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Positioning Thoracic Pedicle Screw Entry Point Using a New Landmark: A Study Based on 3-Dimensional Computed Tomographic Scan

Qi, Deng-bin PhD; Wang, Jing-ming MD; Zhang, Yong-gang PhD; Zheng, Guo-quan PhD; Zhang, Xue-song PhD; Wang, Yan MD

doi: 10.1097/BRS.0000000000000398

Study Design. A novel method to identify the entry point.

Objective. To quantify the position of thoracic pedicle screw entry points on the lamina at various segments of the thoracic vertebrae in normal subjects and patients with adolescent idiopathic scoliosis and propose a new technique to select entry points using a new landmark.

Summary of Background Data. Thoracic pedicle screws have been widely used in thoracic surgery, and the placement of pedicle screws has been studied extensively. However, there are only qualitative studies on selecting the entry point, and no study has quantified the position of entry points.

Methods. A retrospective study using 3-dimensional computed tomographic reconstruction techniques were used to study the morphology of thoracic vertebrae in 110 adolescents (56 cases of adolescent idiopathic scoliosis and 54 normal subjects). A quantitative area was used to select the entry point. Thoracic pedicle screw entry point was determined using the new landmark as reference and thoracic pedicle screws were placed in 21 patients. Postoperative computed tomographic scanning was performed to assess the safety and effectiveness of this entry point selection technique.

Results. We determined that the accuracy of pedicle screw placing after positioning entry point using the quantitative area was significantly superior to that after positioning entry point using the traditional method (P < 0.05).

Conclusion. The new technique quantifies the position of each thoracic pedicle screw entry point and it is convenient, easy to operate, and has relatively high accuracy of screw placement. This positioning technique can provide safe and accurate clinical guidance for selecting thoracic pedicle screw entry point.

Level of Evidence: 4

In Brief

We found a new method to locate the entry point in thoracic spine by using a new landmark in vertebral plate. We also verified the accuracy and found that the new technique can provide safe and accurate clinical guidance for selecting thoracic pedicle screw entry point.

Author Information

From the Department of Orthopaedics, Chinese People's Liberation Army General Hospital, Beijing, PR China.

Address correspondence and reprint requests to Yong-gang Zhang, PhD, Department of Orthopaedics, Chinese People's Liberation Army General Hospital (301 Hospital), 28 Fuxing Road, 100853, Beijing, PR China; E-mail:

Acknowledgment date: November 23, 2013. Revision date: February 20, 2014. Acceptance date: March 31, 2014.

The manuscript submitted does not contain information about medical device(s)/drug(s).

No funds were received in support of this work.

No relevant financial activities outside the submitted work.

© 2014 by Lippincott Williams & Wilkins