Spine
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Comparative Study
Immediate biomechanical effects of lumbar posterior dynamic stabilization above a circumferential fusion.
Biomechanical in vitro human cadaveric lumbar flexibility testing with 6 sequential treatments. ⋯ ROM at the superior adjacent level (L2-L3) demonstrated no significant difference between intact, destabilized, one-level posterior fixation, and one-level circumferential fusion at the index level (L3-L4) when comparing posterior dynamic stabilization to rigid rod fixation. However, ROM at the superior adjacent level (L2-L3) was significantly greater for lateral bending and axial rotation when both levels (L2-L3 and L3-L4) were stabilized with a dynamic stabilization system. When the functional spinal units were instrumented with a two-level hybrid construct, two-level posterior instrumentation (L2-L3 and L3-L4) with a cage at the index level (L3-L4), all bending modes generated significantly greater ROM for the dynamic stabilization group at L2-L3 compared with rigid rod fixation.
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Comparative Study
Aggrecanases and aggrecanase-generated fragments in the human intervertebral disc at early and advanced stages of disc degeneration.
A comparative study of aggrecanases and aggrecan fragmentation profile in the human intervertebral disc at early and advanced stages of disc degeneration. ⋯ Aggrecanases are involved in aggrecanolysis at both the early and advanced stages of disc degeneration. The aggrecan fragmentation profile analysis demonstrates the involvement of aggrecanases, as well as that of matrix metalloproteinases and/or cathepsins, during disc degeneration.
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Prospective study. ⋯ ROM of the cervical spine decreased by 30.5% after laminoplasty. Kyphosis was developed in 10.6% of the patients. The preoperative factors affecting postoperative kyphosis are diagnosis of myelopathy cases associated with cervical spondylosis, a lordosis angle of <10 degrees, and a kyphotic angle during flexion that is larger than a lordotic angle during extension.
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Prospective observational cohort study. ⋯ The critical degree of spinal cord compression needed to induce clinically significant signs was found between 50 and 60 mm2 of cross-sectional transverse area at the level of maximal compression in association with MRI hyperintensities.