Unsuspected "isolated" dislocation of the radial head in an adult

We have described a patient who as a child sustained a Monteggia's fracture that was neither diagnosed nor treated. Neurologic deficit and limitation of motion were clinically apparent. A high index of suspicion, careful examination of the patient, and high-quality roentgenograms should enable accurate diagnosis of this and similar lesions in less obvious cases, thus avoiding the complications of missed diagnosis.