Investigation of the Complications Associated with Thoracic Pedicle Screws

Abstract：Objective To analyze the complications of upper thoracic pedicle screw fixation in treatment of the upper thoracic spine disorders and the operative technique. Methods 68 cases with upper thoracic injury(384 screws in total)and 45 cases with upper thoracic fracture/ dislocation treated by using T1 ~4 pedicle screws from April 2009 to April 2012 were retrospectively analyzed and all above cases underwent Ⅰ stage posterior open reduction plus internal fixation;23 cases with tuberculosis and kyphosis underwent anterior debridement with autograft bone fusion plus internal fixation and posterior orthomorphia. Intraoperative probing and postoperative vertebral X-ray and CT scanning were taken to observe the location,angle of pedicle screw in thoracic spine,as well as its relation and distance with thoracic spine walls. Frankel grading and JOA scoring were determined for all patients pre and postoperatively. Results There were 54 pedicle screw(14. 06%)induced thoracic spinal wall injury. Of them,39 were lateral wall injuries(10. 16%),including 27 grade Ⅰ injuries(7. 03%)and 12 grade Ⅱ injuries( 3. 12%);15 medial wall injuries and all of them were grade Ⅰ injuries. No pedicle screw involving upper and lower wall injuries was observed;no pedicle screw induced injuries involving more than two walls was observed. All pedicle screws were successfully placed;loosening and dislocation were observed in two pedicle screws. Frankel grading showed no worsening in traumatic patients and JOA score for spine marrow functioning increased from preoperative 5. 9 to postoperative 11. 5 in nontraumatic patients;failure of fusion of planted bones,formation of pseudoarticulation or signs of segmental instability were not observed. Conclusion Upper thoracic pedicle screw fixation has relatively low incidence of complications and is a safe operation. Complications can be minimized by sufficient preoperative image studies of the pedicles,familiar with the feature of structure and reasonable surgery technique.