Relationship between the Axillary Nerve and Accompanying Vessels and Proximal Humeral Locking Plates in Japanese: An MRI Study

We investigated the anatomical features of the axillary nerve and its accompanying vessels with respect to the lateral wall of the greater tuberosity, focusing on the relationship between the neurovascular bundle and the proximal humeral locking plates. Magnetic resonance images of 30 Japanese patients’ shoulders were examined. Oblique sagittal images across the greater tuberosity and the neurovascular bundle, which contain the axillary nerve and posterior circumflex humeral artery and vein, were obtained. The distance between the superior aspect of the greater tuberosity and the superior and inferior borders of the neurovascular bundles was measured at the anterior, middle, and posterior edges of the greater tuberosity. The neurovascular bundle was 28.5-36.7 mm, 32.6-41.3 mm, and 38.1-47.5 mm distal to the superior aspect of the greater tuberosity at the anterior, middle, and posterior edges, respectively. We evaluated the relationship between the neurovascular bundle and 3 different locking plates, which were placed at the lateral aspect of the greater tuberosity. Only 3 or four locking screws at the most proximal part could be safely inserted without axillary nerve interference.