A single fracture in the ring of vertebrae below the atlas: report of four cases.

A single fracture of the ring of a vertebra is a rare injury of the spine. In this report, we present five single fractures of the posterior ring of the cervical spine below the atlas from four patients after motor vehicle accidents. Initial radiographs failed to show any of these fractures; all were detected by computed tomography. Single ring fractures are stable and none of our patients presented with a neurological deficit. Patients were treated conservatively with a cervical collar or a cervicothoracic brace. They all recovered without any neurological abnormalities.