Journal of spinal disorders & techniques
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J Spinal Disord Tech · Oct 2004
Pseudocystic degeneration of the lumbar ligamentum flavum: a little known entity.
The objective of this work was to investigate the clinical and histologic features of patients with pseudocystic lesions of the ligamentum flavum in the lumbar region of the spinal canal and ascertain the existence of genuine ligamentum flavum pseudocysts. ⋯ Radiologic, surgical, and histologic findings suggest that the pseudocystic degeneration of the ligamentum flavum represents a genuine entity that is associated with degenerative changes of the structures of the respective lumbar spine segment. These pseudocystic lesions may compress the adjacent nerve roots, provoking symptoms and signs of radiculopathy. The findings suggest that the surgical treatment not only must consist of removal of the pseudocyst but must also include a radical extirpation of the ligamentum flavum surrounding the pseudocyst to avoid recurrence of such a lesion.
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J Spinal Disord Tech · Oct 2004
Comparative StudySegmental lumbar lordosis: manual versus computer-assisted measurement using seven different techniques.
Obliteration of end-plate landmarks by interbody fusion has made the traditional measurement of segmental lumbar lordosis nearly impossible. Because the L4-L5 and L5-S1 levels are most likely to be subjected to fusion procedures or arthroplasty and contribute to more than half of normal lumbar lordosis, it is crucial to identify a reproducible and accurate means of measuring segmental lordosis at these levels. ⋯ Variance calculations identified the Cobb technique and the posterior vertebral body technique as the least variable measurement techniques for the L4-L5 and L5-S1 levels, respectively; however, there was no statistical significance. In direct comparison, the manual and computer-assisted techniques were found to be statistically equivalent with similar degrees of variance. We believe that the anterior vertebral technique, which did not demonstrate a significant difference from other techniques, will prove to be the most reliable method of assessing segmental lumbar lordosis in patients before surgery, after interbody fusion, and after motion-sparing disc arthroplasty.
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J Spinal Disord Tech · Oct 2004
Cervical myelopathy due to OPLL: clinical evaluation by MRI and intraoperative spinal sonography.
Concerning the relationship between morphology and clinical outcome, there have been many reports using computed tomography/myelography but not so many using axial magnetic resonance imaging (MRI) of the spinal cord. This is the first report to correlate axial cord image, intensity changes in MRI, and cord expansion pattern using intraoperative ultrasonography. ⋯ Patients with triangular deformity of the cord have atrophy as confirmed on MR studies where there is a low T1 and high T2 signal in the cord. Poor postoperative clinical recovery correlates with the lack of postoperative cord expansion on either MR or ultrasound evaluations. Those with either teardrop or boomerang deformities demonstrate a relatively good recovery rate.
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Facet joint cysts are commonest at the L4-L5 level and are associated with facet joint degeneration and type III (degenerative) spondylolisthesis. It is extremely rare for facet joint cysts to cause symptomatic cauda equina compression. Three elderly patients presented to us with significant cauda equina compression caused by facet joint cysts. ⋯ Lumbar spine surgery (decompression and cyst resection) was successful in resolving symptoms in all three, even though two patients had significant neurologic compromise before surgery. The occurrence of facet joint cysts in older patients can be associated with other degenerative neurologic conditions, and the diagnosis might not be apparent early. We suggest that in older patients who have a mixed picture of central and peripheral neurologic compromise, this diagnosis should be considered and investigation of the whole of the spine, not just the brain and spinal cord, should be undertaken.
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J Spinal Disord Tech · Oct 2004
Poroelastic analysis of lumbar spinal stability in combined compression and anterior shear.
A three-dimensional poroelastic finite element (FE) L2-L3 model was developed to study lumbar spinal instability and intrinsic parameters in the intervertebral disc (IVD). ⋯ The predicted results using poroelastic elements provide new insight into the IVD in providing the spinal stiffness under combined loading.