Journal of neurosurgery. Spine
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Perineural cysts have become a common incidental finding during lumbosacral magnetic resonance (MR) imaging. Only some of the symptomatic cysts warrant treatment. The authors describe the successful operative treatment of a patient with, to the best of their knowledge, the largest perineural cyst reported to date. ⋯ The cyst was successfully treated by ligation of the cyst neck together with sectioning of the S-3 nerve root. Postoperative improvement in her symptoms and MR imaging findings were noted. Identification of the nerve root involved by the cyst wall, operative indication, operative procedure, and treatment of multiple cysts are important preoperative considerations.
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The purpose of this study was to evaluate the correlation between adjacent-segment degeneration (ASD) and pelvic parameters in the patients with spondylolytic spondylolisthesis. Sagittal balance is the most important risk and prognostic factor in the development of ASD. The pelvic incidence angle (PIA) is an important anatomical parameter in determining the sagittal curvature of the spine and in the individual variability of the sacral slope and the lordotic curve. ⋯ Conclusions. The development of ASD is closely related to postoperative PIA and PTA, not preoperative PIA and PTA. The measurement of postoperative PIA can be used as a new indirect method to predict the ASD.
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The authors studied the histological and immunohistochemical features of ossified posterior longitudinal ligament (PLL) of the cervical spine, especially in the calcification and ossification front. ⋯ The enchondral ossification process in the ossified PLL was closely associated with degenerative changes of elastic fibers and cartilaginous cartilage formation, together with the appearance of metaplastic hypertrophic cartilage cells and neovascularization. The authors also found that VEGF-positive metaplastic chondrocytes in the ossification front and different expression patterns of collagens probably play some role in the extension of the ossified PLL from the ossification front.
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An understanding of the wear potential of total disc replacements (TDRs) is critical as these new devices are increasingly introduced into clinical practice. The authors analyzed the wear potential of a ProDisc-L implant using an adaptive finite element (FE) technique in a computational simulation representing a physical wear test. ⋯ The chosen design variables had little effect on the resultant wear rates. The comparable wear rate for the THR validation analysis was 16.17 mg per million cycles, indicating that, using this framework, the wear potential of the TDR was equivalent to, if not better, than the THR using joint-specific loading standards.
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Thoracic myelopathy is uncommon compared with cervical myelopathy. In this study, data obtained in patients with thoracic myelopathy caused by degenerative processes of the spine were retrospectively analyzed to clarify the surgical outcomes and to examine the various factors affecting the postoperative improvement. ⋯ Patients with a shorter preoperative duration of symptoms and milder myelopathy experienced significantly better postoperative neurological conditions, which indicated that those who present earlier with fewer disabilities should be recommended to undergo surgery in time, although the surgical treatment for OPLL still involves many problems.