Spine
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Comparative Study
Revision strategies for salvaging or improving failed cylindrical cages.
This is a review of 20 patients who experienced failure of threaded interbody fusion cages and underwent surgical correction. ⋯ All 20 cages failed because of surgical technique rather than an intrinsic defect in fusion cage technology. The factors associated with failure of the original insertion procedure were failure to achieve adequate distraction of the anulus fibrosis; undersized cages, especially when placed through the posterior interbody lumbar fusion approach; cerebrospinal fluid leakage or pseudomeningocele; Type 2 diabetes mellitus; the use of local bone graft rather than iliac crest inside the cage; anterior insertion in an excessively lateral position resulting in symptoms of a far lateral disc herniation; and failure to identify the spinal midline during an anterior approach.
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Comparative Study
In vivo evaluation of coralline hydroxyapatite and direct current electrical stimulation in lumbar spinal fusion.
An animal model of posterolateral intertransverse process lumbar spinal fusion using autologous bone, coralline hydroxyapatite, and/or direct current electrical stimulation. ⋯ Direct-current electrical stimulation increased fusion rates in a dose-dependent manner in a rabbit spinal fusion model. Coralline hydroxyapatite is an osteoconductive bone graft substitute, and thus requires an osteoinductive stimulus to ensure reliable fusion rates. Furthermore, coralline hydroxyapatite and direct current electrical stimulation can be used together to increase fusion rates in a rabbit spinal fusion model while avoiding the morbidity associated with harvesting iliac crest bone.
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Comparative Study
An immunohistochemical study of nerve structures in the anulus fibrosus of human normal lumbar intervertebral discs.
The innervation of the anulus fibrosus of human macroscopically normal intervertebral discs from five patients was investigated immunohistochemically. ⋯ In anulus fibrosus samples from macroscopically normal discs, a general marker for nerve endings can be found at a depth of a few millimeters, whereas neuropeptide markers show nerves only in the outermost layers of the anulus fibrosus. This absence of demonstrable nerves in deeper anulus fibrosus in normal discs is probably not a methodologic artifact, because blood vessels have also been demonstrated only at the disc surface. It is, however, possible that neuropeptide nerves also penetrate to a depth of a few millimeters, but that methodologic limitations permit the visualization of only the neuropeptide nerves closest to the disc surface. The results of the present study lend support to previous suggestions that, except at the surface, a normal intervertebral disc is almost without innervation.
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Case Reports
Extraosseous extension of vertebral hemangioma, a rare cause of spinal cord compression.
Case report. ⋯ Extraosseous extension of vertebral hemangiomas is a rare cause of thoracic spinal cord compression. As such, the available data are derived from reports based on series involving only a small number of cases, rather than on results of randomized controlled trials. Those causing progressive neurologic symptoms should be surgically decompressed, with the specific procedure determined by the extent and site of the lesion. Preoperative angiography is recommended, but embolization is not always necessary or even possible. Postoperative radiotherapy is recommended when tumor removal is subtotal.
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Comparative Study
Progesterone is neuroprotective after acute experimental spinal cord trauma in rats.
A standardized rat contusion model was used to test the hypothesis that progesterone significantly improves neurologic recovery after a spinal cord injury that results in incomplete paraplegia. ⋯ Rats treated with progesterone had a better clinical and histologic outcome compared with the various control groups. These results indicate potential therapeutic properties of progesterone in the management of acute spinal cord injury.