Placement and complications of cervical pedicle screws in 144 cervical trauma patients using pedicle axis view techniques by fluoroscope

Abstract

Cervical pedicle screw fixation is an effective procedure for stabilising an unstable motion segment; however, it has generally been considered too risky due to the potential for injury to neurovascular structures, such as the spinal cord, nerve roots or vertebral arteries. Since 1995, we have treated 144 unstable cervical injury patients with pedicle screws using a fluoroscopy-assisted pedicle axis view technique. The purpose of this study was to investigate the efficacy of this technique in accurately placing pedicle screws to treat unstable cervical injuries, and the ensuing clinical outcomes and complications. The accuracy of pedicle screw placement was postoperatively examined by axial computed tomography scans and oblique radiographs. Solid posterior bony fusion without secondary dislodgement was accomplished in 96% of all cases. Of the 620 cervical pedicle screws inserted, 57 (9.2%) demonstrated screw exposure (<50% of the screw outside the pedicle) and 24 (3.9%) demonstrated pedicle perforation (>50% of the screw outside the pedicle). There was one case in which a probe penetrated a vertebral artery without further complication and one case with transient radiculopathy. Pre- and postoperative tracheotomy was required in 20 (13.9%) of the 144 patients. However, the tracheotomies were easily performed, because those patients underwent posterior surgery alone without postoperative external fixation. The placement of cervical pedicle screws using a fluoroscopy-assisted pedicle axis view technique provided good clinical results and a few complications for unstable cervical injuries, but a careful surgical procedure was needed to safely insert the screws and more improvement in imaging and navigation system is expected.

Figures

Fig. 1

Illustrative setting of fluoroscope in order to obtain the left pedicle axis view

Fig. 2

Oblique radiograph shows the cortical circles of left C4–T1 pedicles. Left C6 pedicle is seen as a round circle just below the upper endplate and this is the pedicle axis view (Arrow)

Fig. 3

Axial CT scan of C5

Fig. 4

Screw placement; screw exposure (left) and pedicle perforation (right) in axial CT scans

Fig. 5

Imaging studies of an illustrative case. Preoperative sagittal and axial image of CT shows C6/7 fracture—dislocation, C5–7 lamina—vertebral body separation and left C5 and right C6 pedicle fracture without displacement (a, b). Good alignment after open reduction and a tracheal tube anterior to the cervical spine are seen on another sagittal image (c). Postoperative AP and lateral radiograph show good alignment and C5–7 pedicle screw fixation (d). Postoperative CT scans show good placement of pedicle screws at C5, C6, C7 levels (e)