BACKGROUND Many decompression procedures involve complete or partial facetectomy. Spinal fusion usually stabilizes the motion segment after complete facetectomies. However, problems with fusion, such as adjacent-level degeneration, have increased interest in motion- preservation technologies. Facet arthroplasty may become an important posterior motion-preservation device, but its biomechanical ...

Previous work on the expression of bovine opsin fragments separated in the cytoplasmic region has allowed the identification of specific polypeptide segments that contain sufficient information to fold independently, insert into a membrane, and assemble to form a functional photoreceptor. To further examine the contributions of these and other polypeptide segments to the mechanism of opsin fold...

OBJECTIVE The purpose of this study is to investigate the incidence of new compression and to analyze factors that influence the fractures in adjacent levels after percutaneous vertebroplasty (PVP). METHODS This retrospective study examined 206 patients who had undergone PVP for single level osteoporotic or osteopenic compression fractures during the last seven years in our department. After ...

To investigate the role of different cysteine residues in bovine rhodopsin, a series of mutants were prepared in which the cysteine residues were systematically replaced by serines. The mutant genes were expressed in monkey kidney cells (COS-1) and the mutant opsins were evaluated for their levels of expression, glycosylation patterns, and ability to form the chromophore characteristic of rhodo...

INTRODUCTION: Intervertebral disc (IVD) degeneration is an important clinical problem that often contributes to low back pain and degenerative disc diseases. Degeneration of the IVD induces anulus tears and fissures, which can cause severe discogenic low back pain. Because the IVD has little potential to self-regenerate, treatment of degenerative disc disease is one of the most challenging clin...

Lumbar spine degeneration diseases require precise prediction of biomechanical parameters. These parameters include stress in ligaments, intradiscal pressure and facet loads. For this purpose, several symmetrical FE models of lumbar spine have been proposed previously with inherent simplifications in design. Such models may not give realistic results for biomechanical analysis because of the as...

OBJECTIVES To compare the influence of posterior lumbar interbody fusion (PLIF) and transforaminal lumbar interbody fusion (TLIF) on adjacent segment degeneration (ASD). METHODS The study was carried out in the Traumatology and Orthopedics Laboratory, Department of Traditional Chinese Medicine, Medical School, Jinan University, Guangzhou, China, between December 2013 and November 2014. A norm...

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. The force of the erector spinae muscle, the force of the rectus abdomini...

The present study was conducted to examine the effects of body weight on intradiscal pressure (IDP) and annulus stress of intervertebral discs at lumbar spine. Three-dimensional finite element model of osseoligamentous lumbar spine was developed subjected to follower load of 500 N, 800 N, and 1200 N which represent the loads for individuals who are normal and overweight with the pure moments at...

The main purpose of this study was to investigate the compensatory response of the muscle activities of seventeen major muscle groups in the spinal region, intradiscal forces of the five lumbar motion segment units (MSUs), and facet forces acting on the ten lumbar facet joints in patients with lumbar disc herniation (LDH). Twenty-six healthy adults and seven LDH patients performed trunk flexion...