Determining the sagittal dimensions of the canal of the cervical spine. The reliability of ratios of anatomical measurements. (1/243)

The ratio of the sagittal diameter of the cervical canal to the corresponding diameter of the vertebral body has been described as a reliable means for assessing stenosis of the canal and detecting those at risk of cervical neuropraxia. The use of ratio techniques has the advantage of avoiding variation in magnification when direct measurements are made from plain radiographs. We examined the reliability of this method using plain lateral radiographs of unknown magnification and CT scans. We also assessed other possible ratios of anatomical measurements as a guide to the diameter of the canal. Our findings showed a poor correlation between the true diameter of the canal and the ratio of its sagittal diameter to that of the vertebral body. No other more reliable ratio was identified. The variability in anatomical morphology means that the use of ratios from anatomical measurements within the cervical spine is not reliable in determining the true diameter of the cervical canal.  (+info)

Relief of obstructive pelvic venous symptoms with endoluminal stenting. (2/243)

PURPOSE: To select patients for percutaneous transluminal stenting of chronic postthrombotic pelvic venous obstructions (CPPVO), we evaluated the clinical symptoms in a cohort of candidates and in a series of successfully treated patients. METHODS: The symptoms of 42 patients (39 women) with CPPVO (38 left iliac; average history, 18 years) were recorded, and the venous anatomy was studied by means of duplex scanning, subtraction venography, and computed tomography or magnetic resonance imaging. Successfully stented patients were controlled by means of duplex scanning and assessment of symptoms. RESULTS: The typical symptoms of CPPVO were reported spontaneously by 24% of patients and uncovered by means of a targeted interview in an additional 47%. Of 42 patients, 15 had venous claudication, four had neurogenic claudication (caused by dilated veins in the spinal canal that arise from the collateral circulation), and 11 had both symptoms. Twelve patients had no specific symptoms. Placement of a stent was found to be technically feasible in 25 patients (60%), was attempted in 14 patients, and was primarily successful in 12 patients. One stent occluded within the first week. All other stents were fully patent after a mean of 15 months (range, 1 to 43 months). Satisfaction was high in the patients who had the typical symptoms, but low in those who lacked them. CONCLUSION: Venous claudication and neurogenic claudication caused by venous collaterals in the spinal canal are typical clinical features of CPPVO. We recommend searching for these symptoms, because recanalization by means of stenting is often feasible and rewarding.  (+info)

Adaptation in the vertebral column: a comparative study of patterns of metameric variation in seven species of small mammals. (3/243)

The pattern of variation of certain vertebral measurements along the vertebral column is known to differ in man and mouse. This paper investigates changes in this pattern in 7 species of small mammals and attempts to correlate them with locomotor adaptations and limb dimensions.  (+info)

Spinal sonography and magnetic resonance imaging in patients with repaired myelomeningocele: comparison of modalities. (4/243)

The goals of this study were to evaluate the feasibility of using ultrasonography of the spine in the follow-up evaluation of patients with repaired myelomeningocele at birth and to compare sonography with the accepted modality of magnetic resonance imaging. Over a period of 4 years we performed 165 sonographic studies in 101 patients; 107 sonographic studies had MR imaging results for comparison. We collected our data prospectively. The quality of the sonograms was good in 110 of 129 studies, acceptable in 17 of 129, and poor in two of 129. The sonographic examinations failed in 33 of 165 studies (20%). Concordant information was obtained between ultrasonography and magnetic resonance imaging in the following percentage of studies: level of the distal end of the cord in 82%, position of the cord in the canal in 59%, presence of hydromyelia in 63%, cord duplication in 96%, adhesions in 16%, intradural mass in 37%, cord measurements in 85%, and dural sac measurements in 83%. At the lumbosacral level, we saw no cord pulsation in 57% of the studies in patients with cord adhesions and in 20% of those without adhesions. At the lower thoracic level, we saw no pulsation in 35% of the studies in patients with cord adhesions and in 7% of those without adhesions. Postoperative studies of cord release surgery in eight patients showed varied findings. We conclude that in those patients who have a spinal defect or interlaminar space allowing proper visualization of the lumbosacral spinal canal, ultrasound can provide fairly similar information to that obtained with magnetic resonance imaging of that area with no need for sedation and at a reduced cost. Ultrasonography seems more sensitive than magnetic resonance imaging in the detection of cord adhesions, which is particularly relevant in the diagnosis of tethering.  (+info)

A foreign body in the spinal canal. A case report. (5/243)

An 18-year-old man who presented with weakness in his lower limbs, had an upper motor neurone lesion at the D12-L1 level. At laminectomy two stone-like objects were found which proved to be bundles of tiny pieces of wood. They are thought to have entered the cord through an abdominal penetrating injury sustained six years previously.  (+info)

Does 'canal clearance' affect neurological outcome after thoracolumbar burst fractures? (6/243)

Surgical decompression of the spinal canal is presently accepted worldwide as the method of treatment for thoracolumbar burst fractures with neurological deficit in the belief that neurological recovery may be produced or enhanced. Our clinical and laboratory experience, however, indicates that the paralysis occurs at the moment of injury and is not related to the position of the fragments of the fracture on subsequent imaging. Since the preoperative geometry of the fracture may be of no relevance, our hypothesis, backed by more than two decades of operative experience, is that alteration of the canal by 'surgical clearance' does not affect the neurological outcome. We have reviewed the existing world literature in an attempt to find evidence-based justification for the variety of surgical procedures used in the management of these fractures. We retrieved 275 publications on the management of burst fractures of which 60 met minimal inclusion criteria and were analysed more closely. Only three papers were prospective studies; the remainder were retrospective descriptive analyses. None of the 60 articles included control groups. The design of nine studies was sufficiently similar to allow pooling of their results, which failed to establish a significant advantage of surgical over non-surgical treatment as regards neurological improvement. Significant complications were reported in 75% of papers, including neurological deterioration. Surgical treatment for burst fracture in the belief that neurological improvement can be achieved is not justified, although surgery may still occasionally be indicated for structural reasons. This information should not be withheld from the patients.  (+info)

Anatomy of deer spine and its comparison to the human spine. (7/243)

The anatomical parameters of the thoracic and lumbar regions of the deer spine were evaluated and compared with the existing data of the human spine. The objective was to create a database for the anatomical parameters of the deer spine, with a view to establish deer spine as a valid model for human spine biomechanical experiments in vitro. To date, the literature has supported the use of both calf and sheep spines as a suitable model for human spine experiments as the difficulty in procuring the human cadaveric spines is well appreciated. With the advent of Bovine Spongiform Encephalopathy (BSE) and its likely transmission to human in form of new variant Creutzfeld Jakob disease (CJD), there is a slight risk of transmission to humans through food chain if proper precautions for disposal of specimen are not adhered to. There is also a significant risk of transmission through direct inoculation to the researchers (Wells et al. Vet. Rec., 1998:142:103-106), working with infected bovine and sheep spine. The deer spines are readily available and there are no reported cases of deer being carriers of prion diseases (Ministry of Agriculture, Fisheries and Food, 1998). Six complete deer spines were measured to determine 22 dimensions from the vertebral bodies, endplates, disc, pedicles, spinal canal, transverse and spinous processes, articular facets. This was compared with the existing data of the human spine in the literature. The deer and human vertebrae show many similarities in the lower thoracic and upper lumbar spine, although they show substantial differences in certain dimensions. The cervical spine was markedly different in comparison. The deer spine may represent a suitable model for human experiments related to gross anatomy of the thoracic and lumbar spine. A thorough database has been provided for deciding the validity of deer spine as a model for the human spine biomechanical in vitro experiments.  (+info)

Migration of a lumboperitoneal shunt catheter into the spinal canal--case report. (8/243)

A 50-year-old female suffered upward migration of a lumboperitoneal (LP) shunt catheter into the spinal canal, manifesting as disturbance of short-term memory. Revision of the shunt confirmed that the tube had migrated into the spinal canal. The tube was pulled back into the peritoneal cavity and attached firmly to the fascia with a new anchoring device. LP shunts have the advantages of technical simplicity and extracranial procedure, but firm fixation is recommended since movements of the spine may cause proximal tube migration.  (+info)