Brachial plexus palsy caused by secondary fracture displacement in a patient with closed clavicle fracture.

In adults, brachial plexus injury due to clavicle fractures is rare, and is most commonly caused by nonunion, malunited fragments, hypertrophic callus, or pseudoaneurysm of the subclavicular artery or vein. Brachial plexus palsy in acute fractures caused by direct fragment compression is exceptional. Conservative treatment of nondisplaced and displaced midclavicle fractures in adults usually produces satisfactory outcomes. This article presents a case of a 74-year-old man who sustained a closed, midshaft right clavicle fracture complicated by secondary displacement and brachial plexus injury. Initially, the fracture was nondisplaced, and he was treated conservatively. However, he returned 2 weeks later with shoulder pain and coldness, progressive numbness, and weakness of the right extremity. Physical examination revealed weakness of the flexion and extension of his elbow, wrist, and finger joints with slightly diminished right side radial pulsation. Radiographs demonstrated a displaced clavicle fracture with a vertically angulated intermediate fragment and narrowed costoclavicular space. Magnetic resonance imaging revealed bony fragments with a perifocal soft tissue mass encroaching on the brachial plexus and axillary artery. During surgery, the brachial plexus was found to be markedly stretched due to compression by the bony fragments and an organized blood clot. After meticulous neurolysis, the blood clot and intermediate bony fragments were removed and the distal fragments were reduced and fixed with a metal plate and interfragmentary screws. Secondary fracture displacement is possible after a nondisplaced clavicle fracture if the arm is not well protected, even if the original fracture appears stable and no neurological or circulatory symptoms are present.