gms | German Medical Science

Transpedicular screws and posterior intersegmental fusion can result in nerve root and even spinal cord damage. Since 2000 our institution applies routinely during complex thoraco lumbar spine surgery with regional fusions multimodal intraoperative monitoring (MIOM) to reduce neurological complications.

MIOM with combined application of sensory spinal- and cortical evoked potentials and motor evoked potentials of spinal cord and muscles by electrical trascranial, spinal cord and pedicle-screw stimulation and continuous EMG.

In the period 2000-2004 233 fusion operations of the lumbar spine and thoraco-lumbar junction with MIOM have been applied: 98 scoliosis, 121 instabilities, 9 spinal stenosis, 5 tumors. Average MIOM 5h (1.3-15h). All monitorings were performed by the same neurophysiologist (first author).

Out of 233 monitoring cases in this study 149 have shown no difference of the potentials during the entire surgical procedure. 34 monitoring changes have been attributed to anaesthesia, while 50 were surgery associated.

In those 50 cases the surgeon has been informed immediately about changing of neural function to adapt his surgical procedure, i.e. change of position of the pedicle screws.

Based on MIOM data 11 cases indicated postoperative functional neurological deficits. Compared with the postoperative clinical neurological examinations 219 were true negative, 9 true positive, 3 false negative and 2 false positive, calculating a sensitivity of 92% and the specificity of 99% for the performed MIOM.

The result of the presented study indicate that the multimodal intraoperative monitoring is an effective method to protect nerve root and spinal cord function during thoraco-lumbar spine surgery applying pedical screws and therefore improving postoperative results by reducing the incidence of iatrogenic complications.