The diagnostic precision of computed tomography for traumatic cervical spine injury: An in vitro biomechanical investigation.

Background: CT is considered the best method for vertebral fracture detection clinically, but its efficacy in laboratory studies is unknown. Therefore, our objective was to determine the sensitivity, precision, and specificity of high-resolution CT imaging compared to detailed anatomic dissection in an axial compression and lateral bending cervical spine biomechanical injury model.

Methods: 35 three-vertebra human cadaver cervical spine specimens were impacted in dynamic axial compression (0.

The effect of end condition on spine segment biomechanics in compression with lateral eccentricity.

During axial impact compression of the cervical spine, injury outcome is highly dependent on initial posture of the spine and the orientation, frictional properties and stiffness of the impact surface. These properties influence the "end condition" the spine experiences in real-world impacts. The effect of end condition on compression and sagittal plane bending in laboratory experiments is well-documented.

The Effect of Compression Applied Through Constrained Lateral Eccentricity on the Failure Mechanics and Flexibility of the Human Cervical Spine.

In contrast to sagittal plane spine biomechanics, little is known about the response of the cervical spine to axial compression with lateral eccentricity of the applied force. This study evaluated the effect of lateral eccentricity on the kinetics, kinematics, canal occlusion, injuries, and flexibility of the cervical spine in translationally constrained axial impacts. Eighteen functional spinal units were subjected to flexibility tests before and after an impact.

A neck compression injury criterion incorporating lateral eccentricity.

There is currently no established injury criterion for the spine in compression with lateral load components despite this load combination commonly contributing to spinal injuries in rollover vehicle crashes, falls and sports. This study aimed to determine an injury criterion and accompanying tolerance values for cervical spine segments in axial compression applied with varying coronal plane eccentricity. Thirty-three human cadaveric functional spinal units were subjected to axial compression at three magnitudes of lateral eccentricity of the applied force.

Shear stiffness in the lower cervical spine: Effect of sequential posterior element injury.

The aim of this study was to determine the effect of the posterior ligaments and facet joints on the shear stiffness of lower cervical functional spinal units in anterior, posterior, and lateral shear. Five functional spinal units were loaded in anterior, posterior, and right lateral shear up to 100 N using a custom-designed apparatus in a materials testing machine. Specimens were tested in three conditions: intact, with the posterior ligaments severed, and with the facet joints removed.

A novel sideways fall simulator to study hip fractures ex vivo.

Falls to the side are the leading cause of hip fractures in the elderly. The load that a person experiences during a fall cannot be measured with volunteers for ethical reasons. To evaluate injurious loads, while considering relevant energy input and body posture for a sideways fall, a subject-specific cadaveric impact experiment was developed.

Damage Identification on Vertebral Bodies During Compressive Loading Using Digital Image Correlation.

Unlabelled: MINI: Identifying fracture is important for understanding vertebral mechanics. Isolated cadaveric thoracolumbar vertebrae were compressed, and surface strains were measured using digital image correlation. Fracture locations from video analysis were qualitatively similar to the locations of high compressive strains and local damage occurred before the maximum force was reached.

Responses of the Acutely Injured Spinal Cord to Vibration that Simulates Transport in Helicopters or Mine-Resistant Ambush-Protected Vehicles.

In the military environment, injured soldiers undergoing medical evacuation via helicopter or mine-resistant ambush-protected vehicle (MRAP) are subjected to vibration and shock inherent to the transport vehicle. We conducted the present study to assess the consequences of such vibration on the acutely injured spinal cord. We used a porcine model of spinal cord injury (SCI).

Defining the inherent stability of degenerative spondylolisthesis: a systematic review.

OBJECT A range of surgical options exists for the treatment of degenerative lumbar spondylolisthesis (DLS). The chosen technique inherently depends on the stability of the DLS. Despite a substantial body of literature dedicated to the outcome analysis of numerous DLS procedures, no consensus has been reached on defining or classifying the disorder with respect to stability or the role that instability should play in a treatment algorithm.

The effect of whole-body resonance vibration in a porcine model of spinal cord injury.

Whole-body vibration has been identified as a potential stressor to spinal cord injury (SCI) patients during pre-hospital transportation. However, the effect that such vibration has on the acutely injured spinal cord is largely unknown, particularly in the frequency domain of 5 Hz in which resonance of the spine occurs. The objective of the study was to investigate the consequences of resonance vibration on the injured spinal cord.

Characterization of the behavior of a novel low-stiffness posterior spinal implant under anterior shear loading on a degenerative spinal model.

Purpose: Dynamic implants have been developed to address potential adjacent level effects due to rigid instrumentation. Rates of revision surgeries may be reduced by using improved implants in the primary surgery. Prior to clinical use, implants should be rigorously tested ex vivo.

The effect of disc degeneration on anterior shear translation in the lumbar spine.

Many pathologies involving disc degeneration are treated with surgery and spinal implants. It is important to understand how the spine behaves mechanically as a function of disc degeneration. Shear loading is especially relevant in the natural and surgically stabilized lumbar spine.

An in vitro model of degenerative lumbar spondylolisthesis.

Study Design: A biomechanical human cadaveric study.

Objective: To create a biomechanical model of low-grade degenerative lumbar spondylolisthesis (DLS), defined by anterior listhesis, for future testing of spinal instrumentation.

Summary Of Background Data: Current spinal implants are used to treat a multitude of conditions that range from herniated discs to degenerative diseases.

Load transfer characteristics between posterior spinal implants and the lumbar spine under anterior shear loading: an in vitro investigation.

Study Design: A biomechanical human cadaveric study.

Objective: To determine the percentage of shear force supported by posterior lumbar spinal devices of varying stiffnesses under anterior shear loading in a degenerative spondylolisthesis model.

Summary Of Background Data: Clinical studies have demonstrated beneficial results of posterior arthrodesis for the treatment of degenerative spinal conditions with instability.

Shear force measurements on low- and high-stiffness posterior fusion devices.

Low-stiffness posterior fusion devices for the lumbar spine have been developed to treat degenerative spinal conditions. However, the demands on an implant vary between a stable motion segment and one which exhibits a significant degree of sagittal plane instability. Shear motion in the antero-posterior direction is a relevant mode of instability for clinical conditions such as degenerative lumbar spondylolisthesis.

Pediatric and adult three-dimensional cervical spine kinematics: effect of age and sex through overall motion.

Study Design: Cross-sectional study.

Objective: To determine the effect of age and sex on the three-dimensional kinematics of the cervical spine.

Summary Of Background Data: Spine kinematics information has important implications for biomechanical model development, anthropomorphic test device development, injury prevention, surgical treatment, and safety equipment design.