Surgical Outcomes and Complications of Pedicle Screw Fixation in 200 Cases of unstable Cervical Spinal Injuries - Comparison between Plate Systems and Rod Systems - Abstract
Introduction: Surgical outcomes and complications in the patients, who underwent posterior spinal fusion with pedicle screws for unstable cervical spinal injuries, were investigated comparing plate systems and rod systems. The relative merits of plate systems (non-constrained type) and rod systems (constrained type) were discussed. Summary of Background Data: Cervical pedicle screw fixation is an effective procedure for stabilizing an unstable motion segments, however it has not widely been used because it has generally been considered too risky due to the potential risk for injury neurovascular structures, such as vertebral arteries, spinal cord or nerve roots. The authors reported a study to introduce the imaging technique in which pedicle axis views were obtained using fluoroscope to show the screw entry point matched with trajectory angle.
Materials and Methods: A total of 200 consecutive patients (172 male and 28 female) who underwent pedicle screw fixation with pedicle axis view technique by fluoroscopy, were included in this study. The mean age of the patients at the time of surgery was 47±20 years (range 14-90). A hundred patients were treated with plate systems, and the other 100 with rod systems. Surgical outcomes such as operative time, blood loss, the number of fixed vertebra and the number of using pedicle screws were investigated. Screw malposition was classified either as Grade 0; intact, Grade I; screw exposure (<50% of the screw diameter outside the pedicle) or Grade II; pedicle perforation (>50% of the screw diameter outside the pedicle). Peri- and postoperative complications were also studied.
Result: The mean operative time was 111(plate; 98, rod; 125) min and mean blood loss was 184(plate; 220, rod; 147) ml. Of the 883 screws, 107 screws showed malposition (12% in total, 14% in plate system and 10% in rod system). And 71(8.0%) were in Grade I and 36 (4.1%) were in Grade II. There were 3 surgery-related complications: two penetrations into the vertebral artery by probe and one radiculopathy. There were 11 postoperative complications: 4 cases of instrumentation failure associated with loss of correction (three cases in plate systems and one case in rod systems), 4 cases with loss of correction (>10 degrees) and 3 deep wound infections.Pre- and postoperative tracheotomy was required in 27 patients (13.5%). However, the were easily performed, because those patients underwent posterior surgery alone without postoperative external fixation.
Discussion and Conclusion: Cervical pedicle screw fixation using a fluoroscopy assisted pedicle axis view technique provided good clinical result in both plate and rod systems. Although 107 of 883 screws demonstrated screw malposition, the incidence of complications associated with instrumentation was relatively low. There were less surgery-related complications in rod systems, comparing plate systems.