History: History is of a fracture that may or may not have been treated by a physician. The individual may report pain, swelling (edema), instability, or deformity at the site of a previously broken bone. If the fracture was in a lower extremity, the individual may report difficulty bearing weight through the limb.
Physical exam: The exam reveals the deformity of a malunion or the instability of a nonunion. Touching with the hands (palpation) may reveal tenderness.
Tests: Plain x-rays demonstrate the fracture malunion or nonunion. CT scan, MRI, or bone scan may help further define the condition.
Source: Medical Disability Advisor