Traumatic lateral lumbosacral dislocation: one case and review of literature

OBJECTIVE: Lateral traumatic lumbosacral dislocation is a rare and severe lesion of the lumbosacral junction. Only one case has been reported in the literature. We report a new case of pure lateral lumbosacral dislocation. METHODS: A 27-year-old man had an isolated pure lateral traumatic dislocation of the lumbosacral junction after a motorcycle accident. The diagnosis and the therapeutic course are analyzed and discussed. RESULTS: Traumatic lumbosacral dislocation usually occurs in patient with multiple traumas. Generally, in the case of complete fracture-dislocation, on lateral radiographs one can observe the L5 vertebra slippage over the sacrum, resulting from an associated severe disc disruption. This feature was not seen in our patient. Surgical treatment consisted of an open reduction of the dislocation, stabilization with posterior instrumentation, and a lumbosacral arthrodesis by posterolateral grafting. In cases of pure lateral dislocation, short instrumentation can be recommended, extending from L5 to S1. Addition of an interbody fusion should be considered when the L5-S1 disc is disrupted, which is responsible for the anterior slippage of L5 over S1. Disc disruption can be evoked on preoperative magnetic resonance imaging (MRI) and intraoperatively by exploring the spinal canal. CONCLUSIONS: Pure lumbosacral dislocation with a lateral translation seemed to have no disc disruption as observed in complete fracture dislocation. Nevertheless, we recommend looking for an L5-S1 disc disruption either on preoperative MRI or during surgical exploration.     

Traumatic dislocation of the lumbosacral junction diagnosis, anatomical classification and surgical strategy

PURPOSE OF THE STUDY: Traumatic lumbosacral dislocation is a rare lesion often characterised by a fracture dislocation of L5-S1 articular facets associated with anterior L5 slipping. Because of its rarity, the surgical strategy of lumbosacral traumatic dislocation remains controversial. We report the most important series of traumatic lumbosacral dislocation. The cases of six men and five women are presented. We discuss the diagnosis and surgical treatment options regarding the different type of lesions. A moderate anterior slipping of L5 over S1 was present in eight cases. The lesion was a bilateral lumbosacral fracture dislocation in eight cases, a pure lateral dislocation in two cases and a unilateral rotatory dislocation in one case. Patients were multiple-trauma patients in eight cases. A radicular deficit was present in two cases. All patients were treated surgically with a posterior osteosynthesis and fusion. A circumferential fusion was made in six cases. In four cases, the anterior fusion was made during the posterior approach. The postoperative course was favorable in all the cases. One patient necessitated secondarily an iterative posterior lumbosacral fixation and anterior fibular bone graft because of a lumbosacral pseudarthrosis. Traumatic dislocation of the lumbosacral junction is a rare and severe spinal fracture which occurs in patients after high energy trauma and could be initially misdiagnosed. We devised a new classification based on anatomical lesions. Treatment is always surgical, requiring reduction, osteosynthesis, and fusion. In case of L5 anterior slipping, it is crucial to assess the L5S1 disc by MRI or surgical exploration for disc disruption. In such case, we recommend to perform circumferential fusion to prevent lumbosacral pseudarthrodesis.     

Transvertebral Transsacral strut grafting for high-grade isthmic spondylolisthesis L5-S1 with fibular allograft

STUDY DESIGN: A clinical retrospective study was conducted. OBJECTIVE: To evaluate the clinical and radiographic outcomes of 25 consecutive patients with symptomatic high-grade isthmic spondylolisthesis at L5-S1 treated by decompression and transvertebral, transsacral strut grafting with fibular allograft. SUMMARY OF BACKGROUND DATA: Symptomatic high-grade isthmic spondylolisthesis serves as a challenging clinical problem. Traditional treatment by in situ posterolateral arthrodesis has been associated with pseudarthrosis rates up to 50%. Even with successful posterolateral fusion, the graft is in an unfavorable biomechanical environment, owing to it being under tension, which can allow for progression of lumbosacral kyphosis (slip angle) and sagittal translation (slip). Open reduction of spondylolisthesis improves the biomechanical situation by allowing a trapezoidal interbody graft at L5-S1, but is associated with neurologic deficits in up to 30% of patients. The technique used in this particular study achieves the biomechanical goal of a structural interbody construct without the necessity of anatomically reducing the translational slip. The fibular strut grafts were placed through an anterior approach as part of an anterior/posterior procedure, or via a posterior approach as part of a posterior-only procedure. METHODS: A consecutive series of 25 symptomatic patients with high-grade isthmic spondylolisthesis at L5-S1 had an average age of 29.8 years. Six patients were 16 years or younger. Eight patients underwent a posterior-only approach with posterior transosseous fibular strut grafting across S1 into the L5 vertebral body combined with posterolateral arthrodesis L4-S1 using a pedicle screw-rod construct. Seventeen patients underwent a combined anterior/posterior approach with transosseous fibular allograft strut grafting at L5-S1 and L4-L5 interbody arthrodesis using a femoral ring allograft supplemented with L4-S1 posterior pedicle screw-rod instrumentation. No reduction attempts were performed, other than those occurring spontaneously by patient positioning and decompression. Patients were evaluated for clinical improvement and radiographically. Clinical outcomes were measured with the scoliosis research society outcome instrument. Radiographs were followed for arthrodesis, translation, and slip angle. Mean follow-up was 39 months (range, 30 to 71 mo). All patients preoperatively had a grade III to V slip using the Meyerding classification (mean 3.7). The slip angle averaged 37 degrees. RESULTS: The postoperative mean slip grade was 3.5 compared with 3.7 preoperatively (no significant difference). The mean slip angle improved to 27 degrees (8 to 40 degrees) postoperatively from 37 degrees (13 to 51 degrees) preoperatively (P<0.05). All patients went on to a stable arthrodesis, with no progression in slip or slip angle. There were no permanent neurologic deficits among any of the subjects, and all patients demonstrated improvement in their preoperative gait disturbance. Scoliosis research society functional outcome score showed 24/25 extremely satisfied or somewhat satisfied at latest follow-up. CONCLUSIONS: Treatment by this method showed improvement in lumbosacral kyphosis while avoiding the neurologic injury risk associated with open slip-reduction maneuvers. Despite no reduction in translational deformity, this technique offers excellent fusion results, good clinical outcomes, and prevents further sagittal translation and lumbosacral kyphosis progression.     

Traumatic spondyloptosis resulting from high-energy trauma concurrent with a tonic-clonic seizure

Background contextTraumatic lumbosacral dislocation injuries are rare, high-energy injuries that are challenging to surgically manage.PurposeTo report a patient with a traumatic spondyloptosis of L5 on S1 as a result of bilateral pedicle fractures of L4 and L5 occurring during a motor vehicle accident, concurrent with a tonic-clonic seizure. The mechanism and treatment of the injury are discussed.Study designClinical case report and literature review.MethodsA staged circumferential fusion was performed with posterior reduction of L5 to the sacrum and instrumentation and fusion from L2 to the pelvis, followed 12 days later by anterior diskectomies and arthrodesis from L3 to S1.ResultsNear anatomic reduction and solid fusion were obtained and maintained at 3-year follow-up. The patient remained neurologically intact in all lumbosacral roots throughout the course of treatment.ConclusionsThe injury pattern described is quite rare. This case of multilevel, bilateral pedicle fracture with traumatic L5–S1 spondyloptosis was successfully treated by circumferential reduction and arthrodesis without neurological injury.     

Acute traumatic L5-S1 spondylolisthesis

Acute traumatic L5-S1 spondylolisthesis is a rare condition, almost exclusively the result of major trauma, frequently associated with L5 transverse process fracture and neurologic deficit. In recent years, open reduction and internal fixation with posterior stabilization has been the method of treatment most frequently reported. In the current case, the lesion was found in a victim of an automobile accident. Signs of a right L5 root deficit but no sphincter dysfunction were present. A computed tomography scan revealed several fractures in the posterior parts of L5 and anterior displacement of L5 on S1. A magnetic resonance imaging (MRI) scan verified that the lesion was indeed acute by showing the ruptured L5 disc and posterior ligaments, thereby demonstrating the importance of MRI in the planning of the treatment of these lesions. This case was successfully treated with an acute circumferential instrumented L4-S1 spondylodesis.     

Surgery for severe spondylolisthesis and spondyloptosis

Objective  Restoration of a normal profile of spinal column by complete or almost complete reduction, stabilization achieved by instrumentation and fusion of the lumbosacral intervertebral segment. Alleviation or at least marked reduction of pain and neurologic deficits present before surgery. Indications  High grade, that means usually spondylolisthesis grade IV according to Meyerding or spondyloptosis. Patients with progression of slip. Contraindications  Osteopenia. Spondylolistheses which do not necessitate an opening of the spinal canal. Possibility of adequate anterior access to the lumbosacral disk. Surgical Technique  Posterior decompression and resection of the sacral dome, reduction of L5 over the sacrum and posterior interbody fusion L5/S1 with two autogenous bi- or tricortical bone grafts harvested from the iliac crest. Results  Between January 1995 and January 1998, we used the described technique in eleven patients. Six patients had a grade IV spondylolisthesis and five a spondyloptosis. Previous surgery had been done in four patients. A complete or almost complete reduction was possible in ten patients. No pseudarthrosis nor loss of correction were seen. Neurologic deficits improved in five of six patients. All patients noted an improvement of symptoms. Postoperative complications in previously operated patients: one dura lesion, one deficit of the S1 nerve root diagnosed postoperatively, and one inadequate reduction. Postoperative complications in the remaining seven, not previously operated patients: one instability of the adjacent segment and a transient irritation of the L5 nerve root in two patients.     

Traumatic noncontiguous double fracture-dislocation of the lumbosacral spine.

BACKGROUND CONTEXT: To our knowledge, the presence of noncontiguous fracture-dislocation of the lumbosacral spine occurring at two levels has not been reported. The etiology, evaluation, and treatment of the unusual injury is presented. PURPOSE: To notify spinal traumatologists about the possibility of this unusual injury. STUDY DESIGN: A case report of an unusual noncontiguous double fracture-dislocation of the lumbosacral spine. METHODS: A 26-year-old man was involved in a motor vehicle accident where his car fell over a bridge and plummeted approximately 300 feet before hitting the ground. The patient was transported to a major medical center where he was found to be conscious, and amazingly, his only major injury was fracture-dislocations of L2-L3 and L5-S1. His preoperative neurologic status showed a partial paraparesis to all motor groups of the lower extremities bilaterally. RESULTS: The patient underwent a posterior reduction, instrumentation, and fusion from L1 to S1 with autogenous bone graft and segmental pedicle screw instrumentation. One week postoperatively, he underwent an anterior spinal fusion of L5/S1. Postoperatively, his neurologic status improved allowing him to be ambulatory, with a normal lumbosacral alignment being well-maintained. CONCLUSIONS: Noncontiguous double fracture-dislocation of the lumbosacral spine is an unusual injury, which results from a very high-energy trauma. Prompt recognition of the injuries, reduction of the fracture-dislocations, and posterior stabilization is recommended for neural decompression, spinal alignment, and long-term stabilization.     

Traumatic lumbosacral fracture dislocation: a case report and review of the literature

Lumbosacral dislocation is uncommon. We report a case of traumatic lumbosacral dislocation which occurred in a 33-year-old pedestrian traffic accident victim. The posterior impact produced lumbar injury with diffuse pain exacerbated at the lumbosacral junction. Ecchymotic diffusion involving the entire lumbar region fluctuated due to the presence of a subcutaneous hematoma. The neurological examination revealed incomplete L5 paraplegia. Standard x-rays revealed L5-S1 spondylolisthesis and fracture of the L5 spinous process as well as fractures of the L3, L4, and L5 transverse processes. Computed tomography disclosed biarticular L5-S1 fracture dislocation and a voluminous herniation of the L5-S1 disc. Emergency surgery was performed and revealed subaponeurotic detachment from T4 to S1 and bald iliac pyramids. After L5 laminectomy and extraction of the voluminous herniation of the L5-S1 disc, a short L5-S1 posteriolateral fusion was achieved using pedicular screws and two rods on either side as well as a posterolateral iliac autograft. The clinical course was satisfactory with nearly complete neurological recovery (persistent levator ani paresis). This clinical case and a review of the literature illustrate the pathogenic, clinical, radiological and therapeutic aspects of lumbosacral fracture dislocation.     

Cauda equina syndrome after in situ arthrodesis for severe spondylolisthesis at the lumbosacral junction

Relative stretching of the cauda equina over the posterosuperior border of the sacrum can be found in all patients who have Grade-III or IV spondylolisthesis at the lumbosacral junction. We identified twelve patients, all less than eighteen years old, who had cauda equina syndrome after in situ arthrodesis for Grade-III or IV lumbosacral spondylolisthesis. In all twelve patients, posterolateral arthrodesis had been done bilaterally through a midline or paraspinal muscle-splitting approach. Nothing in the operative reports suggested that the cauda equina had been directly injured during any of the procedures. Five of the twelve patients eventually recovered completely. The remaining seven patients had a permanent residual neurological deficit, manifested by complete or partial inability to control the bowel and bladder. If dysfunction of the root of the sacral nerve is noted preoperatively in a patient who has lumbosacral spondylolisthesis, decompression of the cauda equina concomitant with the arthrodesis should be considered. An acute cauda equina syndrome that follows a seemingly uneventful in situ arthrodesis for spondylolisthesis is best treated by an immediate decompression that includes resection of the posterosuperior rim of the dome of the sacrum and the adjacent intervertebral disc. In addition, posterior insertion of instrumentation and reduction of the lumbosacral spondylolisthesis should be considered.     

Treatment of congenital spondyloptosis in an 18-month-old patient with a 10-year follow-up.

STUDY DESIGN: Case report. OBJECTIVES: To present the case of a patient with congenital spondyloptosis treated and followed over 10 years. SUMMARY OF BACKGROUND DATA: The surgical management of spondyloptosis in children is variably reported in the literature. Some authors propose that posterior fusion in situ is a safe and reliable procedure, whereas others suggest that reduction of the slipped vertebra may prevent some of the adverse sequelae of in situ fusion, which include nonunion, bending of the fusion mass, and persistent lumbosacral deformity. Many investigators advocate a combined anterior and posterior fusion using instrumentation. METHODS: At the time of the first symptoms an 18-month-old boy with congenital spondyloptosis of L5-S1 was referred to the authors' institution. Because of the progression of pain, neurologic disturbance, mild foot deformity, muscle contractures, and lumbosacral kyphosis, surgical intervention was undertaken. Operative intervention began with a resection of the L5 lamina and wide bilateral L5 nerve root decompression. This was followed by anterior subtotal resection of L5 and interbody bone graft of the morcelized vertebral body for fusion from L5 to S1. The next step was reduction of the spondyloptosis and stabilization by posterior instrumentation L2-S1 with a sacral Cotrel-agraffe device. RESULTS: The procedure achieved almost complete reduction of the spondyloptosis with near-normal restoration of lumbar lordosis allowing more physiologic lumbar spinal biomechanics. There were no neurologic complications. After surgery there was no suggestion of back pain or gait disturbance and no progression of any deformity. CONCLUSION: In the treatment of severe congenital spondylolisthesis a staged procedure of decompression, reduction, and instrumented fusion is recommended for those cases in which intervention is indicated.     

Posterior extrusion of Biocompatible Orthopaedic Polymer (BOP) graft mimicking a calcified lumbar disc herniation: case report

OBJECTIVE AND IMPORTANCE: We present a case of intracanalar extrusion of a L5S1 Biocompatible Orthopaedic Polymer (BOP) graft associated with a L4L5 disc herniation 19 years after a lumbar intersomatic fusion for a L5S1 disc herniation. Radiological aspect of this complication should be recognized by neurosurgeons. CLINICAL PRESENTATION: A 55-year old man presented with a right L5 sciatic pain. Neurological examination found a severe weakness in dorsal flexion of the foot. A lumbar CT scanner disclosed aspects consistent with right L4L5 and huge calcified L5S1 lumbar disc herniation. INTERVENTION: The patient was operated via a bilateral paravertebral approach and a L5 laminectomy. A dense and extensive epidural scarring was seen. The right L4L5 herniated disc was excised. At the left L5S1 level, fibres from a BOP graft had separated into large fragments extruded into the vertebral canal through the dura. The fibres could only be removed partially because of nerve roots adherence. The patient developed postoperative cerebrospinal fluid (CSF) leakage that required a second operation for dural closure. The postoperative course was uneventful and the patient recovered the right L5 root deficit. CONCLUSION: Neurosurgeons should be aware of the radiological aspect of this complication. If it is recognized on CT scan and asymptomatic, conservative management should be proposed because of the risk of nerve roots injury or postoperative CSF leakage.     

Traumatic L4-5 Spondylolisthesis: case report and literature review

We report a case of traumatic L4/L5 spondylolisthesis caused by fall of heavy weight on the back of a construction worker. CT scan showed dislocation of left L4/5 facet with fracture of right L5 facet. MRI showed ruptured intervertebral disc suggestive of acute lesion. The patient was treated surgically 7 days after the injury and posterior L3/4/5 instrumentation with posterolateral and posterior lumbar interbody fusion using mesh cage. At 18-month follow-up, reduction was maintained and solid fusion of interbody and posterolateral grafts was achieved.     

Herniated intervertebral disc associated with a lumbar spine dislocation as a cause of Cauda Equina syndrome: a case report

To report a case of Cauda Equina syndrome with the completion of the paralysis after the reduction of a L4L5 dislocation due to a herniated disc. Although several articles have described a post-traumatic disc herniation in the cervical spinal canal, this is not well known in the lumbar region. A 30-year-old man was admitted to the emergency room with blunt trauma to the chest and abdomen with multiple contusions plus a dislocation of L4-L5 with an incomplete neurological injury. After an emergency open reduction and instrumentation of the dislocation, the patient developed a complete cauda equina syndrome that has resulted from an additional compression of the dural sac by a herniated disc. In a dislocation of the lumbar spine, MRI study is mandatory to check the state of the spinal canal prior to surgical reduction. A posterior approach is sufficient for reduction of the vertebral displacement, however an intra-canal exploration for bony or disc material should be systematically done.     

Treatment of symptomatic spondyloptosis in an adult previously treated with in situ fusion and instrumentation by L5 vertebrectomy and L4-S1 instrumented reduction.

BACKGROUND CONTEXT: One traditional treatment for spondylolisthesis is fusion. However, for high-grade spondylolisthesis and spondyloptosis, posterior fusion has had high rates of nonunion, progression, and persistent physical deformity. Thus, some surgeons have recommended reduction and instrumentation. One such technique (Gaines procedure) entails a two-stage procedure: L5 vertebrectomy anteriorly, followed by resection of the L5 posterior elements and instrumented reduction of L4 onto S1. However, to our knowledge, there is no report of reversing the fusion and deformity reduction in a symptomatic patient with previous solid fusion of the spondyloptosis at L5-S1. PURPOSE: To present the first reported revision via the Gaines procedure for failed fusion secondary to spondyloptosis. STUDY DESIGN: Patient report. METHODS: A 24-year-old woman, who had undergone multiple procedures for L5-S1 spondylolisthesis and a final fusion and instrumentation attempt, presented with continued urinary retention, leg and back pain, and inability to stand. She subsequently underwent posterior hardware removal, followed by anterior L5 vertebral body resection. In the second stage, she had posterior osteotomy of the previous L5-S1 fusion, resection of the posterior elements of L5, and reduction and instrumentation of L4 to S1. RESULTS: At the 2-year follow-up, she had full resolution of symptoms, full return of motor strength, and resolution of urinary retention. CONCLUSIONS: The Gaines procedure has been performed successfully in patients without previous fusions at the level of spondylolisthesis or spondyloptosis. Patients for whom the traditional posterior fusion fails still may be candidates for this procedure, albeit at increased risk of neurologic injury.     

The effect of injury on rotational coupling at the lumbosacral joint. A biomechanical investigation.

The lumbosacral joint is frequently indicated as a source of low-back pain, a cause of which may be abnormal patterns of vertebral motions. The goal of this study was to describe the influence of injury on the coupled motions of the L5-S1 joint in a human cadaveric model. Nine whole lumbosacral spine specimens were studied under the application of flexion, extension, left/right axial torque and right/left lateral bending pure moments. Injuries to the posterior ligaments, intervertebral disc, and articular facets at L5-S1 were produced, and the motion at L5-S1 was determined after each sequential injury. No significant coupled rotations were observed under flexion or extension moments. Under axial torque, lateral rotation at L5-S1 occurred to the same side as the applied torque and increased significantly only after injury to the intervertebral disc. Also coupled to axial torque was flexion rotation in the intact specimen, which became extension rotation after facetectomy. Under lateral bending moments, coupled axial rotation was to the opposite side of the applied moment and increased significantly only after removal of the facets of L5. Based on these results, it was concluded that intervertebral disc most resisted the coupled motion of lateral rotation under the application of axial torque, whereas the articular facets most resisted the coupled axial rotation under the application of lateral bending at the lumbosacral joint. Also, the facets were the structures that produced the flexion rotation of L5 on S1 under axial torque loading.     

Total L-5 spondylectomy and reconstruction of the lumbosacral junction. Technical note

The authors describe a technique for total L-5 spondylectomy and reconstruction of the lumbosacral junction. The technique, which involves separately staged posterior and anterior procedures, is reported in two patients harboring neoplasms that involved the L-5 level. The first stage consisted of a posterior approach with removal of all posterior bone elements of L-5 and radical L4-5 and L5-S 1 discectomies. Lumbosacral and lumbopelvic instrumentation included pedicle screws as well as iliac screws or a transiliac rod. The second stage consisted of an anterior approach with mobilization of vascular structures, completion of L4-5 and L5-S1 discectomies, and removal of the L-5 vertebral body. Anterior lumbosacral reconstruction included placement of a distractable cage and tension band between L-4 and S-1. Allograft bone was used for fusion in both stages. No significant complications were encountered. At more than 1 year of follow-up, both patients were independently ambulatory, without evidence of recurrent or metastatic disease, and adequate lumbosacral alignment was maintained. The authors conclude that this technique can be safely performed in appropriately selected patients with neoplasms involving L-5.     

Traumatic L5-S1 spondylolisthesis: report of three cases and a review of the literature

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. Received: 1 September 1998 Revised: 28 January 1999 Accepted: 4 February 1999     

Primary lumbosacral stability after open posterior and endoscopic anterior fusion with interbody implants: a roentgen stereophotogrammetric analysis

STUDY DESIGN: After posterior stabilization of the spondylolytic lumbosacral level, mobility of the fused vertebrae could be studied before and after an additional anterior endoscopic interbody fusion using roentgen stereophotogrammetric analysis. OBJECTIVE: To determine the in vivo primary lumbosacral stability of additional anterior interbody fusion after transpedicular screw fixation. SUMMARY OF BACKGROUND DATA: In vitro studies indicate a significant decrease in segmental motion after pedicle screw fixation and additional anterior fusion. Roentgen stereophotogrammetric studies demonstrate the adequacy of transpedicular lumbar instrumentation in posterolateral fusions. There are no studies examining the effect of additional anterior interbody fusion after posterior instrumentation in vivo. METHODS: In this study, 15 patients with low-grade spondylolisthesis at L5-S1 underwent a two-stage open posterior and endoscopic anterior lumbar fusion using carbon fiber (Brantigan I/F) cages. At surgery, tantalum markers were implanted into the fifth lumbar (L5) and the first sacral (S1) vertebra. All the patients were examined by roentgen stereophotogrammetric analysis after the first and second surgical procedures. RESULTS: After implantation of the posterior pedicle system only, the mean intervertebral mobility determined by roentgen stereophotogrammetric analysis was 0.23 mm in the transverse (x), 0.54 mm in the vertical (y), and 1.2 mm in the sagittal (z) axes. After additional anterior endoscopic fusion with carbon cages, the remaining translation between the fused segment L5/S1 decreased to 0.17 mm in the x, 0.16 mm in the y, and 0.44 mm in the z axes. CONCLUSION: Anterior endoscopic lumbosacral fusion significantly increases the primary stability of the posterior fusion with a pedicle system in two axes of motion.     

Lumbosacral metastatic extradural Merkel cell carcinoma causing nerve root compression--case report

A 63-year-old man presented with a rare metastatic Merkel cell carcinoma (MCC) involving the lumbosacral spine and causing nerve root compression. Magnetic resonance (MR) imaging revealed an extradural soft tissue mass at the L5-S1 levels. The tumor was subtotally removed and chemotherapy was administered, but he died of multiple metastases from the primary epigastric tumor. Lumbosacral metastatic epidural tumor can manifest as lumbar disc disease symptoms, but MR imaging can non-invasively and rapidly reveal the presence of spinal epidural tumor and any extension to the spinal canal. Extradural MCC metastasis in the lumbosacral area should be considered in the differential diagnosis of radicular symptoms caused by disc herniation.     

Biomechanical evaluation of methods of posterior stabilization of the spine and posterior lumbar interbody arthrodesis for lumbosacral isthmic spondylolisthesis. A calf-spine model

In order to evaluate biomechanically the efficacy of four types of posterior instrumentation for the stabilization of isthmic spondylolisthesis of the lumbosacral spine, mechanical non-destructive cyclic testing in axial compression, flexion, extension, and rotation was performed on six fresh lumbosacral spines from calves. Each segment contained four motion segments, including the lumbosacral junction. Isthmic spondylolisthesis was created by sectioning the pars interarticularis of the sixth lumbar vertebra and all posterior ligaments between the fifth and sixth lumbar levels. Eight constructs were tested sequentially: (1) the intact spine, (2) the destabilized spine, (3) the spine fixed with Harrington double-distraction rods, (4) the spine treated with transpedicular Cotrel-Dubousset instrumentation with a transverse approximating device, (5) the spine treated with Steffee transpedicular screws and plates, (6) the spine treated with posterior lumbar interbody arthrodesis, (7) the spine treated with Cotrel-Dubousset instrumentation and posterior lumbar interbody arthrodesis, and (8) the spine treated with Steffee instrumentation and posterior lumbar interbody arthrodesis. One motion segment was involved in each construct, except for the spine that was fixed with Harrington instrumentation, which involved three segments. Strain across the supraspinous and anterior longitudinal ligaments was measured with two extensometers that were attached at the spondylolisthetic level and at the intact motion segments adjacent to the fixed level. Harrington instrumentation was the least rigid construct under any type of loading except axial compression (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)