[3D Fluoroscopy-Navigated Magerl Fusion of the 1st and 2nd Cervical Vertebra].

Background: Treatment of type II fractures of the odontoid process is still controversial. Besides conservative treatment, there are surgical options, including anterior screw fixation, as first described by Böhler and Magerl, or procedures using a dorsal approach. Many authors prefer dorsal fusion of C1 and 2, due to the reliable, biomechanical stability. In this context, pedicle screw fixation, as described by Harms, and transarticular screw fixation of the atlantoaxial joints, as described by Magerl, have to be mentioned. With the use of intraoperative fluoroscopic navigation, the risk of neurovascular lesions caused by abortive drilling or malposition of screws has been significantly decreased. In 1993, Eysel and Roosen established a subclassification of type II fractures of the odontoid process and gave treatment recommendations for each of the three subtypes. While there was an outcome for type A and B fractures treated by anterior screw fixation, the authors recommended performing dorsal stabilisation at type C fractures. Indication: In accordance with the recommendations of Eysel and Roosen, an 82 year old man, suffering from a type II C fracture of the odontoid process, underwent navigated, transarticular screw fixation of C1 and C2. Method: Once the 3D-fluoroscopy scan had been performed, the correct drilling direction in the axial, coronary and sagittal views of C1 and 2 was found using the navigated drillguide. After K-wires had been inserted in this direction on both sides, a second 3D-scan was performed to recontrol placement of the K-wires. Cannulated screws were introduced and the rods were installed, bearing the atlas hook to fixate the posterior atlas. Conclusion: In summary, dorsal, transarticular fusion of C1 and C2 is a successful treatment option, rarely leading to complications and is accompanied by reduced radiation exposure to the operating team.
(Georg Thieme Verlag KG Stuttgart · New York.)