Observation of computed tomography images of placing screws in the injured vertebra for different types of pedicle fractures

HU Hai-gang; TAN Lun

doi:10.3969/j.issn.2095-252X.2014.01.010

Abstract：Objective To investigate the safety of the treatment of thoracolumbar fractures by placing screws in the injured vertebra through observing the screw placement for different types of pedicle fractures based on the Computed Tomography ( CT ) images.Methods 56 patients with single-segment thoracolumbar fractures underwent the treatment of posterior internal ifxation with screws placed in the injured vertebra from June 2008 to June 2011 in our hospital. Preoperatively the standard Digital Radiography ( DR ) and CT were performed routinely in all the patients. Relevant images of the injured pedicles were kept by the picture archiving and communication system ( PACS ). The integrity and position of the fractured pedicles were observed, and the types of fractures were classiifed. Postoperatively the placed screws were observed based on the CT images. The Youkilis standard was used to evaluate the accuracy of pedicle screws.Results Pedicle fractures were divided into 3 main types, including fractures of the junction of pedicle and vertebra, pedicle waist fractures and fractures of the junction of pedicle and lamina. 105 pedicle screws were placed in 56 patients, with 57 screws at the left side and 48 screws at the right side. Unilateral pedicle screws were used in 7 patients. The postoperative CT images showed 98 screws were placed in the bone cortex completely and 7 screws were deviated, without any relevant clinical symptoms. The screw position was graded by the Youkilis standard, including I degree in 98 cases, II degree in 7 cases, III degree in 0 case. In this group, such screws to be above or in front of the vertebral body were not found. 1 patient had cerebrospinal lfuid leakage postoperatively, but no complications such as incision infection or the exacerbation of iatrogenic spinal cord dysfunction occurred. The failure of internal ifxation was noticed in 2 cases in the latest follow-up ( screw loosening and breakage in 1 case respectively ).Conclusions The placement of screws in the injured vertebra is a safe, feasible and reliable method in the clinical treatment of thoracolumbar fractures, with the complications not increased. However, the indications of placing pedicle screws should be mastered preoperatively, and the nail point and direction and the screw size and length should be grasped during the surgery, with the individualized surgical plan made based on the CT images.