A method is described whereby fractures of the neural arch similar to those in spondylolysis are produced experimentally. The forces, bending moments and displacements required to initiate the fractures are given; The mechanical aspects in the aetiology of spondylolysis are explained by a simplified two-dimensional force analysis. (+info)
Spondyloptosis and multiple-level spondylolysis.
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An unusual case of a combination of multiple bilateral spondylolyses (L2, 3 and 4), spondylolisthesis at L3/4, spondyloptosis at L4/5 and sacralization of L5 in a teenage female is described. The patient had severely increasing lower back pain radiating to the left lower limb. Radiography identified the abnormalities and myelography revealed complete obstruction and compression of the thecal sac at the L4/5 level. The case was treated surgically by posterior decompression, corpectomy and fusion in a three-stage operation. The follow-up was extended to 2 years with no complications. No similar case has previously been reported. (+info)
The assessment of appropriate indications for laminectomy.
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We have developed criteria to determine the appropriate indications for lumbar laminectomy, using the standard procedure developed at the RAND corporation and the University of California at Los Angeles (RAND-UCLA). A panel of five surgeons and four physicians individually assessed 1000 hypothetical cases of sciatica, back pain only, symptoms of spinal stenosis, spondylolisthesis, miscellaneous indications or the need for repeat laminectomy. For the first round each member of the panel used a scale ranging from 1 (extremely inappropriate) to 9 (extremely appropriate). After discussion and condensation of the results into three categories laminectomy was considered appropriate in 11% of the 1000 theoretical scenarios, equivocal in 26% and inappropriate in 63%. There was some variation between the six categories of malalignment, but full agreement in 64% of the hypothetical cases. We applied these criteria retrospectively to the records of 196 patients who had had surgical treatment for herniated discs in one Swiss University hospital. We found that 48% of the operations were for appropriate indications, 29% for equivocal reasons and that 23% were inappropriate. The RAND-UCLA method is a feasible, useful and coherent approach to the study of the indications for laminectomy and related procedures, providing a number of important insights. Our conclusions now require validation by carefully designed prospective clinical trials, such as those which are used for new medical techniques. (+info)
MR imaging for early complications of transpedicular screw fixation.
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This series comprises ten patients treated with transpedicular screw fixation, who suffered early postoperative problems such as radicular pain or motor weakness. Besides plain radiographs, all patients were also evaluated with MR imaging. Three patients were reoperated for either repositioning or removal of the screws. MR images, especially T1-weighted ones, were very helpful for visualizing the problem and verifying the positions of the screws. In cases of wide areas of signal void around the screws, the neighboring axial MR images at either side, which have fewer artifacts, gave more information about the screws and the vertebrae. (+info)
Degenerative spondylolisthesis. Developmental or acquired?
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Degenerative spondylolisthesis is four times more common in women than in men. Although this gender difference has long been recognised there has been no explanation for it. We have examined the radiographs and CT scans of 118 patients over the age of 55 years and of a control group under the age of 46 years. Our findings confirmed the presence of more sagittally-orientated facet joints in patients with degenerative spondylolisthesis but did not show that the gender difference can be explained by the morphology of the facet joint. Furthermore, we conclude that the increased angle of the facet joint is the result of arthritic remodelling and not the primary cause of degenerative spondylolisthesis. It is more likely to be due to loss of soft-tissue resilience with subsequent failure of the facet joints which are acting as the last restraints to subluxation. (+info)
Ehlers-Danlos syndrome associated with multiple spinal meningeal cysts--case report.
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A 40-year-old female with Ehlers-Danlos syndrome was admitted because of a large pelvic mass. Radiological examination revealed multiple spinal meningeal cysts. The first operation through a laminectomy revealed that the cysts originated from dilated dural sleeves containing nerve roots. Packing of dilated sleeves was inadequate. Finally the cysts were oversewed through a laparotomy. The cysts were reduced, but the postoperative course was complicated by poor wound healing and diffuse muscle atrophy. Ehlers-Danlos syndrome associated with spinal cysts may be best treated by endoscopic surgery. (+info)
Traumatic L5-S1 spondylolisthesis: report of three cases and a review of the literature.
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The literature reports that traumatic spondylolisthesis of L5 is an uncommon lesion. The authors report their experience of three cases of this particular fracture-dislocation of the lumbosacral spine. They stress the importance of certain radiographic signs in the diagnosis: namely, the presence of unilateral multiple fracture of the transverse lumbar apophysis. As far as the treatment is concerned, they state the need for an open reduction and an internal segmental fixation by posterior approach. A preoperative MRI study appears mandatory in order to evaluate the integrity of the L5-S1 disc. In the event of a traumatic disruption of the disc, they state the importance of posterior interbody fusion by means of a strut graft carved from the ilium or, in case of iliac wing fracture (which is not uncommon in these patients), by means of interbody cages. (+info)
Traumatic spondylolisthesis of the axis: treatment rationale based on the stability of the different fracture types.
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Thirty-nine consecutive patients, 22 male and 17 female with an average age of 37.6 years, with traumatic spondylolisthesis of the axis were reviewed. The cause of injury in 75% of the patients was a road traffic accident. The fractures were classified according to Effendi et al., the type II fractures were further divided into three subgroups: flexion, extension and listhesis injuries. There were 10 type I (25.7%) and 29 type II fractures (74.4%); of these, 12 (30.8%) were classified as flexion-type, 2 (5.1%) as extension-type and 15 (38.5%) as listhesis-type. We did not identify any case of type III injury. Overall, 43.5% of the patients had sustained a significant head or chest trauma, with the highest incidence for type II listhesis injuries. Significant neurological deficits occurred in four patients (10.3%); in all four,the fracture was classified as a type II listhesis. All ten type I injuries were successfully treated with a cervical orthosis. Ten of the 12 type II flexion injuries demonstrated significant angulation. Two were treated with internal stabilisation, in seven with a halo device and one with a minerva plaster of Paris (PoP). Healing was uneventful in all ten patients. For the remaining two stable type II flexion injuries, application of a hard collar was adequate, as was the case for the two stable type II extension injuries. Six of the 15 type II spondylolisthesis injuries underwent primary internal stabilisation, and healing was uneventful in all cases. In four (44.4%) of the nine injuries that were primarily treated with a halo device/minerva PoP, secondary operative stabilisation had to be performed. The classification of Effendi et al. provides a complete description of the different fractures. However, further distinction of the type II injuries regarding their stability is mandatory. Type II spondylolisthesis injuries are unstable, with a high number of associated injuries, a great potential for neurological compromise and significant complications associated with non-operative treatment. The majority of type II extension and type II flexion injuries can be successfully treated with nonrigid external immobilisation. (+info)