1. Traumatic Atlanto-Occipital Dislocation in Children
by Nelson Astur, Paul Klimo, Jeffrey R. Sawyer, Derek M. Kelly, Michael S. Muhlbauer, and William C. Warner
J Bone Joint Surg Am
Volume 95(24):e194
December 18, 2013
©2013 by The Journal of Bone and Joint Surgery, Inc.

2. Figs. 1-A through 1-D The Traynelis classification system was used to identify the type of atlanto-occipital dislocation.
Figs. 1-A through 1-D The Traynelis classification system was used to identify the type of atlanto-occipital dislocation. Fig. 1-A Normal atlanto-occipital relationship. Fig. 1-B Type I: anterior displacement of the occiput over the atlas. Fig. 1-C Type II: longitudinal distraction. Fig. 1-D Type III: posterior displacement.
Nelson Astur et al. J Bone Joint Surg Am 2013;95:e194
©2013 by The Journal of Bone and Joint Surgery, Inc.

3. Figs. 2-A, 2-B, and 2-C Radiographic parameters of atlanto-occipital dislocation.
Figs. 2-A, 2-B, and 2-C Radiographic parameters of atlanto-occipital dislocation. Fig. 2-A The Powers ratio. B = basion, O = opisthion, A = anterior arch of atlas, and P = posterior arch of atlas. Fig. 2-B The Kaufman method; the width of the atlanto-occipital junction should not exceed 5 mm. Fig. 2-C The Wackenheim line is drawn along the clivus and should intersect the posterior half to third of the dens on a normal image.
Nelson Astur et al. J Bone Joint Surg Am 2013;95:e194
©2013 by The Journal of Bone and Joint Surgery, Inc.

4. Figs. 3-A through 3-G Case 13.
Figs. 3-A through 3-G Case 13. Fig. 3-A Lateral cervical spine radiograph showing atlanto-occipital dislocation. Figs. 3-B, 3-C, and 3-D Sagittal CT scans showing a Powers ratio measurement (1.12) (Fig. 3-B), measurement with the Kaufman method (8.24 mm) (Fig. 3-C), and the Wackenheim line anteriorly displaced with respect to the dens (Fig. 3-D). Fig. 3-E MRI showing dislocation and injury to the atlanto-occipital joint. Fig. 3-F Postoperative lateral radiograph showing the contoured rod and wires. Fig. 3-G Postoperative anteroposterior radiograph showing the contoured rod and wires.
Nelson Astur et al. J Bone Joint Surg Am 2013;95:e194
©2013 by The Journal of Bone and Joint Surgery, Inc.

5. Seven-year-old child with atlanto-occipital dislocation.
Nelson Astur et al. J Bone Joint Surg Am 2013;95:e194
©2013 by The Journal of Bone and Joint Surgery, Inc.

6. After halo application in the ICU, there was adequate alignment with mild distraction.
Nelson Astur et al. J Bone Joint Surg Am 2013;95:e194
©2013 by The Journal of Bone and Joint Surgery, Inc.

7. Radiograph obtained after deterioration of neurological status showed distraction of the atlanto-occipital junction.
Radiograph obtained after deterioration of neurological status showed distraction of the atlanto-occipital junction.
Nelson Astur et al. J Bone Joint Surg Am 2013;95:e194
©2013 by The Journal of Bone and Joint Surgery, Inc.

8. Illustrations showing the fixation structure with contoured loop rod and sublaminar wires.
Nelson Astur et al. J Bone Joint Surg Am 2013;95:e194
©2013 by The Journal of Bone and Joint Surgery, Inc.