TRAUMATIC SPONDYLOLISTHESIS OF THE AXIS

A series of 123 patients suffering traumatic spondylolisthesis of the axis is reported. This lesion is associated with extension and axial loading injury, and there is a high incidence of injuries of the face or scalp and of associated fractures of the upper cervical spine. There is a low incidence of neurological injury, which seems paradoxical in the presence of what appears to be gross instability, but protection from extremes of flexion and extension may be adequate treatment. Union is usual regardless of displacement. Traction is a safe means of treatment, but early walking in a halo support reduces time in hospital without jeopardising the result. Operation is needed only for chronic instabifity with or without pain, and anterior interbody fusion of C2-3 is then preferred in order to preserve rotation at the atlanto-axial joints. Traumatic spondylolisthesis of the axis involves bilateral fractures of the pedicles and may be caused by vehicular and diving accidents, or other deceleration injuries. The lesion, which has been called “hangman’s fracture ” , is characteristically produced by hyperexten-sion and axial loading, but has also been described as resulting from flexion and axial loading (Grogono 1954