[Results of the treatment of odontoid fractures by osteosynthesis with a single axial screw].

PURPOSE OF THE STUDY: The authors present the clinical results of odontoid fracture treatment, using a single axial screw, with the aim to compare their results with the findings of other relevant studies, with focus on the use of either one or two axial screws.

MATERIAL: Thirty patients were included in the study, 16 men and 14 women at an average age of 56.1 years. They had findings of type II and "shallow" type III fractures, as evaluated on the basis of Anderson and D'Alonzo classification, and combined fractures. All were managed by the method of direct osteosynthesis of the dens with a single axial screw from the anterior approach in the years 1998 to 2005.

METHODS: The retrospective, cross-study analysis was based on records and clinical notes from the outpatient department and on radiographic materials from the department of radiology at follow-ups of 3, 6 and 12 months after surgery. The criteria assessed included screw insertion, quality of fusion during follow-up, and intra-operative and early and late post-operative complications.

RESULTS: Insertion of a screw was regarded as optimal in 24 (80 %) cases and suboptimal in six (20 %) cases. None of the patients required screw re-insertion. Evident fusion present at 12 months post-operatively was achieved in 18 (86 %) and questionable fusion in two patients. Non-union was recorded in one patient. Repeat operation was not indicated in any of the cases. There were no intra-operative complications. In six patients early complications occurred. Three patients died due to causes unrelated to the surgical procedure. Two patients had infectious complications not directly related to the surgery. One patient suffered from temporary dysphonia due to vocal chord edema.

DISCUSSION: For direct osteosynthesis of the dens, one or two screws can be used. Both methods have been studied in terms of biomechanics and clinical outcome, but none of the studies showed any significant differences between the two methods. Also the available Czech studies have paid only marginal attention to this issue.

CONCLUSIONS: Based on the analysis of patients' data and literature reports we can conclude that osteosynthesis employing a single axial screw gives results similar to that using two screws. The available biomechanical and clinical studies have not shown any statistically significant differences between the two methods. The results of our study are in agreement with the relevant literature data published so far. .