Full video article: [ Ссылка ]
Treatment of unstable dens fractures with posterior transarticular C1-C2 arthrodesis provides a biomechanically stable construct, even when poor bone quality is present, and a low rate of complications even in elderly patients; however, when this method of fixation is performed, cervical spine rotation is substantially reduced as compared with that associated with alternative fixation techniques.
The patient is placed in a prone position, and the head is fixed in a Mayfield clamp. Exact positioning of the patient and use of biplanar image intensification are mandatory for this procedure. A small posterior incision is performed from just below the external occipital protuberance to C3, and dissection is carried out down to the posterior arch of C1 and C2. The guiding Kirschner wires and the screws are passed through two separate stab incisions at the level of the spinous process of T1 or T2. With this technique, it is possible to achieve the appropriate entrance angle at the entry point at C2. After the exposure of C1 and C2 is completed, a wire loop is passed around the posterior arch of C1. The Kirschner wires are passed through the caudal incisions to the entry points of the screws at the lamina of C2.The guiding wires are aimed above the lower rim of the anterior arch of C1. The guiding wires are then replaced by screws. A rectangular corticocancellous graft is harvested from the ilium (about 3 cm) and shaped into an H configuration on the basis of the area that would allow it to fit between the spinous process of C2 and the posterior ring of C1. Finally, one wire end of the loop around C1 is guided underneath the spinous process of C2 and the free ends are tightened over the graft, providing a Gallie-type fusion.
