OBJECTIVES No studies have compared monoaxial and polyaxial pedicle screws with regard to the von Mises stress of the instrumentation, intradiscal pressures of the adjacent segment and adjacent segment degeneration. METHODS Short-segment monoaxial/polyaxial pedicle screw fixation techniques were compared using finite element methods, and the redistributed T11-L1 segment range of motion, large...

See the article "Floor-Mounted Robotic Pedicle Screw Placement in Lumbar Spine Surgery: An Analysis of 1,050 Screws" Volume 20 on page 577.

BACKGROUND There is no study concerning safety and accuracy of pedicle screw placement in Marfan syndrome. The objective of this study is to investigate accuracy and safety of pedicle screw placement in scoliosis associated with Marfan syndrome. METHODS CT scanning was performed to analyze accuracy of pedicle screw placement. Pedicle perforations were classified as medial, lateral or anterior...

Boucher was the first to use screws that crossed through the strongest point of attachment of the facet joint into the pedicle and the body of the vertebra below. He declared a pseudorthrosis rate of 14% to 17% including multilevel fusions (1). The use of pedicle screw–assisted spinal stabilization has become increasingly popular worldwide. Pedicle screw systems engage all three columns of the ...

Pedicle screws are widely used for instrumentation of the thoracolumbar spine. The anatomic studies performed in the last two decades, detailing the complex morphometry and three-dimensional anatomy of the thoracolumbar pedicles, have enabled the emergence of the so-called "free-hand" technique of pedicle screw placement based exclusively on anatomical parameters. However, in the thoracic spine...

Study Design Retrospective clinical cohort study. Purpose To investigate whether the combined use of dynamic pedicle screws and polyaxial pedicle screws was effective on adjacent segment pathology (ASP). Overview of Literature Various screw and rod models have been recently developed for preventing adjacent segment disease, and hybrid systems have been described along with posterior instrum...

The purpose of our study was to determine the diagnostic power of three-dimensional reformatted multi-slice computerized tomography (CT) images on misplaced pedicle screws in spinal surgery. Eighty-four consecutive patients with 458 screws in situ were investigated prospectively using both axial CT slices and reformatted images after operation by two blinded investigators. All the screw misplac...

AIM Misplacement of pedicle screw is the serious complication of spinal surgeries. Intraoperative imaging techniques and navigation systems are currently in use for the prevention of this complication. The aim of this study was to document the results of our experience with the navigation and intraoperative imaging technique and to share our experience with our colleagues. MATERIAL AND METHOD...

STUDY DESIGN Evaluation using 3-dimensional screw trajectory software and computed tomographic scans. OBJECTIVE To investigate the anatomic feasibility of laminar screw placement in the upper thoracic spine compared with pedicle screw placement. SUMMARY OF BACKGROUND DATA Although laminar screws have been suggested as an alternative to pedicle screws in the upper thoracic spine, previous an...