Anatomical considerations for percutaneous proximal humeral fracture fixation

Abstract

Purpose: To investigate the hypothesis that percutaneous wire fixation of proximal humeral fractures is prone to regional neurovascular injury. Materials and Methods: 40 cadaveric shoulders had percutaneous wires inserted from anterior and lateral humeral shaft entry points into the humeral head. The shoulders were then dissected to identify the neurovascular structures in this area. Results: The axillary nerve trunk and posterior circumflex humeral artery were found to be within the field of dissection. The axillary nerve was damaged on three occasions by the lateral wires, two of which were direct nerve penetrations. The anterior wires caused a single perineural injury of a terminal branch. The main neurovascular leash was 57 mm (range 35–70 mm) from the acromion tip laterally and 51 mm (range 35–85 mm) anteriorly, with a width of 6 mm (range 4–13 mm) laterally, and 12 mm (range 7–15 mm) anteriorly. Conclusions: Percutaneous wire stabilisation is an attractive fixation option but this study highlights the close proximity of the important neurovasculature. Such fixation should be performed utilising a limited open approach, with dissection to bone under direct vision, with the subsequent use of a drill-sleeve for soft-tissue protection.