Spine
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A finite-element study of posterior alone or anterior/posterior combined instrumentation following total spondylectomy and replacement with a titanium mesh cage used as an anterior strut. ⋯ This experiment shows that from the viewpoint of stress shielding, the reconstruction method, using additional anterior instrumentation with posterior pedicle screws (MPAI and SPAI), stress shields the cancellous bone inside the titanium mesh cage to a higher degree than does the system using posterior pedicle screw fixation alone (MPI). Thus, a reconstruction method with no anterior fixation should be better at allowing stress for remodeling of the bone graft inside the titanium mesh cage.
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Comparative Study
Biomechanical changes at adjacent segments following anterior lumbar interbody fusion using tapered cages.
A biomechanical evaluation of anterior cages in a calf lumbar spine model. ⋯ Statistically significant changes in intradiscal pressures and motion were found at the adjacent levels following a single-level stand-alone ALIF procedure using paired LT cages.
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Lower lumbar vertebral endplates from young and old sand rats were assessed in an Institutional Animal Care and Use Committee approved study for architectural endplate features using micro-computerized tomography (CT) 3-dimensional (3D) models and vascularization studies by an in vivo vascular tracer or immunocytochemical identification of blood vessels. ⋯ Findings show that disc degeneration in the sand rat occurs concomitantly with marked architectural bony changes on the endplate face, including loss of smoothness and development of irregular bony margins. Vascular connections were not present between the endplate and disc; this was verified with microCT studies, in vivo vascular tracers, and traditional immunocytochemistry. The canal system within the imaged endplate was revealed to consist of a complex 3D interconnected network.
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Review Comparative Study
Transcutaneous electrical nerve stimulation for the treatment of chronic low back pain: a systematic review.
Systematic review. ⋯ Evidence for the efficacy of TENS as an isolated intervention in the management of chronic LBP is limited and inconsistent. Larger, multicenter, RCTs are needed to better resolve its role in this condition. Increased attention should be given to the risks and benefits of long-term use, which more appropriately addresses the realities of managing chronic low back pain.
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Comparative Study
Pathomechanism of ligamentum flavum hypertrophy: a multidisciplinary investigation based on clinical, biomechanical, histologic, and biologic assessments.
A multidisciplinary study involving clinical, histologic, biomechanical, biologic, and immunohistologic approaches. OBJECTIVE.: To clarify the pathomechanism of hypertrophy of the ligamentum flavum. ⋯ Fibrosis is the main cause of ligamentum flavum hypertrophy, and fibrosis is caused by the accumulation of mechanical stress with the aging process, especially along the dorsal aspect of the ligamentum flavum. TGF-beta released by the endothelial cells may stimulate fibrosis, especially during the early phase of hypertrophy.