Neurological Complications Associated with Pedicle Screw Displacement

We evaluated the location of 748 pedicle screws in a random sampling of 160 patients, and assessed the incidence of neurological complication in 685 consective patients who underwent lumbar and sacral spinal fusion using the Zielke transpedicular fixation system. 93% of 748 screws were right in the pedicle, while 6.2% penetrated the cortex of the pedicle, and 0.8% were completely misplaced from the pedicle. Neural injury relating to screw displacement occured in 11 of 685 cases, giving a neurological complication rate of 1.6%, all of which were nerve root injuries. This figure is consistant with other reports. 8 of these 11 cases had revision surgery with retrieval of the misplaced screw. 6 of 8 cases achieved satisfactory recovery and the remaining two cases resulted in some neurological deficits. 3 cases who did not require revision surgery because of minimum neurological deficits showed complete recovery.