Fracture of the occipital condyles and associated craniocervical ligament injury: incidence, CT imaging and implications.

Thin section contiguous axial computer tomography (CT) was used to demonstrate fractures of the occipital condyle and craniocervical ligament injury. During a 12-month period, 55 consecutive patients who had sustained high energy blunt trauma to the head or upper cervical region were examined (38 male and 17 female, age range 3-80 years, median 24 years). If occipital condyle fracture was suspected clinically, CT was performed from C2 to the foramen magnum with two dimensional sagittal, coronal, and curvilinear reconstructions and employing bone and soft tissue windows. Occipital condyle fractures were classified according to Anderson and Montesano types 1, 2 or 3. Injury to the internal craniocervical ligaments was described. Nine of 55 patients had occipital condyle fractures (16.4%). Injury of the alar ligaments was demonstrated in four and tectorial membrane injury in two patients. Three of the nine patients had associated fractures of cervical vertebrae. Five of nine patients had a normal Glasgow coma scale on admission (55%) and in two patients the occupital condyle fracture was the only significant injury. Plain cervical radiographs were non-diagnostic. Two patients had significant pain and limited motion of the craniocervicum several months following injury. In conclusion, CT should be performed where there is a high clinical suspicion of occipital condyle fracture, that is based mainly on the mechanism of injury.