Role of Epiligament in Ligamentum Flavum Hypertrophy in Patients with Lumbar Spinal Canal Stenosis:a Pilot Study.

Ligamentum flavum (LF) hypertrophy is one of the main factors of lumbar spinal canal stenosis (LSCS). The primary object of this study is to clarify the existence of epiligament in the LF and its role in hypertrophy, and to develop an LF hypertrophy animal model. A cadaveric spine from a 30-year-old man was used to investigate the existence of epiligament in LF.

Adjacent level effects of bi level disc replacement, bi level fusion and disc replacement plus fusion in cervical spine--a finite element based study.

Background: Studies delineating the adjacent level effect of single level disc replacement systems have been reported in literature. The aim of this study was to compare the adjacent level biomechanics of bi-level disc replacement, bi-level fusion and a construct having adjoining level disc replacement and fusion system.

Methods: In total, biomechanics of four models- intact, bi level disc replacement, bi level fusion and fusion plus disc replacement at adjoining levels- was studied to gain insight into the effects of various instrumentation systems on cranial and caudal adjacent levels using finite element analysis (73.

Biomechanical rationale of sacral rounding deformity in pediatric spondylolisthesis: a clinical and biomechanical study.

Aim: Rounding surface of the sacral dome and wedging deformity of the vertebral body are commonly observed in patients with isthmic spondylolisthesis. Recently, an animal study showed that the deformity can be caused by the growth plate involvement in the immature pediatric vertebral body after biomechanical alteration due to the pars defects. However, the pathomechanism and biomechanics of these deformities have yet to be clarified.

A retrospective analysis of patient perceived outcomes in patients 55 years and older undergoing anterior cervical discectomy and fusion.

Study Design/setting: Retrospective review of clinical outcomes after anterior cervical discectomy and fusion (ACDF) surgery with allograft and plating in patients over 55 years of age.

Objective: To evaluate the results of ACDF surgery in patients aged 55 years and older.

Summary Of Background Data: ACDF surgery has been a standard treatment for cervical degenerative and herniated disc disease for many years.

Do design variations in the artificial disc influence cervical spine biomechanics? A finite element investigation.

Various ball and socket-type designs of cervical artificial discs are in use or under investigation. Many artificial disc designs claim to restore the normal kinematics of the cervical spine. What differentiates one type of design from another design is currently not well understood.

Newly occurred L4 spondylolysis in the lumbar spine with pre-existence L5 spondylolysis among sports players: case reports and biomechanical analysis.

Study Design: Case series and a biomechanical study using a finite element (FE) analysis.

Objectives: To report three cases with multi-level spondylolysis and to understand the mechanism biomechanically.

Background: Multi-level spondylolysis is a very rare condition.

Cervical spondylolysis in a judo player: a case report and biomechanical analysis.

Study Design: A case report and a biomechanical study using a finite element method.

Objectives: To report a case with the cervical spondylolysis and to understand the biomechanics of the cervical spine with spondylolysis at C6. Cervical spondylolysis, although not a common spinal disorder, can occur in athletes.

Pathomechanism of loss of elasticity and hypertrophy of lumbar ligamentum flavum in elderly patients with lumbar spinal canal stenosis.

Study Design: A histologic, biologic, and immunohistochemical assessment using human samples of lumbar ligamentum flavum.

Objective: To clarify the pathomechanism of loss of elasticity and hypertrophy of the lumbar ligamentum flavum (LF) in the elderly population.

Summary Of Background Data: The most common spinal disorder in elderly patients is lumbar spinal canal stenosis, causing low back and leg pain, and paresis.

Biomechanical rationale of ossification of the secondary ossification center on apophyseal bony ring fracture: a biomechanical study.

Background: Apophyseal ring fracture is one of the important pathologies causing low back pain in children and adolescents. Most of the patients are reported to be in the ossification stage of the ring during growth period rather than early cartilaginous ring stage. There is no previous study clarifying the mechanism of the high prevalence of this disorder in the ossification stage.

Lumbar ligamentum flavum hypertrophy is due to accumulation of inflammation-related scar tissue.

Study Design: A histologic, biologic, and immunohistochemical assessment using human samples of the lumbar ligamentum flavum.

Objective: To prove our hypothesis that hypertrophy of the ligamentum flavum is caused by accumulation of inflammation-related scar tissue.

Summary Of Background Data: Lumbar spinal canal stenosis is 1 of the most common spinal disorders in elderly patients.

Biomechanical rationale for using polyetheretherketone (PEEK) spacers for lumbar interbody fusion-A finite element study.

Study Design: To determine the effect of cage/spacer stiffness on the stresses in the bone graft and cage subsidence.

Objective: To investigate the effect of cage stiffness on the biomechanics of the fused segment in the lumbar region using finite element analysis.

Summary Of Background Data: There are a wide variety of cage/spacer designs available for lumbar interbody fusion surgery.

Biomechanics of two-level Charité artificial disc placement in comparison to fusion plus single-level disc placement combination.

Background Context: Biomechanical studies of artificial discs that quantify parameters such as load sharing and stresses have been reported in literature for single-level disc placements. However, literature on the effects of using the Charité artificial disc (ChD) at two levels (2LChD) as compared with one-level fusion (using a cage [CG] and a pedicle screw system) plus one-level artificial disc combination (CGChD) is sparse.

Purpose: To determine the effects of the 2LChD and CGChD across the implanted and adjacent segments.

Effect of lumbar interbody cage geometry on construct stability: a cadaveric study.

Study Design: Biomechanical study to investigate three-dimensional motion behavior of cadaveric spines in various surgical simulations.

Objectives: To determine the effect of cage geometry on the construct stability.

Summary Of Background Data: There is a wide variety of cage/spacer designs available for lumbar interbody fusion surgery.

Three-dimensional finite element analysis of the pediatric lumbar spine. Part I: pathomechanism of apophyseal bony ring fracture.

The purpose of this study was to (1) develop a three-dimensional, nonlinear pediatric lumbar spine finite element model (FEM), and (2) identify the mechanical reasons for the posterior apophyseal bony ring fracture in the pediatric patients. The pediatric spine FE model was created from an experimentally validated three-dimensional adult lumbar spine FEM. The size of the FEM was reduced to 96% taking into account of the ratio of the sitting height of an average 14-years-old children to that of an adult.

Three dimensional finite element analysis of the pediatric lumbar spine. Part II: biomechanical change as the initiating factor for pediatric isthmic spondylolisthesis at the growth plate.

A non-linear 3-dimensional finite element pediatric lumbar spine model with vertebral growth plate and apophyseal bony ring was developed. Lumbar spondylolysis was simulated in the model. The Von Mises stresses in the structures surrounding the vertebral growth plate, including apophyseal bony ring and osseous endplate were calculated in various loading modes.

Effect of the increase in the height of lumbar disc space on facet joint articulation area in sagittal plane.

Study Design: Computerized tomography (CT) of the lumbar spine cadaveric specimens was used to evaluate the effect of increasing the height of the disc space in the lumbar spine to the facet joint articulation in the sagittal plane.

Objective: To show how the facet joint articulation is affected by increasing the height of the disc space in the lumbar spine.

Summary Of Background Data: The Charité Artificial Disc (DePuy Spine, Inc.

MRI signal changes of the pedicle as an indicator for early diagnosis of spondylolysis in children and adolescents: a clinical and biomechanical study.

Study Design: Clinical review of pediatric patients with lumbar spondylolysis and biomechanical analysis using finite-element lumbar spine model.

Objectives: To evaluate the usefulness of the signal changes observed on MR images of the pedicle for the early diagnosis of spondylolysis, and to investigate the pathomechanism of the signal changes based on the stresses in pedicles, as predicted using finite-element analyses. Furthermore, to evaluate the usefulness of the signal change to predict the bony healing following conservative treatment.

Effects of charité artificial disc on the implanted and adjacent spinal segments mechanics using a hybrid testing protocol.

Study Design: Finite element model of L3-S1 segment and confirmatory cadaveric testing were used to investigate the biomechanical effects of a mobile core type artificial disc (Charité artificial disc; DePuy Spine, Raynham, MA) on the lumbar spine.

Objective: To determine the effects of the Charité artificial disc across the implanted and adjacent segments.

Summary Of Background Data: Biomechanical studies of artificial discs that quantify parameters, like the load sharing and stresses, are sparse in the literature, especially for mobile-type core artificial disc designs.

Pathomechanism of ligamentum flavum hypertrophy: a multidisciplinary investigation based on clinical, biomechanical, histologic, and biologic assessments.

Study Design: A multidisciplinary study involving clinical, histologic, biomechanical, biologic, and immunohistologic approaches. OBJECTIVE.: To clarify the pathomechanism of hypertrophy of the ligamentum flavum.

Athletes with unilateral spondylolysis are at risk of stress fracture at the contralateral pedicle and pars interarticularis: a clinical and biomechanical study.

Background: Unilateral spondylolysis is common in youths; its clinical and biomechanical features, especially effects on the contralateral side, are not fully understood.

Hypothesis: Unilateral spondylolysis predisposes the contralateral side to stress fracture, especially in athletes actively engaged in sporting activities involving torsion of the trunk.

Study Design: Case series and descriptive laboratory study.

Low back pain: pathophysiology and management.

Basic research is advancing the understanding of the pathogenesis and management of low back pain at the molecular and genetic levels. Frequently, low back pain is caused by disorders of the intervertebral disk. Cytokines such as matrix metalloproteinases, phospholipase A2, nitric oxide, and tumor necrosis factor-alpha are thought to contribute to the development of low back pain.

Intradiscal electrothermal therapy: a treatment option in patients with internal disc disruption.

Study Design: A literature review was conducted.

Objectives: To review the anatomy, pathophysiology, diagnosis, procedure, and clinical results of intradiscal electrothermal therapy (IDET).

Summary Of Background Data: Low back pain is a major physical and socioeconomic entity.

Effects of slip severity and loading directions on the stability of isthmic spondylolisthesis: a finite element model study.

Study Design: Using a validated finite element model, the biomechanical effects of pars defect in a lumbar segment with and without different degrees of slip (up to 50% slip) were studied.

Objectives: To study the effects of slip severity and loading parameters on the stability of the lytic and adjacent motion segments. Better knowledge of the biomechanics of spondylolisthesis may help formulate treatment strategies such as bracing or spinal implants.

Percutaneous computed tomographic stabilization of the pathologic sacroiliac joint.

Metastases to the sacroiliac joint region can be a source of significant pain in many patients who are terminally ill. Six patients with metastatic lesions in the sacroiliac region who presented with significant posterior pelvic pain were treated with computed tomography-guided insertion of iliosacral screws. All patients reported excellent pain control in the early postoperative period.