A 20-year-old man presented with right shoulder pain. He had been shoveling snow when his shovel struck a patch of ice, and he immediately felt pain in his shoulder. When he attempted to raise his arm, he noticed pain and clicking sensations. His medical history was significant for right clavicle fractures 12 and 4 years previously. Both injuries were managed nonoperatively, and normal function was restored.

Physical examination revealed a notable deformity of the right clavicle (Figure 1). The patient had normal right upper extremity strength with normal distal sensation and pulses. The deformity had minimal tenderness, but the patient reported pain with the passive cross-arm test (passive horizontal shoulder adduction). Plain radiography was performed (Figure 2).

QUESTION

Based on the patient's history, physical examination, and plain radiography, which one of the following is the most likely diagnosis?

• A. Acute nondisplaced fracture.

• B. Nonunion fracture.

• C. Pathologic fracture.

• D. Stress fracture.