[Reposition of fragments of the posterior surface of the vertebral edge with intraoperative ultrasound guidance].

The question of whether fragments of the posterior vertebral surface have to be removed in every case remains to be answered. Nevertheless, in many cases it is important to establish the situation inside the spinal canal intraoperatively. To this end we have used intraoperative ultrasound in 21 cases. The results have always corresponded closely with the findings of preoperative and postoperative computed tomography. Under the influence of this method we have modified our operative procedure. The technique of intraoperative ultrasound and our current operative practice are described in the present paper. We use typical cases to show that intraoperative ultrasound of the spinal canal is a very useful technique for several reasons: Accurate depiction of the spinal canal is always possible without destabilizing the dorsal vertebral structures. The risks and disadvantages of intraoperative myelography are avoided. The method is easy and can be repeated as often as desired, an important advantage in checking the success of the removal of fragments and in reviewing the situation after transpedicular cancellous bone grafting.