The purpose of this study was to determine the change of fixation strength after adjusting the height of polymethylmethacrylate (PMMA)-augmented pedicle screws.Cement-augmented cannulated pedicle screws with or without PMMA augmentation with a radial hole in the distal third of the screw thread were inserted into synthetic bone blocks used to model osteoporosis. Screws were left unchanged (in s...

BACKGROUND The aim of this study was to evaluate the accuracy and feasibility of an individualized thoracic pedicle screw placement guide plate produced by 3-D laser printing. MATERIAL AND METHODS Thoracic pedicle samples of 3 adult cadavers were randomly assigned for 3-D CT scans. The 3-D thoracic models were established by using medical Mimics software, and a screw path was designed with scan...

STUDY DESIGN A retrospective review of charts, x-rays (XRs) and computed tomography (CT) scans was performed. OBJECTIVE To evaluate the accuracy of pedicle screw placement using a novel classification system to determine potentially significant screw misplacement. SUMMARY OF BACKGROUND DATA The accuracy rate of pedicle screw (PS) placement varies from 85% to 95% in the literature. This demo...

BACKGROUND Funnel technique is a method used for the insertion of screw into thoracic pedicle. AIM To evaluate the biomechanical characteristics of thoracic pedicle screw placement using the Funnel technique, trying to provide biomechanical basis for clinical application of this technology. METHODS 14 functional spinal units (T6 to T10) were selected from thoracic spine specimens of 14 fres...

BACKGROUND The biomechanical performance of the hooks and screws in spinal posterior instrumentation is not well-characterized. Screw-bone interface failure at the uppermost and lowermost vertebrae is not uncommon. Some have advocated for the use of supplement hooks to prevent screw loosening. However, studies describing methods for combined hook and screw systems that fully address the benefit...

BACKGROUND Transarticular screw fixation is used in the upper cervical and lumbar spine to achieve posterior spinal stability, and its biomechanical performance has been proven to be similar to that of pedicle screw fixation. However, few studies have reported the use of transarticular screw fixation in the upper thoracic spine. OBJECTIVE To biomechanically compare transarticular screws with ...

OBJECT There is a high probability of iatrogenic perforation of the vertebral pedicle wall during the application of subaxial cervical pedicle screw (CPS). The goal of this study was to evaluate the accuracy of CPS insertion at C3-C7 in vitro using novel calipers based on the gravity line. METHODS Nine cadaveric cervical spines underwent computed tomography scanning and preoperative design. A...

AIM Although conventional posterior lumbar interbody fusion (PLIF) using pedicle screws provides successful outcomes, pedicle screw related complications are sometimes noted. SPIRE? was invented as an interspinous fixation device (ISD) to replace pedicle screw. The aim of this study is to evaluate the clinical and radiological outcomes in patients who underwent unilateral PLIF using SPIRE? comp...

Introduction Lumbar fusion has proven to be an accepted treatment for a variety of indications. Pedicle screw fixation has historically been the gold standard for providing stabilization to the lumbar motion segment while the fusion matures. However, numerous studies have reported high complication rates, increased pain, and juxtalevel degeneration due to the size of the pedicle screw instrumen...

We used a navigation system to insert 128 pedicle screws into 69 vertebrae (L1 to L3) of 49 consecutive patients. We assessed the pedicle isthmic width and the permission angle for pedicle screw insertion. The permission angle is the angle defined by the greatest medial and lateral trajectories allowable when placing the screw through the center of the pedicle. The rate of narrow-width pedicles...