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1.
N Engl J Med ; 374(15): 1424-34, 2016 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-27074067

RESUMO

BACKGROUND: The comparative effectiveness of performing instrumented (rigid pedicle screws affixed to titanium alloy rods) lumbar spinal fusion in addition to decompressive laminectomy in patients with symptomatic lumbar grade I degenerative spondylolisthesis with spinal stenosis is unknown. METHODS: In this randomized, controlled trial, we assigned patients, 50 to 80 years of age, who had stable degenerative spondylolisthesis (degree of spondylolisthesis, 3 to 14 mm) and symptomatic lumbar spinal stenosis to undergo either decompressive laminectomy alone (decompression-alone group) or laminectomy with posterolateral instrumented fusion (fusion group). The primary outcome measure was the change in the physical-component summary score of the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36; range, 0 to 100, with higher scores indicating better quality of life) 2 years after surgery. The secondary outcome measure was the score on the Oswestry Disability Index (range, 0 to 100, with higher scores indicating more disability related to back pain). Patients were followed for 4 years. RESULTS: A total of 66 patients (mean age, 67 years; 80% women) underwent randomization. The rate of follow-up was 89% at 1 year, 86% at 2 years, and 68% at 4 years. The fusion group had a greater increase in SF-36 physical-component summary scores at 2 years after surgery than did the decompression-alone group (15.2 vs. 9.5, for a difference of 5.7; 95% confidence interval, 0.1 to 11.3; P=0.046). The increases in the SF-36 physical-component summary scores in the fusion group remained greater than those in the decompression-alone group at 3 years and at 4 years (P=0.02 for both years). With respect to reductions in disability related to back pain, the changes in the Oswestry Disability Index scores at 2 years after surgery did not differ significantly between the study groups (-17.9 in the decompression-alone group and -26.3 in the fusion group, P=0.06). More blood loss and longer hospital stays occurred in the fusion group than in the decompression-alone group (P<0.001 for both comparisons). The cumulative rate of reoperation was 14% in the fusion group and 34% in the decompression-alone group (P=0.05). CONCLUSIONS: Among patients with degenerative grade I spondylolisthesis, the addition of lumbar spinal fusion to laminectomy was associated with slightly greater but clinically meaningful improvement in overall physical health-related quality of life than laminectomy alone. (Funded by the Jean and David Wallace Foundation and others; SLIP ClinicalTrials.gov number, NCT00109213.).


Assuntos
Laminectomia , Vértebras Lombares/cirurgia , Fusão Vertebral , Estenose Espinal/cirurgia , Espondilolistese/cirurgia , Idoso , Idoso de 80 Anos ou mais , Descompressão Cirúrgica , Avaliação da Deficiência , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Reoperação/estatística & dados numéricos , Estenose Espinal/complicações , Espondilolistese/complicações , Resultado do Tratamento
2.
Acta Neurochir Suppl ; 125: 289-294, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30610335

RESUMO

Anterior odontoid screw fixation allows for the internal fixation of unstable odontoid fractures with low morbidity, good fusion rates, and preservation of the atlanto-axial range of motion when applied in appropriate clinical cases. Advances in surgical techniques have allowed for safer, more minimally invasive approaches that reduce the risk of injury to vital prevertebral structures and minimize soft tissue retraction. Moreover, improvements in surgical image guidance technology for spinal surgery that have been applied to odontoid screw placement have helped improve surgeon confidence about exact screw trajectories. In this chapter, we review traditional screw placement techniques and highlight the trends in technical improvements that improve the safety and efficacy of these procedures.


Assuntos
Fixação Interna de Fraturas/métodos , Processo Odontoide/cirurgia , Fraturas da Coluna Vertebral/cirurgia , Fusão Vertebral/métodos , Parafusos Ósseos , Fixação Interna de Fraturas/instrumentação , Fixação Interna de Fraturas/tendências , Humanos , Processo Odontoide/lesões , Fusão Vertebral/instrumentação , Fusão Vertebral/tendências , Resultado do Tratamento
3.
Adv Tech Stand Neurosurg ; 40: 201-13, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24265047

RESUMO

Surgery for conditions in the craniovertebral junction in the pediatric population poses unique challenges. The posterior approach has emerged as the gold standard for arthrodesis in this region. Anterior fixation or decompression also may be indicated. Intraoperative image guidance and neurophysiological monitoring improve the safety and efficacy of these procedures. The specific technical advances in surgery of the craniovertebral junction that have improved patient outcomes are reviewed.


Assuntos
Articulação Atlantoccipital , Descompressão Cirúrgica , Articulação Atlantoccipital/cirurgia , Criança , Humanos
4.
Adv Tech Stand Neurosurg ; 40: 333-53, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24265053

RESUMO

The craniovertebral junction consists of the occiput, atlas, and axis, along with their strong ligamentous attachments. Because of its unique anatomical considerations, trauma to the craniovertebral junction requires specialized care. Children with potential injuries to the craniovertebral junction and cervical spinal cord demand specific considerations compared to adult patients. Prehospital immobilization techniques, diagnostic studies, and spinal injury patterns among young children can be different from those in adults. This review highlights the unique aspects in diagnosis and management of children with real or potential craniovertebral junction injuries.


Assuntos
Vértebras Cervicais , Traumatismos da Coluna Vertebral , Atlas Cervical , Criança , Humanos
5.
J Spinal Disord Tech ; 27(2): 59-63, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22456686

RESUMO

STUDY DESIGN: Retrospective study of computed tomography imaging of patients with thoracolumbar (TL) fractures. OBJECTIVE: To propose an axial model of spinal fractures based on the osteoligamentous continuity of the TL spinal segments in the axial plane and to determine the correlation between the 3-column theory and the proposed axial zone model. SUMMARY OF BACKGROUND DATA: Predicting spinal instability of TL fractures is based on several radiologic and clinical parameters. Efforts to refine fracture classification schemes to better predict instability continue. METHODS: Computed tomography scans of 229 consecutive patients who presented with TL fractures between March 2005 and April 2007 were reviewed. TL fractures were classified according to both the Denis 3-column theory and the proposed axial zone model. The incidence of column and axial zone injuries was determined. On the basis of these results, a treatment algorithm was developed. RESULTS: Zone disruption in surgical fractures was distributed as follows: 24 (96%) involved zone A, 25 (100%) involved zone B, 17 (68%) involved zone C, and 15 (60%) involved zone D. All surgical fractures involved 2 or more zones. Zone B was involved in all surgical fractures. The likelihood of surgical intervention increased as the number of zones increased, especially if the injury was a 2-column or 3-column injury. CONCLUSIONS: The current 3-column theory of spinal stability does not account for the axial component of an injury. Application of our proposed "axial zone model" may enhance the ability to predict stability, depending not only on the number of columns, but also on the number of zones involved in the injuries. Further clinical and biomechanical studies are warranted to validate this model.


Assuntos
Vértebras Lombares/diagnóstico por imagem , Fraturas da Coluna Vertebral/diagnóstico por imagem , Vértebras Torácicas/diagnóstico por imagem , Humanos , Tomografia Computadorizada por Raios X
6.
Brain ; 135(Pt 1): 285-300, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22075067

RESUMO

As a consequence of nascent technology, the 19th century witnessed a profound change in orientation to the nervous system. For example, improved microscopy in the first half of the 19th century allowed high magnification without blurring. The subsequent observation of nucleated cells led to the identification of individual brain cells. Philosophical changes in approach to the natural sciences took their lead from those applied to physical observations. The Ukrainian anatomist and histologist, Vladimir Alekseyevich Betz (1834-94) played a pivotal role in reshaping scientific and philosophical approaches to the brain, connecting cerebral localization, function and brain microstructure. Betz revolutionized methods of cell fixation and staining. Sometimes his efforts yielded enormously complicated technological improvements. Betz's greatest contribution, however, was connecting his discovery of the function of giant pyramidal neurons of the primary motor cortex ('cells of Betz') with the cortical organization. Considering cortical cytoarchitectonics in relation with physiological function, Betz recognized this organization in two areas: motor and sensory. He defined a functional area on histological grounds and thereby opened the way to study precise cortical areas. Betz participated in the scientific transformation of cytoarchitectonics based on macro- and microscopic studies of the cortical surface, enabling him to view the paths of nerve cells in the brain. Betz's influence allowed systemization of scattered scientific findings. The discovery of pyramidal cells was a turning point in the prevailing philosophical and scientific approach to the brain, linking cytoarchitecture, neurophysiology and cerebral localization.


Assuntos
Neurociências/história , Células Piramidais , História do Século XIX , Humanos
7.
Childs Nerv Syst ; 27(7): 1095-100, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21110031

RESUMO

OBJECT: Spinal column trauma is relatively uncommon in the pediatric population, representing 1-2% of all pediatric fractures. However, pediatric spinal injury at more than one level is not uncommon. The purpose of this study was to evaluate the mechanisms and patterns of the injury and factors affecting management and outcomes of pediatric multilevel spine injuries. PATIENTS AND METHODS: Patients with pediatric spine injury (183) were retrospectively reviewed. Patients (28 boys, 20 girls; mean age 12.8 years; range 3 to 16 years) identified with multilevel spinal injuries were 48 (26.2%): 7 patients (14.5%) were between 3 and 9 years of age, and 41 patients (85.5%) were between 9 and 16 years of age. Of the 48 patients, 30 (62.5%) were at contiguous levels and 18 (37.5%) were at noncontiguous. A total of 126 injured vertebrae were diagnosed. The cervical region alone was most frequently (31.2%) involved, and the thoracic region alone was the least frequently involved (12.5%). Overall, 73% of patients were neurologically intact, 4.1% had incomplete spinal cord injury (SCI), and 8.3% had complete SCI. Treatment was conservative in 36 (75%) patients. Surgical treatments were done in 12 patients (25%). Postoperatively, one patient (16.6%) with initial neurologic deficit improved. The overall mortality rate was 6.2%. CONCLUSIONS: Multilevel spine injuries are most common in children between 9 and 16 years of age and are mainly located in the cervical region. The rostral injury was most often responsible for the neurologic deficit. The treatment of multilevel spine injuries should follow the same principles as single level injury, stability and neurologic symptoms indicate the appropriate treatment.


Assuntos
Fraturas da Coluna Vertebral/epidemiologia , Fraturas da Coluna Vertebral/terapia , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Estudos Retrospectivos , Traumatismos da Medula Espinal/epidemiologia , Traumatismos da Medula Espinal/etiologia , Fraturas da Coluna Vertebral/complicações
8.
J Neurosurg Spine ; 34(6): 849-856, 2021 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-33799303

RESUMO

OBJECTIVE: Anterior cervical discectomy and fusion (ACDF) is a common and robust procedure performed on the cervical spine. Literature on ACDF for 4 or more segments is sparse. Increasing the number of operative levels increases surgical complexity, tissue retraction, and risks of complications, particularly dysphagia. The overall risks of these complications and rates of dysphagia are not well studied for surgery on 4 or more segments. In this study, the authors evaluated their institution's perioperative experience with 4- and 5-level ACDFs. METHODS: The authors retrospectively reviewed patients who underwent 4- or 5-level ACDF at their institution over a 6-year period (May 2013-May 2019). Patient demographics, perioperative complications, readmission rates, and swallowing outcomes were recorded. Outcomes were analyzed with a multivariate linear regression. RESULTS: A total of 174 patients were included (167 had 4-level and 7 had 5-level ACDFs). The average age was 60.6 years, and 54.0% of patients (n = 94) were men. A corpectomy was performed in 12.6% of patients (n = 22). After surgery, 56.9% of patients (n = 99) experienced dysphagia. The percentage of patients with dysphagia decreased to 22.8% (37/162) at 30 days, 12.9% (17/132) at 90 days, and 6.3% (5/79) and 2.8% (1/36) at 1 and 2 years, respectively. Dysphagia was more likely at 90 days postoperatively in patients with gastroesophageal reflux (OR 4.4 [95% CI 1.5-12.8], p = 0.008), and the mean (± SD) lordosis change was greater in patients with dysphagia than those without at 90 days (19.8° ± 13.3° vs 9.1° ± 10.2°, p = 0.003). Dysphagia occurrence did not differ with operative implants, including graft and interbody type. The mean length of time to solid food intake was 2.4 ± 2.1 days. Patients treated with dexamethasone were more likely to achieve solid food intake prior to discharge (OR 4.0 [95% CI 1.5-10.6], p = 0.004). Postsurgery, 5.2% of patients (n = 9) required a feeding tube due to severe approach-related dysphagia. Other perioperative complication rates were uniformly low. Overall, 8.6% of patients (n = 15) returned to the emergency department within 30 days and 2.9% (n = 5) required readmission, whereas 1.1% (n = 2) required unplanned return to surgery within 30 days. CONCLUSIONS: This is the largest series of patients undergoing 4- and 5-level ACDFs reported to date. This procedure was performed safely with minimal intraoperative complications. More than half of the patients experienced in-hospital dysphagia, which increased their overall length of stay, but dysphagia decreased over time.

9.
World Neurosurg ; 138: e72-e81, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32036066

RESUMO

OBJECTIVE: Physician burnout in neurosurgery is highly prevalent and occurs most severely during residency. Although earlier assessments have identified stressors contributing to neurosurgery resident burnout, recovery interventions have not been studied extensively. We aimed to characterize burnout patterns and factors contributing to recovery through a single-institution assessment of neurosurgery residents across 4 decades. METHODS: We administered a 59-item questionnaire to all living current and former residents of a large neurosurgical training institution (n = 96). Respondents indicated the timeline of burnout or hardship during residency and evaluated burnout stressors and recovery factors through a 5-point Likert scale and free-text response. RESULTS: The survey response rate was 67% (64 of 96). The overall self-reported burnout rate was 30% (19 of 64). Recent trainees were significantly more likely to report burnout (P < 0.05). Postgraduate year 2 was cited by 66% of respondents as the onset of burnout or hardship. The most common stressors included work-life imbalance (55%) and imbalance of resident duties (33%). The highest-impact recovery factors were end of a rotation or postgraduate year (80%), increased sleep (48%), and meaningful relationships with colleagues (42%). Institution-specific factors, such as outdoor activities (52%) and intraprogram social events (34%), were also influential in recovery. In free-text responses, respondents identified a strong sense of mission in neurosurgical training as a central driver of recovery to wellness. CONCLUSIONS: Institutional support structures promoting mentorship and camaraderie are actionable methods to encourage resident burnout recovery. This study serves as a model for other programs to identify their "critical periods" of burnout and effective wellness interventions.


Assuntos
Esgotamento Profissional , Neurocirurgia/educação , Adulto , Idoso , Esgotamento Profissional/epidemiologia , Esgotamento Profissional/etiologia , Esgotamento Profissional/terapia , Feminino , Humanos , Internato e Residência , Masculino , Mentores , Pessoa de Meia-Idade , Prevalência , Inquéritos e Questionários
10.
J Neurosurg Spine ; 11(3): 338-43, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19769516

RESUMO

OBJECT: The small diameter of the pedicle can make C-7 pedicle screw insertion dangerous. Although transfacet screws have been studied biomechanically when used in pinning joints, they have not been well studied when used as part of a C7-T1 screw/rod construct. The authors therefore compared C7-T1 fixation using a C-7 transfacet screw/T-1 pedicle screw construct with a construct composed of pedicle screws at both levels. METHODS: Each rigid posterior screw/rod construct was placed in 7 human cadaveric C6-T2 specimens (14 total). Specimens were tested in normal condition, after 2-column instability, and once fixated. Nondestructive, nonconstraining pure moments (maximum 1.5 Nm) were applied to induce flexion, extension, lateral bending, and axial rotation while recording 3D motion optoelectronically. The entire construct was then loaded to failure by dorsal linear force. RESULTS: There was no significant difference in angular range of motion between the 2 instrumented groups during any loading mode (p > 0.11, nonpaired t-tests). Both constructs reduced motion to < 2 degrees in any direction and allowed significantly less motion than in the normal condition. The C-7 facet screw/T-1 pedicle screw construct allowed a small but significantly greater lax zone than the pedicle screw/rod construct during lateral bending, and it failed under significantly less load than the pedicle screw/rod construct (p < 0.001). CONCLUSIONS: When C-7 transfacet screws are connected to T-1 pedicle screws, they provide equivalent stability of constructs formed by pedicle screws at both levels. Although less resistant to failure, the transfacet screw construct should be a viable alternative in patients with healthy bone.


Assuntos
Parafusos Ósseos , Vértebras Cervicais/cirurgia , Fixação de Fratura , Amplitude de Movimento Articular/fisiologia , Articulação Zigapofisária/fisiopatologia , Articulação Zigapofisária/cirurgia , Idoso , Fenômenos Biomecânicos/fisiologia , Cadáver , Análise de Falha de Equipamento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Suporte de Carga/fisiologia
11.
J Neurosurg Spine ; 10(2): 171-6, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19278333

RESUMO

OBJECT: Sonic hedgehog (Shh) is a glycoprotein molecule that upregulates the transcription factor Gli1. The Shh protein plays a critical role in the proliferation of endogenous neural precursor cells when directly injected into the spinal cord after a spinal cord injury in adult rodents. Small-molecule agonists of the hedgehog (Hh) pathway were used in an attempt to reproduce these findings through intravenous administration. METHODS: The expression of Gli1 was measured in rat spinal cord after the intravenous administration of an Hh agonist. Ten adult rats received a moderate contusion and were treated with either an Hh agonist (10 mg/kg, intravenously) or vehicle (5 rodents per group) 1 hour and 4 days after injury. The rats were killed 5 days postinjury. Tissue samples were immediately placed in fixative. Samples were immunohistochemically stained for neural precursor cells, and these cells were counted. RESULTS: Systemic dosing with an Hh agonist significantly upregulated Gli1 expression in the spinal cord (p < 0.005). After spinal contusion, animals treated with the Hh agonist had significantly more nestin-positive neural precursor cells around the rim of the lesion cavity than in vehicle-treated controls (means +/- SDs, 46.9 +/- 12.9 vs 20.9 +/- 8.3 cells/hpf, respectively, p < 0.005). There was no significant difference in the area of white matter injury between the groups. CONCLUSIONS: An intravenous Hh agonist at doses that upregulate spinal cord Gli1 transcription also increases the population of neural precursor cells after spinal cord injury in adult rats. These data support previous findings based on injections of Shh protein directly into the spinal cord.


Assuntos
Contusões/patologia , Contusões/terapia , Proteínas Hedgehog/agonistas , Traumatismos da Medula Espinal/patologia , Traumatismos da Medula Espinal/terapia , Células-Tronco/efeitos dos fármacos , Animais , Proliferação de Células/efeitos dos fármacos , Contusões/metabolismo , Proteínas Hedgehog/administração & dosagem , Injeções Intraperitoneais , Injeções Intravenosas , Proteínas de Filamentos Intermediários/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Nestina , Ratos , Ratos Sprague-Dawley , Traumatismos da Medula Espinal/metabolismo , Células-Tronco/fisiologia , Vértebras Torácicas , Proteína GLI1 em Dedos de Zinco
12.
J Neurosurg Spine ; 31(6): 775-785, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31786543

RESUMO

Insight into the historic contributions made to modern-day spine surgery provides context for understanding the monumental accomplishments comprising current techniques, technology, and clinical success. Only during the last century did surgical growth occur in the treatment of spinal disorders. With that growth came a renaissance of innovation, particularly with the evolution of spinal instrumentation and fixation techniques. In this article, the authors capture some of the key milestones that have led to the field of spine surgery today, with an emphasis on the historical advances related to instrumentation, navigation, minimally invasive surgery, robotics, and neurosurgical training.


Assuntos
Neurocirurgia/história , Procedimentos Neurocirúrgicos/história , Doenças da Coluna Vertebral/cirurgia , Coluna Vertebral/cirurgia , História do Século XIX , História do Século XX , História do Século XXI , Humanos , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Procedimentos Neurocirúrgicos/métodos , Cirurgia Assistida por Computador
13.
Neurosurg Focus ; 25(5): E12, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18980472

RESUMO

OBJECT: Venous stasis and intrathecal hypertension are believed to play a significant role in the hypoperfusion present in the spinal cord following injury. Lowering the intrathecal pressure via cerebrospinal fluid (CSF) drainage has been effective in treating spinal cord ischemia during aorta surgery. The purpose of the present study was to determine whether CSF drainage increases spinal cord perfusion and improves outcome after spinal injury in an animal model. METHODS: Anesthetized adult rabbits were subjected to a severe contusion spinal cord injury (SCI). Cerebrospinal fluid was then drained via a catheter to lower the intrathecal pressure by 10 mm Hg. Tissue perfusion was assessed at the site of injury, and values obtained before and after CSF drainage were compared. Two other cohorts of animals were subjected to SCI: 1 group subsequently underwent CSF drainage and the other did not. Results of histological analysis, motor evoked potential and motor function testing were compared between the 2 cohorts at 4 weeks postinjury. RESULTS: Cerebrospinal fluid drainage led to no significant improvement in spinal cord tissue perfusion. Four weeks after injury, the animals that underwent CSF drainage demonstrated significantly smaller areas of tissue damage at the injury site. There were no differences in motor evoked potentials or motor score outcomes at 4 weeks postinjury. CONCLUSIONS: Cerebrospinal fluid drainage effectively lowers intrathecal pressure and decreases the amount of tissue damage in an animal model of spinal cord injury. Further studies are needed to determine whether different draining regimens can improve motor or electrophysiological outcomes.


Assuntos
Líquido Cefalorraquidiano , Drenagem , Perfusão/métodos , Traumatismos da Medula Espinal/fisiopatologia , Traumatismos da Medula Espinal/terapia , Animais , Pressão Sanguínea/fisiologia , Pressão do Líquido Cefalorraquidiano/fisiologia , Modelos Animais de Doenças , Potencial Evocado Motor , Injeções Espinhais/métodos , Laminectomia/métodos , Coelhos
14.
Neurosurg Focus ; 25(5): E3, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18980477

RESUMO

OBJECT: Axonal regeneration may be hindered following spinal cord injury (SCI) by a limited immune response and insufficient macrophage recruitment. This limitation has been partially surmounted in small-mammal models of SCI by implanting activated autologous macrophages (AAMs). The authors sought to replicate these results in a canine model of partial SCI. METHODS: Six dogs underwent left T-13 spinal cord hemisection. The AAMs were implanted at both ends of the lesion in 4 dogs, and 2 other dogs received sham implantations of cell media. Cortical motor evoked potentials (MEPs) were used to assess electrophysiological recovery. Functional motor recovery was assessed with a modified Tarlov Scale. After 9 months, animals were injected with wheat germ agglutinin-horseradish peroxidase at L-2 and killed for histological assessment. RESULTS: Three of the 4 dogs that received AAM implants and 1 of the 2 negative control dogs showed clear recovery of MEP response. Behavioral assessment showed no difference in motor function between the AAM-treated and control groups. Histological investigation with an axonal retrograde tracer showed neither local fiber crossing nor significant uptake in the contralateral red nucleus in both implanted and negative control groups. CONCLUSIONS: In a large-animal model of partial SCI treated with implanted AAMs, the authors saw no morphological or histological evidence of axonal regeneration. Although they observed partial electrophysiological and functional motor recovery in all dogs, this recovery was not enhanced in animals treated with implanted AAMs. Furthermore, there was no morphological or histological evidence of axonal regeneration in animals with implants that accounted for the observed recovery. The explanation for this finding is probably multifactorial, but the authors believe that the AAM implantation does not produce axonal regeneration, and therefore is a technology that requires further investigation before it can be clinically relied on to ameliorate SCI.


Assuntos
Imunoterapia/métodos , Macrófagos/imunologia , Traumatismos da Medula Espinal/fisiopatologia , Traumatismos da Medula Espinal/cirurgia , Animais , Técnicas de Cultura de Células , Modelos Animais de Doenças , Cães , Estimulação Elétrica , Eletrofisiologia , Potencial Evocado Motor/fisiologia , Feminino , Lateralidade Funcional , Laminectomia/métodos , Regeneração Nervosa , Recuperação de Função Fisiológica , Índice de Gravidade de Doença , Fatores de Tempo , Transplante Autólogo/métodos , Conjugado Aglutinina do Germe de Trigo-Peroxidase do Rábano Silvestre
15.
Neurosurg Focus ; 24(3-4): E20, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18341397

RESUMO

The development of an acute traumatic spinal cord injury (SCI) inevitably leads to a complex cascade of ischemia and inflammation that results in significant scar tissue formation. The development of such scar tissue provides a severe impediment to neural regeneration and healing with restoration of function. A multimodal approach to treatment is required because SCIs occur with differing levels of severity and over different lengths of time. To achieve significant breakthroughs in outcomes, such approaches must combine both neuroprotective and neuroregenerative treatments. Novel techniques modulating endogenous stem cells demonstrate great promise in promoting neuroregeneration and restoring function.


Assuntos
Protocolos Clínicos , Traumatismos da Medula Espinal/terapia , Transplante de Células-Tronco/métodos , Células-Tronco/fisiologia , Animais , Humanos , Regeneração Nervosa/fisiologia , Recuperação de Função Fisiológica , Traumatismos da Medula Espinal/patologia , Traumatismos da Medula Espinal/fisiopatologia
16.
J Neurosurg Spine ; 8(1): 44-51, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18173346

RESUMO

OBJECT: An in vitro flexibility experiment was performed to compare the biomechanical stability of asymmetrical lumbar pedicle screw fixation (longer hardware attached ipsilaterally to a 1-sided lesion), short and long fixation, and fixation with and without interconnection to the involved vertebra. METHODS: Seven human cadaveric specimens (T12-S1) were studied intact; after simulated unilateral lesions were created at L2-3 and L3-4, the segments were stabilized by 1) L2-4 unilateral fixation (L-3 excluded), 2) L2-4 bilateral fixation (L-3 included contralaterally), 3) L2-5 unilateral fixation (L-3 excluded), 4) L2-5 fixation ipsilateral (L-3 excluded) and L2-4 fixation contralateral (L-3 included), 5) L2-5 bilateral fixation (L-3 included contralaterally), and 6) L2-5 bilateral fixation (L-3 excluded). The testing order varied among specimens. Angular range of motion (ROM) and lax zone were recorded optically while loading to 6.0 Nm was created with nonconstraining pure moments. RESULTS: Unilateral short fixation provided significantly worse stabilization than any other construct tested in all loading modes (p < 0.05, repeated-measures analysis of variance). There was a mean 56% reduction in ROM across the lesion after adding 1 additional level rostrally and caudally. Asymmetrical long/short stabilization provided similar stability to symmetrical long stabilization. Minimal additional stability was gained by including L-3 in the long bilateral fixation construct. CONCLUSIONS: Unilateral fixation is inadequate for stabilizing a 2-level unilateral lesion. Bilateral fixation, whether symmetrical or asymmetrical, provides good stabilization for this injury. It is not important for stability to include the level of the lesion within the long construct contralaterally.


Assuntos
Parafusos Ósseos , Vértebras Lombares/cirurgia , Doenças da Coluna Vertebral/cirurgia , Fusão Vertebral/métodos , Adulto , Idoso , Fenômenos Biomecânicos , Cadáver , Desenho de Equipamento , Feminino , Humanos , Imageamento Tridimensional , Fixadores Internos , Masculino , Teste de Materiais , Pessoa de Meia-Idade , Maleabilidade , Amplitude de Movimento Articular/fisiologia , Fusão Vertebral/instrumentação , Torque
17.
J Neurosurg Spine ; 9(2): 200-6, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18764755

RESUMO

OBJECT: Lateral mass screws are traditionally used to fixate the subaxial cervical spine, while pedicle screws are used in the thoracic spine. Lateral mass fixation at C-7 is challenging due to thin facets, and placing pedicle screws is difficult due to the narrow pedicles. The authors describe their clinical experience with a novel technique for transfacet screw placement for fixation at C-7. METHODS: A retrospective chart review was undertaken in all patients who underwent transfacet screw placement at C-7. The technique of screw insertion was the same for each patient. Polyaxial screws between 8- and 10-mm-long were used in each case and placed through the facet from a perpendicular orientation. Postoperative radiography and clinical follow-up were analyzed for aberrant screw placement or construct failure. RESULTS: Ten patients underwent C-7 transfacet screw placement between June 2006 and March 2007. In all but 1 patient screws were placed bilaterally, and the construct lengths ranged from C-3 to T-5. One patient with a unilateral screw had a prior facet fracture that precluded bilateral screw placement. There were no intraoperative complications or screw failures in these patients. After an average of 6 months of follow-up there were no hardware failures, and all patients showed excellent alignment. CONCLUSIONS: The authors present the first clinical demonstration of a novel technique of posterior transfacet screw placement at C-7. These results provide evidence that this technique is safe to perform and adds stability to cervicothoracic fixation.


Assuntos
Parafusos Ósseos , Vértebras Cervicais/cirurgia , Idoso , Feminino , Humanos , Instabilidade Articular/cirurgia , Masculino , Pessoa de Meia-Idade , Doenças da Coluna Vertebral/cirurgia , Fusão Vertebral/instrumentação , Fusão Vertebral/métodos
18.
J Neurosurg Spine ; 8(2): 143-52, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18248286

RESUMO

OBJECT: The stability provided by 3 occipitoatlantal fixation techniques (occiput [Oc]-C1 transarticular screws, occipital keel screws rigidly interconnected with C-1 lateral mass screws, and suboccipital/sublaminar wired contoured rod) were compared. METHODS: Seven human cadaveric specimens received transarticular screws and 7 received occipital keel-C1 lateral mass screws. All specimens later underwent contoured rod fixation. All conditions were studied with and without placement of a structural graft wired between the skull base and C-1 lamina. Specimens were loaded quasistatically using pure moments to induce flexion, extension, lateral bending, and axial rotation while recording segmental motion optoelectronically. Flexibility was measured immediately postoperatively and after 10,000 cycles of fatigue. RESULTS: Application of Oc-C1 transarticular screws, with a wired graft, reduced the mean range of motion (ROM) to 3% of normal. Occipital keel-C1 lateral mass screws (also with graft) offered less stability than transarticular screws during extension and lateral bending (p < 0.02), reducing ROM to 17% of normal. The wired contoured rod reduced motion to 31% of normal, providing significantly less stability than either screw fixation technique. Fatigue increased motion in constructs fitted with transarticular screws, keel screws/lateral mass screw constructs, and contoured wired rods, by means of 19, 5, and 26%, respectively. In all constructs, adding a structural graft significantly improved stability, but the extent depended on the loading direction. CONCLUSIONS: Assuming the presence of mild C1-2 instability, Oc-C1 transarticular screws and occipital keel-C1 lateral mass screws are approximately equivalent in performance for occipitoatlantal stabilization in promoting fusion. A posteriorly wired contoured rod is less likely to provide a good fusion environment because of less stabilizing potential and a greater likelihood of loosening with fatigue.


Assuntos
Articulação Atlantoccipital/fisiopatologia , Articulação Atlantoccipital/cirurgia , Parafusos Ósseos , Luxações Articulares/cirurgia , Amplitude de Movimento Articular/fisiologia , Fusão Vertebral/métodos , Fenômenos Biomecânicos , Cadáver , Feminino , Humanos , Luxações Articulares/fisiopatologia , Masculino , Pessoa de Meia-Idade , Fusão Vertebral/instrumentação
19.
J Neurosurg Spine ; 9(1): 40-7, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18590409

RESUMO

OBJECT: The authors conducted a study to evaluate the clinical characteristics and surgical outcomes in patients with spinal schwannomas and without neurofibromatosis (NF). METHODS: The data obtained in 128 patients who underwent resection of spinal schwannomas were analyzed. All cases with neurofibromas and those with a known diagnosis of NF Type 1 or 2 were excluded. Karnofsky Performance Scale (KPS) scores were used to compare patient outcomes when examining the anatomical location and spinal level of the tumor. The neurological outcome was further assessed using the Medical Research Council (MRC) muscle testing scale. RESULTS: Altogether, 131 schwannomas were treated in 128 patients (76 males and 52 females; mean age 47.7 years). The peak prevalence is seen between the 3rd and 6th decades. Pain was the most common presenting symptom. Gross-total resection was achieved in 127 (97.0%) of the 131 lesions. The nerve root had to be sacrificed in 34 cases and resulted in minor sensory deficits in 16 patients (12.5%) and slight motor weakness (MRC Grade 3/5) in 3 (2.3%). The KPS scores and MRC grades were significantly higher at the time of last follow-up in all patient groups (p = 0.001 and p = 0.005, respectively). CONCLUSIONS: Spinal schwannomas may occur at any level of the spinal axis and are most commonly intradural. The most frequent clinical presentation is pain. Most spinal schwannomas in non-NF cases can be resected totally without or with minor postoperative deficits. Preoperative autonomic dysfunction does not improve significantly after surgical management.


Assuntos
Neurilemoma/cirurgia , Neoplasias da Coluna Vertebral/cirurgia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Humanos , Masculino , Microcirurgia , Pessoa de Meia-Idade , Neurilemoma/complicações , Dor/etiologia , Complicações Pós-Operatórias , Transtornos de Sensação/etiologia , Neoplasias da Coluna Vertebral/complicações , Resultado do Tratamento
20.
J Neurosurg ; 106(6 Suppl): 426-33, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17566397

RESUMO

OBJECT: The authors evaluated the mechanisms and patterns of thoracic, lumbar, and sacral spinal injuries in a pediatric population as well as factors affecting the management and outcome of these injuries. METHODS: The records of 89 patients (46 boys and 43 girls; mean age 13.2 years, range 3-16 years) with thoracic, lumbar, or sacral injuries were reviewed. Motor vehicle accidents were the most common cause of injury. Eighty-two patients (92.1%) were between 10 and 16 years old, and seven (7.9%) were between 3 and 9 years old. Patient injuries included fracture (91%), fracture and dislocation (6.7%), dislocation (1.1%), and ligamentous injury (1.1%). The L2-5 region was the most common injury site (29.8%) and the sacrum the least common injury site (5%). At the time of presentation 85.4% of the patients were neurologically intact, 4.5% had incomplete injuries, and 10.1% had complete injuries. Twenty-six percent of patients underwent surgery for their injuries whereas 76% received nonsurgical treatment. In patients treated surgically, an anterior approach was used in six patients (6.7%), a posterior approach in 16 (18%), and a combined approach in one (1.1%). Postoperatively, six patients (26.1%) with neurological deficits improved, one of whom recovered fully from an initially complete injury. CONCLUSIONS: Thoracic and lumbar spine injuries were most common in children older than 9 years. Multilevel injuries were common and warranted imaging evaluation of the entire spinal column. Most patients were treated conservatively. The prognosis for neurological recovery is related to the initial severity of the neurological injuries. Some pediatric patients with devastating spinal cord injuries can recover substantial neurological function.


Assuntos
Vértebras Lombares/lesões , Sacro/lesões , Traumatismos da Coluna Vertebral/epidemiologia , Traumatismos da Coluna Vertebral/terapia , Vértebras Torácicas/lesões , Acidentes de Trânsito , Adolescente , Distribuição por Idade , Criança , Pré-Escolar , Feminino , Humanos , Luxações Articulares/epidemiologia , Ligamentos/lesões , Imageamento por Ressonância Magnética , Masculino , Doenças do Sistema Nervoso/etiologia , Procedimentos Neurocirúrgicos , Prognóstico , Fraturas da Coluna Vertebral/epidemiologia , Fraturas da Coluna Vertebral/terapia , Traumatismos da Coluna Vertebral/complicações , Traumatismos da Coluna Vertebral/etiologia , Tomografia Computadorizada por Raios X , Resultado do Tratamento
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