To compare the mechanical effectiveness of a new conical screw design with a conventional cylindrical screw design, the screw insertion time, torque, and pull-out strength of single-pedicle screw and triangulated-pedicle screw constructs of each type of screw were compared in human cadaveric vertebral bodies. The time required to insert the conical screws was less than that required for cylindr...

OBJECTIVE A variety of different pedicle screws entry point techniques are used for the lumbar pedicle screws placement. This study reported Kim's entry point of lumbar pedicle screws with free hand technique and the accuracy of this technique. METHODS We retrospectively reviewed the 584 cases with free hand placed lumbar pedicle screw placement. The diagnosis included 491 cases with degenera...

To review existing publications on the safety of pedicle screw insertions in adolescent idiopathic scoliosis (AIS). Despite having increased risk for neurological and visceral injuries, the use of pedicle screws have led to increased correction rates in scoliosis surgery. A review was performed on topics pertinent to pedicle screw insertion in AIS, which included pedicle morphometry in AIS, str...

BACKGROUND Pedicle screws are used increasingly in spine surgery. Concerns of complications associated with screw breach necessitates accurate pedicle screw placement. Postoperative CT imaging helps to detect screw malposition and assess its severity. However, accuracy is dependent on the reading of the CT scans. Inter- and intra-observer variability could affect the reliability of CT scans to ...

STUDY DESIGN Prospective randomized controlled trial. OBJECTIVE The aim of this study was to monitor the quality control of robot-assisted pedicle screw fixation accuracy by using a cumulative summation (CUSUM) test at the initial stage of its application. SUMMARY OF BACKGROUND DATA Although robot-assisted pedicle screw fixation reduces screw misplacement rates and provides critical support...

Generally, bilateral pedicle screw fixation after Minimal Invasive (MIS) TLIF is accepted as a standard procedure for treating symptomatic spinal pathologies, such as degenerative spinal stenosis, spondylolisthesis, recurrent disc herniation, postlaminectomy instability, and deformity (10). Some authors have recently demonstrated that unilateral pedicle screw fixation is as effective for spinal...

Rod reduction to pedicle screws is used for a variety of spinal fixation procedures; however, it can alter the integrity of the screw-bone interface. The authors investigated the effect of pedicle fill (ratio of pedicle screw diameter to pedicle diameter) on the strength of the screw-bone interface after simulated rod reduction on 17 vertebrae (3 thoracolumbar spine specimens). Pedicle diameter...

BACKGROUND Posterior, atlantoaxial (AA) fusions of the cervical spine may include either standard (26 mm) or short (16 mm) C2 pedicle screws. This manuscript focused on an in vitro biomechanical comparison of standard versus short C2 pedicle screws to perform posterior C1-C2 AA fusions. METHODS Twelve human cadaveric spines underwent C1 lateral mass screw and standard C2 pedicle screw (n = 6)...

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 ...

BACKGROUND CONTEXT Achieving solid implant fixation to osteoporotic bone presents a clinical challenge. New techniques and devices are being designed to increase screw-bone purchase of pedicle screws in the lumbar spine via a novel cortical bone trajectory that may improve holding screw strength and minimize loosening. Preliminary clinical evidence suggests that this new trajectory provides scr...