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[Isolated fractures of the atlas].

PURPOSE OF THE STUDY
To present the current tends in the diagnosis and management of isolated atlas fractures based on the retrospectively evaluated group of patients with this trauma.


MATERIAL
In the period from 1995 to 2002, we treated 486 injuries to the cervical spine at our department. Out of these, 19 patients sustained an isolated fracture of the first cervical vertebra. This group consisted of 12 men and seven women; the average age was 46.6 years. Neurological findings in 18 patients were classified as Frankel E and, in one, as Frankel A. The causes of injury included a fall from height in five patient, a fall in the street in five pedestrians, a car accident in five patients, a dive into shallow water in three and a shooting injury in one patient.


METHODS
We treated 16 patients conservatively, using a halo-vest in eight patients and a Philadelphia collar also in eight patients. In two patients with unstable atlas injury, we carried out C1-C2 transarticular stabilization according to Magerl. In the patient who had been shot, we removed the bullet transorally.


RESULTS
All patients healed completely without signs of instability. One patient with postraumatic pentaplegia, who died within 24 h of surgery due to septic shock, had not been included in the follow-up. Two patients reported neck pain at rest, three after exercise and 13 were without any pain. The patient after C1-C2 transarticular stabilization had a significant restriction of the range of motion in the cervical spine; the rest of the patients were without limitation. None of the patients showed any deterioration of neurological findings during the treatment, nor was any post-traumatic atlantoaxial instability recorded after the therapy was completed.


DISCUSSION
Isolated fractures of the atlas account for 1 to 2% of all spinal fractures. Many fractures may remain unnoticed and, therefore, it is important to X-ray patients with a symptomatic injury to the cervical spine in three standard projection planes (anteroposterior, lateral and transoral). When a fracture of the atlas is suspected, it is necessary to examine them by computed tomography to obtain a more accurate presentation of fracture lines. Views on the method of treating isolated fractures of the atlas, particularly unstable ones, are not consistent.


CONCLUSIONS
Isolated fractures of the first cervical vertebra, in terms of therapy, are stable and unstable. Stable fractures heal within 8 to 12 weeks. A Philadelphia collar or halo-vest provide sufficient immobilization. Surgical stabilization or a halo-vest immobilization for a period of 12 weeks are recommended in unstable injuries that are characterized by the lateral mass displacement of more than 7 mm or extension of the space before the dens (predental space) by more than 3 mm, or in which magnetic resonance imaging demonstrated injury to the transverse ligament. After the halo-vest removal, it is necessary to perform functional examination of the cervical spine for detection of potential atlantoaxial instability.