The spine journal : official journal of the North American Spine Society
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Comparative Study
Presurgical biopsychosocial factors predict multidimensional patient: outcomes of interbody cage lumbar fusion.
Interbody cage lumbar fusion (ICLF) has been advanced to improve arthrodesis; however, little attention has been given to quality of life and functional outcomes. Studies suggest that psychosocial factors may be important modifiers of low back surgical outcomes. ⋯ Overall, despite a high rate of arthrodesis, ICLF was not associated with substantial improvements in patient functioning. Presurgical biopsychosocial variables predicted patient outcomes, which may help improve patient selection and possible targeted interventions.
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Comparative Study
Biomechanical changes after the augmentation of experimental osteoporotic vertebral compression fractures in the cadaveric thoracic spine.
Osteoporotic compression fractures are an important public health concern, leading to significant morbidity, mortality and economic burden. Cement augmentation procedures used to treat these fractures alter the biomechanics of the fractured segment, which could promote adjacent failure. However, if alignment is improved or restored, there will be less risk of adjacent failure. ⋯ With axial compressive loads, the addition of flexion increases fracture risk. Cement augmentation of a fractured vertebral segment reduces stiffness while increasing both the superior and inferior adjacent cortical strain. This increment in strain that is greatest on the inferior adjacent vertebra effectively redistributes loads from the superior adjacent vertebra to the inferior adjacent vertebra, sparing the superior adjacent vertebra from failure.
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Comparative Study
The effect of uniform heating on the biomechanical properties of the intervertebral disc in a porcine model.
The use of minimally invasive lumbar intradiscal heating techniques, including intradiscal electro-thermal therapy (IDET), endoscopic radio-frequency annuloplasty, nucleoplasty and laser discectomy, for chronic lumbar discogenic pain and contained disc herniation has recently gained popularity. The purported therapeutic mechanisms of these interventions include subtotal nuclectomy, annular nociceptor ablation, and stabilization of the annular fibers. Basic science data elucidating the biomechanical and histomorphologic alterations of heat treatments on disc remain sparse. ⋯ The application of uniform heating to nucleus pulposus disc core caused visible contraction of its circumference but not lengthwise shrinkage. The same heating shrinks the hamstring tendon and reduces its stiffness. Ultimate failure strength of the disc core specimen remains unchanged. The failure data was not obtainable for the tendon due to premature slippage from the fixation apparatus before failure. The results of this study fail to support a biomechanical justification for the application of uniform heat treatment to the whole intervertebral disc. Heating annulus fibrosus and nucleus pulposus separately to specific temperatures may have potential clinical benefits.
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Case Reports
Image-guided surgery in resection of benign cervicothoracic spinal tumors: a report of two cases.
Osseous spinal tumors are an uncommon cause of persistent axial pain and muscle spasm, but even benign lesions may grow to cause deformity or neurological signs. Traditional treatment approaches to resection can be debilitating even when the tumor is benign. ⋯ Image guidance can accurately localize and guide excision of benign vertebral lesions while minimizing soft tissue trauma and collateral damage, allowing patients a rapid and complete return to high-demand function.
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Comparative Study
Quantitative analysis of gene expression in a rabbit model of intervertebral disc degeneration by real-time polymerase chain reaction.
Serial analysis of gene expression during the course of intervertebral disc degeneration (IDD) could elucidate valuable insight into pathophysiology and provide a basis for identification of potential targets for the development of novel cellular- and gene-based therapies. However, very few previous studies described the changes in gene expression through the process of IDD using a suitable animal model. ⋯ The gene expression profiles of ECM components and anabolic, catabolic, and anti-catabolic factors demonstrate many characteristics similar to the findings in human disc degeneration and suggest an inability of the intervertebral disc (IVD) to mount an early anabolic response to injury, thereby offering a possible explanation for the disc's lack of reparative capabilities. Catabolic genes are strongly up-regulated both early and late in degeneration, lending strong support to the hypothesis that an anabolic or catabolic imbalance plays a primary role in IDD. According to the resultant patterns, augmenting early production of BMP-2, BMP-7, IGF-1 or TIMP-1 by gene transfer techniques might possibly alter the progressive course of degeneration as seen in the stab model. The next step will be to transfer these therapeutic genes to regulate the biologic processes and ideally alter the progressive course of disc degeneration.