European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society
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As the immature spinal cord was nerve growth permissive, we examined glial reactions that influence regeneration of the spinal cord in a fetal rat spinal cord injury model. ⋯ In the present study, collagen fibers and scar formation were seen in the severed spinal cords of adult rats, but scar formation was not seen in the fetal rat cordotomy group. Lack of inflammation and scar formation thus appear advantageous for regeneration of the fetal spinal cord. Between fetal and mature rats, chronological changes in the immunohistochemical reactions of astrocytes and microglia following cordotomy were compared, and the results confirmed many differences. The results of the present study suggest that the presence of activated glial cells around damaged central nervous tissue and the quick disappearance of these cells after injury are important for the repair of damaged central nervous system tissue, and that the role of glial cells in nerve regeneration can change depending on the level of maturity of glial cells or surrounding cells, site of injury, or the state of tissue around the injury.
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Two cases with a long-standing thoracolumbar kyphosis due to ankylosing spondylitis are presented with a symptomatic localized destructive kyphotic lesion of the spine. Clinical and radiographic findings demonstrated a progressive vertebral and discovertebral kyphotic pseudarthrosis, known as an Andersson lesion, at the L1 and L1-2 level, respectively. ⋯ The indication for surgery, the surgical technique and the 2 years' clinical results are described. In addition, the difficulties experienced with preoperative deformity planning are evaluated.
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Polyetheretherketone (PEEK) is a novel polymer with potential advantages for its use in demanding orthopaedic applications (e.g. intervertebral cages). However, the influence of a physiological environment on the mechanical stability of PEEK has not been reported. Furthermore, the suitability of the polymer for use in highly stressed spinal implants such as intervertebral cages has not been investigated. ⋯ The stress and strain maxima in the implants were well below the material strength limits of PEEK. In summary, the experimental results verified the mechanical stability of the PEEK-OPTIMA polymer in a simulated physiological environment, and over extended loading periods. Finite element analysis supported the use of PEEK-OPTIMA for load-bearing intervertebral implants.
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A retrospective clinical-radiological study to evaluate the long-term outcome after artificial disc replacement was performed. The objective is to investigate long-term results after implantation of a modular type artificial disc prosthesis in patients with degenerative disc disease (DDD). Total disc replacement (TDR) is a surgical procedure intended to save segmental spinal function, and thus replace spondylodesis. ⋯ Although no adjacent segment degeneration was observed in the functional implants (17%), these patients were significantly less satisfied than those with spontaneous ankylosis. TDR, nowadays, is an approved procedure. Proof that long-term results of TDR implantation in DDD are at least as good as fusion results is still missing.
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The goal of the present study was to quantitatively assess the proliferation index and progesterone receptor status of spinal versus intracranial meningiomas and to determine if these biological indicators can describe the clinical behavior of these tumors. This information could provide the spinal surgeon with important additional information concerning surgical management and follow-up recommendations for the individual patient. ⋯ Spinal and intracranial meningiomas differ in their proliferation activity but not in their PR status. However, despite lower proliferation rates, time to recurrence in spinal and cranial meningiomas is comparable in totally excised tumors. Further studies are needed to determine the role of other biological indicators in spinal meningioma growth and response to therapy.