A comparative cadaveric biomechanical study of bilateral FacetFuse transfacet pedicle screws versus bilateral or unilateral pedicle screw-rod construct.

Background: Achieving optimal immediate stability is crucial in lumbar fusion surgeries. Traditionally, four pedicle screws have been utilized to provide posterior stability at the L5-S1 level. However, the use of bilateral transfacet pedicle screws (TFPS) as an alternative construct has shown promising results in terms of biomechanical stability.

Robot-assisted screw fixation in a cadaver utilizing magnetic resonance imaging-based synthetic computed tomography: toward radiation-free spine surgery. Illustrative case.

Background: Synthetic computed tomography (sCT) can be created from magnetic resonance imaging (MRI) utilizing newer software. sCT is yet to be explored as a possible alternative to routine CT (rCT). In this study, rCT scans and MRI-derived sCT scans were obtained on a cadaver.

In Vitro Biomechanics of Human Cadaveric Cervical Spines With Mature Fusion.

Background: This study sought to compare index and adjacent-level biomechanics of cadaveric specimens with mature fusion versus normal spines in intact and acutely fused conditions.

Methods: Eight human cadaveric cervical spines with mature fusion across 1 to 3 levels were studied. Intervertebral angular range of motion (ROM) was determined at fused and adjacent levels during pure moments inducing flexion-extension (FE), lateral bending (LB), and axial rotation (AR).

Assessment of Surgical Procedural Time, Pedicle Screw Accuracy, and Clinician Radiation Exposure of a Novel Robotic Navigation System Compared With Conventional Open and Percutaneous Freehand Techniques: A Cadaveric Investigation.

Study Design: Cadaveric study.

Objective: To evaluate accuracy, radiation exposure, and surgical time of a new robotic-assisted navigation (RAN) platform compared with freehand techniques in conventional open and percutaneous procedures.

Methods: Ten board-certified surgeons inserted 16 pedicle screws at T10-L5 (n = 40 per technique) in 10 human cadaveric torsos.

Robotic Spine Surgery: Current State in Minimally Invasive Surgery.

Study Design: Narrative review.

Objectives: Robotic systems in spinal surgery may offer potential benefits for both patients and surgeons. In this article, the authors explore the future prospects and current limitations of robotic systems in minimally invasive spine surgery.

Three-dimensional assessment of robot-assisted pedicle screw placement accuracy and instrumentation reliability based on a preplanned trajectory.

Objective: Robotic spine surgery systems are increasingly used in the US market. As this technology gains traction, however, it is necessary to identify mechanisms that assess its effectiveness and allow for its continued improvement. One such mechanism is the development of a new 3D grading system that can serve as the foundation for error-based learning in robot systems.

Variations Among Human Lumbar Spine Segments and Their Relationships to In Vitro Biomechanics: A Retrospective Analysis of 281 Motion Segments From 85 Cadaveric Spines.

Background: Biomechanical properties of intact spinal motion segments are used to establish baseline values during in vitro studies evaluating spinal surgical techniques and implants. These properties are also used to validate computational models (ie, patient-specific finite element models) of human lumbar spine segments. Our laboratory has performed a large number of in vitro mechanical studies of lumbar spinal segments, using a consistent methodology.

Evaluation of abnormal styloid anatomy as a cause of internal jugular vein compression using a 3D-printed model: a laboratory investigation.

This study used a 3-dimensional (3D) craniocervical junction model of styloidogenic jugular venous compression (SJVC) syndrome to simulate and evaluate intracranial pressure (ICP) after internal jugular vein (IJV) compression by an elongated styloid process during axial rotation. The 3D-printed model created using data from an SJVC-syndrome patient included an articulating occipital-cervical junction, simplified arteriovenous system, gauge to measure simulated ICP, fixed obstruction simulating left-sided venous occlusion, and right-sided vascular tubing to simulate IJV compression. The model was rotated axially to its extreme right and left; maximum degree of motion and pressure were recorded for 3 cycles.

Navigated robotic assistance improves pedicle screw accuracy in minimally invasive surgery of the lumbosacral spine: 600 pedicle screws in a single institution.

Background: In the emerging field of robot-assisted spine surgery, radiographic evaluation of pedicle screw accuracy in the surgical setting is of high interest. Advances in medical imaging have improved the accuracy of pedicle screw placement, from fluoroscopy-guided to computer-aided navigation.

Methods: A retrospective, institutional review board-exempt review of the first 106 navigated robot-assisted spine surgery cases was performed.

New spinal robotic technologies.

Robotic systems in surgery have developed rapidly. Installations of the da Vinci Surgical System® (Intuitive Surgical, Sunnyvale, CA, USA), widely used in urological and gynecological procedures, have nearly doubled in the United States from 2010 to 2017. Robotics systems in spine surgery have been adopted more slowly; however, users are enthusiastic about their applications in this subspecialty.

Does the accuracy of pedicle screw placement differ between the attending surgeon and resident in navigated robotic-assisted minimally invasive spine surgery?

Robotic assistance with integrated navigation is an area of high interest for improving the accuracy of minimally invasive pedicle screw placement. This study analyzes the accuracy of pedicle screw placement between an attending spine surgeon and a resident by comparing the left and right sides of the first 101 consecutive cases using navigated robotic assistance in a private practice clinical setting. A retrospective, Institutional Review Board-exempt review of the first 106 navigated robot-assisted spine surgery cases was performed.

Navigated robotic assistance results in improved screw accuracy and positive clinical outcomes: an evaluation of the first 54 cases.

Computer-aided navigation and robotic guidance systems have become widespread in their utilization for spine surgery. A recent innovation combines these two advances, which theoretically provides accuracy in spinal screw placement. This study describes the cortical and pedicle screw accuracy for the first 54 cases where navigated robotic assistance was used in a surgical setting.

Comparing the Biomechanical Stability of Cortical Screw Trajectory Versus Standard Pedicle Screw Trajectory for Short- and Long-Segment Posterior Fixation in 3-Column Thoracic Spinal Injury.

Background: Information on the performance of posterior fixation with cortical screw (CS) versus pedicle screw (PS) trajectories for stabilizing thoracolumbar burst fractures is limited. Therefore, we sought to analyze stability with CS versus PS in short- and long-segment fixations using a 3-column spinal injury model.

Methods: Nondestructive flexibility tests: (1) intact, (2) intact + short fixation, (3) intact + long fixation, (4) after burst fracture, (5) short fixation + burst fracture, and (6) long fixation + burst fracture using thoracic spine segments (7 CS, 7 PS).

Pedicle screw accuracy in clinical utilization of minimally invasive navigated robot-assisted spine surgery.

In the emerging field of robot-assisted spine surgery, the radiographic evaluation of pedicle screw accuracy in clinical application is an area of high interest. This study describes the pedicle screw accuracy of the first 56 consecutive cases in which navigated robotic assistance was used in a private practice clinical setting. A retrospective, Institutional Review Board-exempt review of the first 56 navigated robot-assisted spine surgery cases was performed.

Ensuring navigation integrity using robotics in spine surgery.

There are potential pitfalls associated with the pursuit of accurate surgical navigation, such as vulnerability of the reference array to accidental dislodgment and damage or soiling of tracking arrays on tools. Additionally, there are hazards encountered when attempting accurate robotic screw placement in spine surgery, including skiving of the tool on bone, displacement of the robotic arm, or patient movement. Proven techniques are needed to address and mitigate these issues to ensure that navigation integrity is maintained and screw placement is accurate when using navigated robotic surgical guidance systems.

Biomechanical Effects of an Oblique Lumbar PEEK Cage and Posterior Augmentation.

Objective: Lumbar interbody spacers are widely used in lumbar spinal fusion. The goal of this study is to analyze the biomechanics of a lumbar interbody spacer (Clydesdale Spinal System, Medtronic Sofamor Danek, Memphis, Tennessee, USA) inserted via oblique lumbar interbody fusion (OLIF) or direct lateral interbody fusion (DLIF) approaches, with and without posterior cortical screw and rod (CSR) or pedicle screw and rod (PSR) instrumentation.

Methods: Lumbar human cadaveric specimens (L2-L5) underwent nondestructive flexibility testing in intact and instrumented conditions at L3-L4, including OLIF or DLIF, with and without CSR or PSR.

First spine surgery utilizing real-time image-guided robotic assistance.

Robotics in spinal surgery has significant potential benefits for both surgeons and patients, including reduced surgeon fatigue, improved screw accuracy, decreased radiation exposure, greater options for minimally invasive surgery, and less time required to train residents on techniques that can have steep learning curves. However, previous robotic systems have several drawbacks, which are addressed by the innovative ExcelsiusGPS robotic system. The robot is secured to the operating room floor, not the patient.

Biomechanical Evaluation of Cervicothoracic Junction Fusion Constructs.

Objective: We studied the effect of different cervicothoracic construct design variables on biomechanical stability in vitro.

Methods: Six fresh-frozen human cadaveric spines (C5-T4) were used. After intact analysis, each specimen was destabilized and reconstructed, with all groups having 4.

Impact of Connector Placement and Design on Bending Stiffness of Spinal Constructs.

Objective: To evaluate the stability of multiple rod-connector construct designs using a mechanical 4-point bending testing frame.

Methods: A mechanical study was used to evaluate the bending stiffness of 3 connectors across 12 different configurations of rod-connector-rod constructs. Stability was evaluated in flexion-extension and lateral bending.

Pedicle screw accuracy assessment in ExcelsiusGPS® robotic spine surgery: evaluation of deviation from pre-planned trajectory.

Background: The ExcelsiusGPS® (Globus Medical, Inc., Audubon, PA) is a next-generation spine surgery robotic system recently approved for use in the United States. The objective of the current study is to assess pedicle screw accuracy and clinical outcomes among two of the first operative cases utilizing the ExcelsiusGPS® robotic system and describe a novel metric to quantify screw deviation.

Biomechanical evaluation of the ProDisc-C stability following graded posterior cervical injury.

OBJECTIVEThere are limited data regarding the implications of revision posterior surgery in the setting of previous cervical arthroplasty (CA). The purpose of this study was to analyze segmental biomechanics in human cadaveric specimens with and without CA, in the context of graded posterior resection.METHODSFourteen human cadaveric cervical spines (C3-T1 or C2-7) were divided into arthroplasty (ProDisc-C, n = 7) and control (intact disc, n = 7) groups.

Biomechanical evaluation of interbody fixation with secondary augmentation: lateral lumbar interbody fusion versus posterior lumbar interbody fusion.

Background: Many approaches to the lumbar spine have been developed for interbody fusion. The biomechanical profile of each interbody fusion device is determined by the anatomical approach and the type of supplemental internal fixation. Lateral lumbar interbody fusion (LLIF) was developed as a minimally invasive technique for introducing hardware with higher profiles and wider widths, compared with that for the posterior lumbar interbody fusion (PLIF) approach.

Technique: open lumbar decompression and fusion with the Excelsius GPS robot.

The Excelsius GPS (Globus Medical, Inc.) was approved by the FDA in 2017. This novel robot allows for real-time intraoperative imaging, registration, and direct screw insertion through a rigid external arm-without the need for interspinous clamps or K-wires.

Biomechanical Analysis of an Expandable Lumbar Interbody Spacer.

Objective: Recently developed expandable interbody spacers are widely accepted in spinal surgery; however, the resulting biomechanical effects of their use have not yet been fully studied. We analyzed the biomechanical effects of an expandable polyetheretherketone interbody spacer inserted through a bilateral posterior approach with and without different modalities of posterior augmentation.

Methods: Biomechanical nondestructive flexibility testing was performed in 7 human cadaveric lumbar (L2-L5) specimens followed by axial compressive loading.

Biomechanical Stability Afforded by Unilateral Versus Bilateral Pedicle Screw Fixation with and without Interbody Support Using Lateral Lumbar Interbody Fusion.

Objective: To determine the stability of fusion constructs with unilateral pedicle screw (UPS) or bilateral pedicle screw (BPS) fixation with and without an interbody implant using the lateral lumbar interbody (LLIF) approach.

Methods: Standard nondestructive flexibility tests were performed on 13 cadaveric lumbar specimens to assess spinal stability of intact specimens and 5 configurations of posterior and interbody instrumentation. Spinal stability was determined as mean range of motion in flexion-extension, lateral bending, and axial rotation.