decision-making and optimise outcomes.