Spine
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A biomechanical study on a pneumatically controlled 7-axis spine simulator using Delron and human cadaveric spine models. ⋯ This extension plate appears to be biomechanically equivalent to the ABC cervical plates with which it was compared in this study.
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Spinal neuropeptide responses in persistent and transient pain following cervical nerve root injury.
Behavioral and immunohistochemical analysis in rat models of persistent and transient allodynia. ⋯ Compression and transection of the cervical nerve root produce different forepaw allodynia responses, with persistent and transient sensitivity, respectively. Spinal neuropeptide expression in these models parallels this sensitivity, suggesting their potential role in pain symptoms.
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An external compression model was used to evaluate gene and protein expression in intervertebral discs with moderate disc degeneration. ⋯ Experimental moderate disc degeneration is characterized by a loss of BMP-2/4 and COL2 positive cells, although gene expression of disc constituents, catabolic enzymes, and growth factors is stimulated to reestablish disc integrity.
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Explant analysis for bone ingrowth of retrieved cervical disc prosthesis in chimpanzees and humans. ⋯ Adequate bony apposition was found in all primate device-to-vertebral body interfaces. Human retrievals also demonstrated significant ingrowth in all four surfaces. This compares with hip and knee arthroplasty percent ingrowth rates of 10% to 30%. All implants had stable fixation judged by radiographs and at the time of implant removal.
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A posterolateral lumbar fusion model in rats. ⋯ Alendronate inhibits spine fusion in rats. Fusion masses in alendronate-treated animals appeared radiographically larger and denser than those in control animals despite lower fusion rates. Quantitative histomorphometry confirmed that alendronate inhibited bone graft resorption and incorporation. We recommend that patients undergoing spine arthrodesis should not take alendronate until fusion is achieved.