Pediatric High-Risk Conditions.

Meningitis, appendicitis, and testicular torsion are among the most common conditions resulting in malpractice litigation in Pediatric Emergency Medicine. With meningitis, most litigation claims involved patients <2 years old. Notably, 25% of patients had no fever and many lacked classic signs of meningitis.

Neurogenic Pulmonary Edema Associated with Hyponatremia, Primary Polydipsia, and Cannabis Use: A Case Report.

Introduction: Neurogenic pulmonary edema is a rare and potentially life-threatening condition that can present as severe pulmonary edema after significant neurologic insults. This is the first documented instance that shows a plausible causal link between cannabis consumption, psychogenic polydipsia, and the subsequent development of neurogenic pulmonary edema associated with status epilepticus secondary to acute hyponatremia.

Case Report: We report a case of a 34-year-old female who presented to the emergency department altered and postictal after a witnessed new-onset seizure.

Do early stages of lumbar intervertebral disc degeneration really cause instability? Evaluation of an in vitro database.

Early stages of intervertebral disc degeneration are postulated to cause instability. In the literature, however, some authors report the opposite. These contradictory positions are probably supported by the mostly small number of segments which are investigated.

Influence of the loading frequency on the wear rate of a polyethylene-on-metal lumbar intervertebral disc replacement.

Pre-clinical wear testing of intervertebral disc prostheses is commonly carried out according to ISO 18192-1. Ten million multiaxial loading cycles are applied at a frequency of 1 Hz. At this frequency, testing takes about 4 months.

[Biomechanics of interspinous spacers].

Interspinous spacers are commonly used to treat lumbar spinal stenosis or facet joint arthritis. The aims of implanting interspinous devices are to unload the facet joints, restore foraminal height, and provide stability especially in extension but still allow motion. This paper summarizes several in vitro studies, which compared four different interspinous implants - Coflex, Wallis, DIAM, and X-STOP - in terms of their three-dimensional primary stability, the intradiscal pressure, and stability after cyclic loading.

Biomechanical effect of different lumbar interspinous implants on flexibility and intradiscal pressure.

Interspinous implants are used to treat lumbar spinal stenosis or facet joint arthritis. The aims of implanting interspinous devices are to unload the facet joints, restore foraminal height and provide stability especially in extension but still allow motion. The aim of this in vitro study was to compare four different interspinous implants--Colfex, Wallis, Diam and X-Stop--in terms of their three-dimensional flexibility and the intradiscal pressure.

Can a modified interspinous spacer prevent instability in axial rotation and lateral bending? A biomechanical in vitro study resulting in a new idea.

Background: Interspinous spacers are mainly used to treat lumbar spinal stenosis and facet arthrosis. Biomechanically, they stabilise in extension but do not compensate instability in axial rotation and lateral bending. It would therefore be desirable to have an interspinous spacer available, which provides for more stability also in these two planes.

The risk of disc prolapses with complex loading in different degrees of disc degeneration - a finite element analysis.

Background: Disc prolapses can result from various complex load situations and degenerative changes in the intervertebral disc. The aim of this finite element study was to find load combinations that would lead to the highest internal stresses in a healthy and in degenerated discs.

Methods: A three-dimensional finite element model of a lumbar spinal segment L4-L5 in different grades of disc degeneration (healthy, mild, moderate, and severe) were generated, in which the disc height reduction, the formation of osteophytes and the increasing of nucleus' compressibility were considered.

Are the spines of calf, pig and sheep suitable models for pre-clinical implant tests?

Pre-clinical in vitro tests are needed to evaluate the biomechanical performance of new spinal implants. For such experiments large animal models are frequently used. Whether these models allow any conclusions concerning the implant's performance in humans is difficult to answer.

Are animal models useful for studying human disc disorders/degeneration?

Intervertebral disc (IVD) degeneration is an often investigated pathophysiological condition because of its implication in causing low back pain. As human material for such studies is difficult to obtain because of ethical and government regulatory restriction, animal tissue, organs and in vivo models have often been used for this purpose. However, there are many differences in cell population, tissue composition, disc and spine anatomy, development, physiology and mechanical properties, between animal species and human.

Morphological changes of cervical facet joints in elderly individuals.

To better understand the role of facet joint degeneration in chronic neck and back pain epidemiological and morphological data are needed. For the cervical spine, however, such data are rare. Therefore, the aim of this study was to determine the degree of cartilage degeneration of cervical facet joints with respect to spinal level and age, to investigate whether any region of the joint surface is more often affected by degeneration and to determine the localisation of osteophytes.

Intradiscal pressure, shear strain, and fiber strain in the intervertebral disc under combined loading.

Study Design: Finite element study.

Objective: To investigate intradiscal pressure, shear strain between anulus and adjacent endplates, and fiber strain in the anulus under pure and combined moments.

Summary Of Background Data: Concerning anulus failures such as fissures and disc prolapses, the mechanical response of the intervertebral disc during combined load situations is still not well understood.

In vitro study of biomechanical behavior of anterior and transforaminal lumbar interbody instrumentation techniques.

Objective: To study the biomechanical behavior of lumbar interbody instrumentation techniques using titanium cages as either transforaminal lumbar interbody fusion (TLIF) or anterior lumbar interbody fusion (ALIF), with and without posterior pedicle fixation.

Methods: Six fresh-frozen lumbar spines (L1-L5) were loaded with pure moments of +/-7.5 Nm in unconstrained flexion-extension, lateral bending, and axial rotation.

Cervical spine disc prosthesis: radiographic, biomechanical and morphological post mortal findings 12 weeks after implantation. A retrieval example.

There is a gap between in vitro and clinical studies concerning performance of spinal disc prosthesis. Retrieval studies may help to bridge this gap by providing more detailed information about motion characteristics, wear properties and osseous integration. Here, we report on the radiographic, mechanical, histological properties of a cervical spine segment treated with a cervical spine disc prosthesis (Prodisc C, Synthes Spine, Paoli, USA) for 3 months.

Biomechanical behavior of a new nucleus prosthesis made of knitted titanium filaments.

Background: One of the greatest challenges in the development of a nucleus prosthesis is to minimize the risk of implant expulsion. At the same time, the physiological flexibility, compressive behavior, and height of the disc should be restored. In this biomechanical in vitro study we investigated the ability of a new nucleus prosthesis made of knitted titanium filaments to meet these challenges.

Validity and interobserver agreement of a new radiographic grading system for intervertebral disc degeneration: Part II. Cervical spine.

A new radiographic grading system for a more objective assessment of lumbar intervertebral disc degeneration has been described and tested in Part I of this study. The aim of the present Part II of the study was to adapt this system to the cervical spine, and to test it for validity and interobserver agreement. Some modifications of the grading system described in Part I were necessary to make it applicable to the cervical spine.

Biomechanical performance of the new BeadEx implant in the treatment of osteoporotic vertebral body compression fractures: restoration and maintenance of height and stability.

Background: Vertebral compression fractures are counted among the most common complications of osteoporosis. For treatment, a new, alternative implant has been developed (BeadEx, Expandis, Hof HaCarmel, Israel). The aim of the present in vitro study was to evaluate whether this implant is able to restore the initial height and three-dimensional stability after fracture and whether it is able to maintain this height and stability during complex cyclic loading.

In vitro fixator rod loading after transforaminal compared to anterior lumbar interbody fusion.

Background: Cages are commonly used to assist lumbar interbody fusion. They are implanted from various approaches. In many cases internal fixators are added to provide sufficient stability.

Application of a new calibration method for a three-dimensional finite element model of a human lumbar annulus fibrosus.

Background: Major deficits of many finite element models of the lumbar spine are the oversimplification, assumed constellation of the material properties or the insufficiently performed calibration using experimental in vitro data. The aim of this study was, to develop a method for calibrating the two-composite structure of the annulus fibrosus, the ground substance and collagen fibers.

Methods: For that purpose, a three-dimensional, non-linear finite element model of a denucleated intervertebral disc with the adjacent vertebral bodies (L4-L5) was created.

Validity and interobserver agreement of a new radiographic grading system for intervertebral disc degeneration: Part I. Lumbar spine.

Many different radiographic grading systems for disc degeneration are described in literature. However, only a few of them are tested for interobserver agreement and none for validity. Furthermore, most of them are based on a subjective terminology.

Influence of the crash pulse shape on the peak loading and the injury tolerance levels of the neck in in vitro low-speed side-collisions.

The aim of the present in vitro study was to investigate the effect of the crash pulse shape on the peak loading and the injury tolerance levels of the human neck. In a custom-made acceleration apparatus 12 human cadaveric cervical spine specimens, equipped with a dummy head, were subjected to a series of incremental side accelerations. While the duration of the acceleration pulse of the sled was kept constant at 120 ms, its shape was varied: Six specimens were loaded with a slowly increasing pulse, i.

In vitro stabilizing effect of a transforaminal compared with two posterior lumbar interbody fusion cages.

Study Design: An in vitro biomechanical flexibility test on different lumbar interbody fusion cages using monosegmental lumbar spine specimens.

Objective: To investigate the stabilizing effect of a transforaminal lumbar interbody fusion (TLIF) cage compared with two established posterior lumbar interbody fusion (PLIF) cages.

Summary Of Background Data: TLIF using interbody fusion cages is gaining more and more popularity in the treatment of degenerative disc disease.

Review of existing grading systems for cervical or lumbar disc and facet joint degeneration.

The aim of this literature review was to present and to evaluate all grading systems for cervical and lumbar disc and facet joint degeneration, which are accessible from the MEDLINE database. A MEDLINE search was conducted to select all articles presenting own grading systems for cervical or lumbar disc or facet joint degeneration. To give an overview, these grading systems were listed systematically depending on the spinal region they refer to and the methodology used for grading.

[Accident analytics for structural traumas of the cervical spine].

The differentiation between degenerative syndromes of the cervical spine and post-traumatic symptoms requires accident analysis. Experiments with human subjects yield data only in the low-energy range, and there are still no accident analyses of structural traumas of the cervical spine. From 1 January 2000 to 30 April 2002, 15 patients with structural injuries to the cervical spine due to car accidents were treated in the Department of Trauma Surgery of the University of Ulm.

Correlation between neck injury risk and impact severity parameters in low-speed side collisions.

Study Design: In vitro acceleration study on human cadaveric cervical spine specimens.

Objectives: To investigate the correlation between the risk to sustain a structural cervical spine injury and vehicle-related impact severity parameters.

Summary Of Background Data: Impact severity parameters, such as the peak acceleration of the vehicle, its mean acceleration, and its velocity change, are often used to predict the whiplash injury risk or to objectify the patient's symptoms even though their correlation to injury is still not well understood.