The biomechanical effect of preexisting different types of disc herniation in cervical hyperextension injury.

Objective: Preexisting severe cervical spinal cord compression is a significant risk factor in cervical hyperextension injury, and the neurological function may deteriorate after a slight force to the forehead. There are few biomechanical studies regarding the influence of pathological factors in hyperextension loading condition. The aim of this study is to analyze the effects of preexisting different types of cervical disc herniation and different degrees of compression on the spinal cord in cervical hyperextension.

Effects of contusion load on cervical spinal cord: A finite element study.

Injury of cervical spine is a common injury of locomotor system usually accompanied by spinal cord injury, however the injury mechanism of contusion load to the spinal cord is not clear. This study aims to investigate its injury mechanism associated with the contusion load, with different extents of spinal cord compression. A finite element model of cervical spinal cord was established and two scenarios of contusion injury loading conditions, i.

The Effect of Muscle Direction on the Predictions of Finite Element Model of Human Lumbar Spine.

The normal physiological loads from muscles experienced by the spine are largely unknown due to a lack of data. The aim of this study is to investigate the effects of varying muscle directions on the outcomes predicted from finite element models of human lumbar spine. A nonlinear finite element model of L3-L5 was employed.

Effect of Graded Facetectomy on Lumbar Biomechanics.

Facetectomy is an important intervention for spinal stenosis but may lead to spinal instability. Biomechanical knowledge for facetectomy can be beneficial when deciding whether fusion is necessary. Therefore, the aim of this study was to investigate the biomechanical effect of different grades of facetectomy.

The effects of muscle weakness on degenerative spondylolisthesis: A finite element study.

Background: Whether muscle weakness is a cause, or result, of degenerative spondylolisthesis is not currently well understood. Little biomechanical evidence is available to offer an explanation for the mechanism behind exercise therapy. Therefore, the aim of this study is to investigate the effects of back muscle weakness on degenerative spondylolisthesis and to tease out the biomechanical mechanism of exercise therapy.

Analysis of risk factors for adjacent superior vertebral pedicle-induced facet joint violation during the minimally invasive surgery transforaminal lumbar interbody fusion: a retrospective study.

Background: The purpose was to explore possible risk factors of facet joint violation induced by adjacent superior vertebral pedicle screw during the minimally invasive surgery transforaminal lumbar interbody fusion (MIS-TLIF).

Methods: A total of 69 patients with lumbar degenerative disease, who underwent MIS-TLIF were retrospectively reviewed. Postoperative computed tomography images were used to assess the facet joint violation.

[Efficacy analysis of intermediate screws technique plus injectable calcium sulfate for thoracolumbar fracture in postmenopausal patients].

Objective: To explore the clinical efficacies of intermediate screws plus injectable calcium sulfate MIIGX3 for thoracolumbar fracture in postmenopausal patients.

Methods: A total of 21 postmenopausal patients with vertebral compression fractures reconstructed with posterior internal fixation of intermediate screws technique and anterior vertebral augmentation of MIIGX3 technique in three dimension were retrospectively analyzed. The changes of fracture vertebral height and Cobb's angle were compared.

The strain at bone-implant interface determines the effect of spinopelvic reconstruction following total sacrectomy: a strain gauge analysis in various spinopelvic constructs.

Purpose: There is still some controversy regarding the optimal biomechanical concept for spinopelvic stabilization following total sacrectomy for malignancy. Strains at specific anatomical sites at pelvis/sacrum and implants interfaces have been poorly investigated. Herein, we compared and analyzed the strains applied at key points at the bone-implant interface in four different spinopelvic constructs following total sacrectomy; consequently, we defined a balanced architecture for spinopelvic fusion in that situation.

[Unilateral versus bilateral pedicle fixation at the level of fracture in the treatment of thoracolumbar fractures with mild to moderate instability].

Objective: To evaluate the efficacies of unilateral versus bilateral pedicle screw fixation through the pedicle of fractured vertebra plus short-segment pedicle instrumentation (SSPI) in the treatment of thoracolumbar fractures.

Methods: Between June 2008 and September 2010, a total of 46 patients with fractures of thoracolumbar junction, whose scores of load sharing classification (LSC) ranging from 5 to 7, underwent the combined treatment of SSPI and fracture level pedicle screw at our department. They were divided into 2 groups.

Formative mechanism of intracanal fracture fragments in thoracolumbar burst fractures: a finite element study.

Background: Thoracolumbar burst fracture is a common clinical injury, and the fracture mechanism is still controversial. The aim of this research was to study the formation of intracanal fracture fragments in thoracolumbar burst fractures and to provide information for the prevention of thoracolumbar bursts fractures and reduction of damage to the nervous system.

Methods: A nonlinear three-dimensional finite element model of T11-3 segments was established, and the injury processes of thoracolumbar bursts were simulated.

Pedicle screw fixation for traumatic fractures of the thoracic and lumbar spine.

Background: Spine fractures are common. The treatment of traumatic fractures of the thoracic and lumbar spine remains controversial but surgery involving pedicle screw fixation has become a popular option.

Objectives: To assess the effects (benefits and harms) of pedicle screw fixation for traumatic fractures of the thoracic and lumbar spine.

[Unilateral pedicle screw fixation through the pedicle of fractured vertebra in combination with the short segment of pedicle screw in the treatment of thoracolumbar fracture of mild to moderate instability].

Objective: To evaluate the efficacy of unilateral pedicle screw fixation through the pedicle of fractured vertebra in combination with the short segment of pedicle screw in the treatment of thoracolumbar fracture of mild to moderate instability.

Methods: Twenty-six patients with single segment thoracolumbar fracture received unilateral pedicle screw fixation through the pedicle of fractured vertebra in combination with the short segment of pedicle screw from January 2008 to December 2009. There were 16 patients were male and 10 were female with an average age of 47.

[Building an effective nonlinear three-dimensional finite-element model of human thoracolumbar spine].

Objective: To build an effective nonlinear three-dimensional finite-element (FE) model of T(11)-L(3) segments for a further biomechanical study of thoracolumbar spine.

Methods: The CT (computed tomography) scan images of healthy adult T(11)-L(3) segments were imported into software Simpleware 2.0 to generate a triangular mesh model.