This article is more than 5 years old. Information may no longer be current.
MD-CT among techniques to improve safety of cervical pedicle screw insertion
Click Here to Manage Email Alerts
Researchers recently studied several cervical pedicle screw insertion techniques to help make the technically demanding procedure safer for both patient and surgeon and found that pedicle width dimension are smaller and more variable than the height dimensions.
“In addition, it has been clear that the cervical pedicle shows a narrow inner canal and thick outer cortex. Thus, the entry point and trajectories for cervical pedicle screw insertion should be determined individually by using preoperative MD-CT [multi-detector-CT] scan, and the inner pedicle width should be a key parameter to determine the screw dimensions, trajectories and entry point,” Pongsthorn Chanplakorn, MD, and colleagues, wrote in the study.
For the study they measured 740 pedicles, which were from 148 pedicles each at the five levels from C3 to C7 (74 pairs of right and left pedicles per level) in 74 patients. They then made cervical CT scans for each patient that consisted of 1-mm thick slices, which were retro-reconstructed in the sagittal and coronal planes to measure various cervical parameters.
“Of the numerous techniques for stabilizing the cervical spine, transpedicular screw fixation provides the greatest stability. However, the method of fixation is still technically demanding as it carries risk of catastrophic damages to the surrounding neurovascular structures. To avoid these potential complications, the detailed knowledge of the cervical pedicle anatomy and its architecture as well as the proper surgical techniques and implant design are essential,” Chanplakorn and colleagues wrote.
After analyzing these results, the investigators noted the cervical vertebra has a relatively small and narrow inner pedicle canal with a thick outer pedicle cortex. It also has a variable pedicle width and an inconsistent transverse angle, according to the investigators.
“To enhance the safety of CPS [cervical pedicle screw] insertion, the entry point and trajectories should be determined individually by using preoperative MD-CT scan and the inner pedicle width should be a key parameter to determine the screw dimensions,” they wrote. – Robert Linnehan
Disclosure: The authors have no relevant financial disclosures.
Collapse
Chanplakorn P. BMC Musculoskeletal Disorders. 2014;doi: 10.1186/1471-2474-15-125.
Click Here to Manage Email Alerts