Upper Cervical Spine Loading Simulating a Dynamic Low-Speed Collision Significantly Increases the Risk of Pain Compared to Quasi-Static Loading With Equivalent Neck Kinematics.

Dynamic cervical spine loading can produce facet capsule injury. Despite a large proportion of neck pain being attributable to the C2/C3 facet capsule, potential mechanisms are not understood. This study replicated low-speed frontal and rear-end traffic collisions in occiput-C3 human cadaveric cervical spine specimens and used kinematic and full-field strain analyses to assess injury.

Relevant Anatomic and Morphological Measurements of the Rat Spine: Considerations for Rodent Models of Human Spine Trauma.

Study Design: Basic science study measuring anatomical features of the cervical and lumbar spine in rat with normalized comparison with the human.

Objective: The goal of this study is to comprehensively compare the rat and human cervical and lumbar spines to investigate whether the rat is an appropriate model for spine biomechanics investigations.

Summary Of Background Data: Animal models have been used for a long time to investigate the effects of trauma, degenerative changes, and mechanical loading on the structure and function of the spine.

Whole-body Vibration at Thoracic Resonance Induces Sustained Pain and Widespread Cervical Neuroinflammation in the Rat.

Background: Whole-body vibration (WBV) is associated with back and neck pain in military personnel and civilians. However, the role of vibration frequency and the physiological mechanisms involved in pain symptoms are unknown.

Questions/purposes: This study asked the following questions: (1) What is the resonance frequency of the rat spine for WBV along the spinal axis, and how does frequency of WBV alter the extent of spinal compression/extension? (2) Does a single WBV exposure at resonance induce pain that is sustained? (3) Does WBV at resonance alter the protein kinase C epsilon (PKCε) response in the dorsal root ganglia (DRG)? (4) Does WBV at resonance alter expression of calcitonin gene-related peptide (CGRP) in the spinal dorsal horn? (5) Does WBV at resonance alter the spinal neuroimmune responses that regulate pain?

Methods: Resonance of the rat (410 ± 34 g, n = 9) was measured by imposing WBV at frequencies from 3 to 15 Hz.

Kinematic magnetic resonance imaging to define the cervical facet joint space for the spine in neutral and torsion.

Study Design: Prospectively acquire magnetic resonance images of the neck in normal subjects and patients with radiculopathy to measure and compare measures of the facet joint space thickness and volume.

Objective: The goal was to determine whether there is any difference in facet joint architecture between the 2 populations with the head in each of neutral and pain-eliciting rotation.

Summary Of Background Data: Degeneration and altered mechanics of the facet joint can result in pathological nerve root compression and pain.

ProDisc cervical arthroplasty does not alter facet joint contact pressure during lateral bending or axial torsion.

Study Design: A biomechanical study of facet joint pressure after total disc replacement using cadaveric human cervical spines during lateral bending and axial torsion.

Objective: The goal was to measure the contact pressure in the facet joint in cadaveric human cervical spines subjected to physiologic lateral bending and axial torsion before and after implantation of a ProDisc-C implant.

Summary Of Background Data: Changes in facet biomechanics can damage the articular cartilage in the joint, potentially leading to degeneration and painful arthritis.

Facet joint contact pressure is not significantly affected by ProDisc cervical disc arthroplasty in sagittal bending: a single-level cadaveric study.

Background Context: Total disc arthroplasty is a motion-preserving spinal procedure that has been investigated for its impact on spinal motions and adjacent-level degeneration. However, the effects of disc arthroplasty on facet joint biomechanics remain undefined despite the critical role of these posterior elements on guiding and limiting spinal motion.

Purpose: The goal was to measure the pressure in the facet joint in cadaveric human cervical spines subjected to sagittal bending before and after implantation of the ProDisc-C (Synthes Spine Company, L.

Spinal facet joint biomechanics and mechanotransduction in normal, injury and degenerative conditions.

The facet joint is a crucial anatomic region of the spine owing to its biomechanical role in facilitating articulation of the vertebrae of the spinal column. It is a diarthrodial joint with opposing articular cartilage surfaces that provide a low friction environment and a ligamentous capsule that encloses the joint space. Together with the disc, the bilateral facet joints transfer loads and guide and constrain motions in the spine due to their geometry and mechanical function.

Contact pressure in the facet joint during sagittal bending of the cadaveric cervical spine.

The facet joint contributes to the normal biomechanical function of the spine by transmitting loads and limiting motions via articular contact. However, little is known about the contact pressure response for this joint. Such information can provide a quantitative measure of the facet joint's local environment.

Pressure measurement in the cervical spinal facet joint: considerations for maintaining joint anatomy and an intact capsule.

Study Design: A novel noninvasive approach to measure facet joint pressure in the cervical spine was investigated using a tip-mounted transducer that can be inserted through a hole in the bony lateral mass. This technique is advantageous because it does not require resection of the joint capsule, but there are potential issues regarding its applicability that are addressed.

Objective: The objective was to evaluate the effect of a tip-mounted pressure probe's position and orientation on contact pressure measurements in biomechanical experiments.