ISSN:0362-2436    

出版商:OVID    

年代:1995

数据来源: OVID

ISSN:0362-2436    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Study DesignTissue from the pars defects of six adult patients with symptomatic spondyloiysis and spondylolisthesis was obtained at surgery. A histologic study was conducted to identify and characterize neural elements in this tisse.ObjectivesTo determine if nociceptive nerve endings were present within the pars defect of patients with symptomatic spondylolysis.Summary of Background DataThe origin of back pain in patients with spondyloysis remains uncertain. The defect in the pars interaticularis has been implicated as a possible pain source.MethodsThe soft tissue from the pars defect was obtained at surgery. A modified gold chloride stain was used to prepare the tissue for histologic examination. Tissue blocks were sectioned and studied under light microscopy.ResultsNeural elements were found in all specimens examined. Free nerve endings believed to have nocieptive function were identified in all specimens, The density of neural elements varied between specimens.ConclsionsThe finding of neural elements, including free nerve endings within the pars defect tissue, suggests that the pars defect may be a source of back pain in some patients with symptomatic spondyloysis.

ISSN:0362-2436    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Study DesignControlled correction of scoliosis in a rat model was used to assess the accuracy of intraperative motor-evoked potential monitoring.ObjectivesThe purpose of this study was to develop a model in which motor-evoked potential changes could be compared with neurologic function after surgery, such that a threshold for responding to motor-evoked potential changes may be established.Summary of Background DataIntraoperative motor-evoked potential monitoring has become technically feasible. Clinical application now depends on the development of useful interpretation parameters and correlation with neurologic sequelae.MethodsExperimental scoliosis was produced in 30 rat pups. After growth, the rats underwent correction of their scoliosis by distraction. Changes in toMMEP onset latency and amplitude were measured. Distraction was applied either until a 10% delay in tcMMEP onset latency (Group 1), until tcMMEP responses were ablated (Group 2) or for 10 minutes after the loss of transcranial magnetic stimulation response (Group 3).ResultsIn Group 1 (n = 10), all animals had tcMMEP with normal onset latency and normal neurologic examinations 24 hours after surgery. In Group 2 (n = 10), tcMMEP were normal in four rats, markedly delayed in three rats, and absent in three rats 24 hours after surgery. Neurologic examination was normal in the four rats with normal tcMMEP. Moderate deficit was noted in two of the three rats with prolonged onset latency 24 hours after surgery; the third was intact, Moderate neurologic injury was noted in two of three rats with absent tcMMEP 24 hours after surgery; the third rat was paralyzed. In Group 3 (n = 10), vertebral dislocation was noted on lateral radiographs in eight of 10 animals. Twenty-four hours after surgery, tcMMEP remained absent, and paralysis was noted in the eight rates of 10 animals. Twenty-four hours after surgery, tcMMEP remained absent, and paralysis was noted in the eight rats with dislocation. The two rats without dislocation had delayed tcMMEP but some return of neurologic function.ConclusionsComparison of the three groups shows a significant correlation between tcMMEP and endpoint neurologic outcome. None of the rats in Group 1 had a neurologic deficit after surgery as opposed to five of 10 rats in Group 2 and 10 of 10 rats in Group 3 with significant neurologic injury. These findings suggest that a 10% delay in onset latency would be an appropriate threshold for responding to changes in tcMMEP

ISSN:0362-2436    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Study DesignThe authors investigate the usefulness of magnetic resonance imaging in differentiating benign versus malignan compression fractures by reviewing patients and a fracture model in a canine model.ObjectivesTo determine the sensitivity and specificity of magnetic resonance imaging in differentiating benign versus malignant compression fractures of the spine and to obtain distinguishing features in magnetic resonance imaging.Summary of Background DataThe differentiation between benign and abnormal compression fractures of the thoracolumbar spine has important implications regarding patient treatment and prognosis. Plain radiographs, bone scans, and computed tomography are not accurate imaging modalities for this purpose.MethodsMagnetic resonance imaging scans of 22 patients with confirmed lesions of the thoracolumbar spine were studied. There were 11 malignant and 11 benign lesions. Two experienced neuroadiologists blindly reviewed the magnetic resonance imaging scans and determined benign or malignant lesions. A canine study was performed to simulate a compression fracture model with a vertebral osteotomy in two dogs, and serial contrast-enhanced magnetic resonance imaging scans were performed 15, 30, 60 and 90 days after surgery.ResultsThe correct interpretation between two neuroradiologists was 77% and 95%. The combined sensitivity rate was 88.5%, and the specificity rate was 89.5%. Magnetic resonance imaging reliably distinguished beningn versus malignant lesions based on the anatomic distribution and intensity of signal changes of bone and adjacent tissues, contrast enhancement characteristics, and changes over time. Only one malignant lesion was misinterpreted by both neuroradiologists as benign, whereas there was one additional missed malignant lesion and three misinterpreted benign lesions by one radiologist. In the canine study, signal changes and enhancement were found 60 days after surgery, but no signal changes or enhancement were noted on the scan 90 days after surgery.ConclusionsMagnetic resonance imaging scans can detect malignant vertebral lesions early, but acute healing compression fractures may mimic the findings of metastatic lesions. The use of contrast-enhanced magnetic resonance imaging scans and serial magnetic resonance imagings are helpful for additional differentiation between benign and malignant compression fractures. In addition to magnetic resonance imaging scans, other diagnostic tests and clinical findings should be correlated before biopsy or surgery of the suspected lesion.

ISSN:0362-2436    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Study DesignA review of a cohort of 310 consecutive patients who underwent anterior spinal fusion was performed to evaluate the accuracy of hospital ICD-9-CM complication coding.Objectives.To better understand the clinical significance of conclusions suggested by studies that rely on electronic administrative databases for their data source.Summary of Background Data.Despite their availability, there have been no studies to date that have evaluated the accuracy of ICD-9-CM administrative databases as they relate to the actual clinical experience in spinal procedures.Methods.A physician and a research technician independently reviewed the primary medical records for the occurrence of complications. This data was compared with the hospital-acquired ICD-9-CM coded complications.ResultsThe physician reviewer identified 152 complications in 119 patients, with 32 different types of complications. The research abstracter identified 175 complications in 130 patients, with 34 different types of complications identified. Hospital ICD-9-CM coding identified 105 complications in 80 patients, including only 11 different ICD-9-CM codes. Overall, 27% of ICD-9-CM complication codes were listed as “unspecified or unclassified complications, reactions, or misadventures,” and contained no meaningful clinical information. Cardiac and pulmonary complications were overestimated and wound in fections and genitourinary and gastrointestinal complications were underestimated by ICD-9-CM coding.Conclusions.Studies of complications of spinal procedures using data derived from hospital ICD-9-CM Complication codes may be intrinsically flawed because the data available to researchers from these electronic databases may be inaccurate.

ISSN:0362-2436    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Study Design.The biomechanics of three different instrumentation constructs applied at the destabilized cervicothoracic junction were evaluated.Objectives.To find an efficient way in restoring stability of the cervicothoracic junction in cases with and without laminectomy.Summary of Background Data.Different instrumentation techniques have been evaluated biomechanically and used clinically for managing instabilities between and used clinically for managing instabilities between the fourth and sixth cervical vertebrae. These constructs have not been evaluated at the cervicothoracic junction.Methods.Six human spines were tested nondestructively in axial torsion, flexion, and extension with the C6-T2 motion segments left unconstrained. The three-dimensional displacements and rotations between C7 and T1 vertebrae were measured using a sonic digitizer. After intact testing, a distractive-flexion Stage 3 cervical spinal injury was simulated surgically between C7 and T1. The specimens underwent sequential instrumentation and mechanical testing with three constructs: posterior Synthes lateral mass plate, posterior pediatric Cotrel-Dubousset rod system with lamina hooks and a crosslink, and anterior Synthes cervical locking plate.ResultsPosterior stabilization techniques had statistically more stiffness than anterior plates. The Cotrel-Dubousset system offered the largest stiffness ratio(instrumented/intact) in flexion, extension, and rotation. There was no statistical difference between posterior plates and Cotrel-Dubousset instrumentation. The stiffness of the anterior plate did not differ significantly from the intact spine.ConclusionOur data show that instability of the cervicothoracic junction can be efficiently restored by either anterior plates, posterior plates, or posterior hookrod constructs (Cotrel-Dubousset). Posterior constructs showed increased stiffness over anterior plates.

ISSN:0362-2436    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Study Design.This study evaluated clinical and magnetic resonance imaging differences of patients treated surgically for lumbar disc herniation. Clinical follow-up and magnetic resonance imaging evaluation of epidural fibrosis were used to assess patient outcome.Objectives.The purpose of this study was to evaluate the difference in clinical outcome with either free-fat graft, Golfoam, or no interposition membrane placed in the laminectomy defect after nerve root decompression.Summary of Background Data.Epidural fibrosis has been considered a cause of recurrent symptoms after lumbar laminectomy, and numerous materials have been evaluated for prophylaxis of the “laminectomy membrane.” These have been mainly histologic and animal studies with no data correlating clinical symptoms and postoperative epidural scar formation.Methods.One hundred fifty-six patients who were treated surgically for lumbar disc herniation were randomly assigned to one of three groups and followed prospectively for at least 1 year. Thirty-three of these patients were received magnetic resonance imaging evaluations after 6 months by an idependent radiologist who graded the amount of epidural scar formation. The patients were assessed at 1 year and given a rating of excellent, good, fair, or poor, and the scar was graded as none, minimal, or moderate.Results.Although 97% of all patients improved, 83% were rated excellent or good. There were no statistical differences between the three groups clinically and radiographically. Patients with workers compensation had a statistically significant lower success rate (P <0.001).Conclusions.Clinical outcome after lumbar disc surgery does not correlate with the use or type of interposition membrane used to prevent epidural fibrosis.

ISSN:0362-2436    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Study Design.Patients presenting with L5-S1 anterior column disease with or without herniation into the spinal canal but without stenosis underwent magnetic resonance imaging screening before surgery to determine surgical suitability for laparoscopic anterior lumbar interbody fusion relative to the aortic bifuraction and approach to the disc space.Objectives.To analyze and evaluate the laparoscopic approach, technique, and benefit of anterior lumbar discectomy and interbody fusion by distraction and compression-loading of autograft only as compared with cage-spacer-enhanced autograft fusion.Summary of Background Data.Advancement in minimally invasive spine surgery techniques has provided options with less morbidity for posterior lumbar procedures. General surgical advancements in laparoscopy and advantages of traditional anterior lumbar interbody fusion, including restoration of disc height and exposure for safe nerve decompression, provided a basis for an integrated procedure that would address anterior column abnormality with low surgical morbidity.Methods.Five patients underwent technically successful laparoscopic anterior lumbar interbody fusion with approach to the disc space by an experienced laparoscopic general surgeon. A sixth patient in the study group was unable to undergo laparoscopic fusion because of an iliac vein tear during the surgical approach. After the approach, a spine surgeon followed with complete manual discectomy and interbody autogenous fusion laparoscopically. Two to three Cloward-type dowels were obtained by separate incision from the anterior iliac crest.Results.All patients by 6− month follow-up examination were clinically fused with no motion on flexion extension radiographs. One patient had slight anterior retropulsion of one dowel without the necessity of reoperation.Conclusions.Laparoscopic L5-S1 anterior lumbar interbody arthrodesis may represent a viable option for patients with abnormality, including anterior column and degenerative disc disease.

ISSN:0362-2436    

出版商:OVID    

年代:1995

数据来源: OVID

ISSN:0362-2436    

出版商:OVID    

年代:1995

数据来源: OVID