The radial nerve danger zone: A cadaver study

Distal humerus fractures are uncommon, comprising 2% of all fractures and a third of all humerus fractures. Open fractures, comminuted fractures and fracture dislocation of the elbow are often accompanied by severe soft tissue damage. External fixation of the humerus is indicated when severe soft tissue damage or the presence of infection warrants initial alternative immobilisation of the fractures around the elbow. External fixation allows for easy access for wound cleaning and dressing, stabilises fractures where vascular and nerve repair was done and allows for frame adjustments to improve alignment. External fixation allows for early mobilisation of adjacent joints and mobilisation of the patient. External fixation can cause pin tract sepsis, and injury to nerves and blood vessels and the surrounding soft tissue. The radial nerve is situated close to the humerus, and placing external fixation around the distal humerus may lead to nerve damage. The upper limb is innervated by a plexus of nerves arising from the ventral rami of the C5–T1 nerve roots. The ventral rami of the upper, middle and lower trunks divide into anterior and posterior divisions. The posterior divisions of all three trunks form the posterior cord. In the axilla, the radial nerve is located posterior to the axillary artery from where it runs inferiorly along the medial aspect of the proximal humerus. The radial nerve then descends along the radial groove to pierce the lateral intermuscular septum proximal to the lateral epicondyle where it runs between the brachialis and brachioradialis muscles. Abstract