The forgotten condyle: the appearance, morphology, and classification of occipital condyle fractures.

PURPOSE To evaluate the appearance, morphology, and treatment of occipital condyle fractures (OCF). METHODS Cases were collected by a retrospective and prospective analysis of teaching files and case logs. Patients' charts, when available, were reviewed for age, sex, mode of injury, physical examination, Glascow Coma Scale score, and associated injuries. Plain films and CT images were reviewed to determine OCF type and to assess for the presence of associated cervical spine and/or intracranial trauma. RESULTS Fifteen patients with OCF, 13 occurring in a 43-month period, were identified. Ten patients were involved in motor vehicle accidents. Severity of closed head injury and associated clinical findings were variable. Three patients had associated cervical spine fracture. According to the Anderson and Montesano classification, two patients (13%) had type I OCF, eight patients (54%) had type II OCF, and five (33%) had type III OCF. Fourteen of the fractures were identified on screening trauma head CT scans. Treatment varied according to the presence of associated injuries and stability of the cervical spine. CONCLUSIONS Although OCFs are rare, they will be encountered by most radiologists who see a significant amount of trauma. Type II OCFs were the most common fracture type in our series. Type III fractures were the second most common and potentially unstable. CT should be initiated at the level of the C-1 ring to screen for the presence of OCF in all patients who have suffered trauma.