Triangulation of Pedicular Instrumentation

Ruland, Charles M.; McAfee, Paul C.; Warden, Karen E.; Cunningham, Bryan W.

doi:10.1097/00007632-199106001-00019

Cited by 110 publications

(46 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In our study the mean pull-out force was 324±10 N, which is lower than in other studies [2,4,5,7,9,18,19]. Several studies have been performed to investigate the pull-out force of different screws and hooks in thoracic and thoraco-lumbar spine [4,5,18,19], but relatively few authors limited their studies to the thoracic spine [2,7,9]. Berlemann et al [2] tested: -The Universal Spine System (USS) pedicle hook with one screw -A prototype pedicle hook with two screws -The Cotrel-Dubousset (CD) pedicle hook with a screw 5.5 mm long and 3 mm in diameter, and -A pedicle screw 5-mm USS in nine thoracic cadaver spines (T2-T12) with a mean age at time of death of 55.8 years.…”

Section: Discussioncontrasting

confidence: 71%

See 1 more Smart Citation

Biomechanical evaluation of a bipedicular spinal fixation device: three different strength tests

Balabaud

Gallard

Skalli

et al. 2003

European Spine Journal

View full text Add to dashboard Cite

IntroductionDuring the last 40 years, surgical correction techniques applied to spinal deformity have progressed radically. Harrington [8], Luque [14], and then Cotrel and Dubousset [6] added successive contributions to these advances using different approaches. Harrington [8] chose a simple distraction, correcting deformation essentially in the frontal plane. Luque [14] obtained this same distraction by translating the spine toward the rods, which were fixed by laminar wires. Cotrel and Dubousset [6] introduced a threedimensional correction and fixation system using open hooks and rods. During the last few years, developments Abstract Disadvantages of thoracic posterior implants and developments in rod contouring in situ led to the design of a new spinal implant: the bipedicular spinal fixation device (BSF). The BSF is composed of two bifid hooks linked by a compression transverse connector and inserted into the costo-vertebral and costotransverse joints. The aim of this biomechanical study was to determine the loading tolerance of the BSF. Three strength tests -a pull-out test, a lateral load-to-failure test and a uniaxial transversal compression test to failure -were performed using six human thoracic spines on an Instron testing device. Specimen evaluation consisted of: bone mineral density (BMD) measurement with the dual-energy X-ray absorptiometry (DEXA) technique, cortical thickness measurements and a morphometric study. The mean values for load-to-failure in the posterior and lateral tests were 324 N and 400 N respectively. The mean value of the uniaxial compression was 988 N. The mean BMD estimated by DEXA was 0.557 g/cm 2 . The BSF loading tolerance was compatible with the in situ rod contouring technique requirements when we considered posterior and lateral pull-out tests. The transversal compression test determined the appropriate and efficient BSF tightening force.

show abstract

Section: Discussioncontrasting

confidence: 71%

“…Many authors [2,4,5,7,9,19] have shown a linear correlation between BMD estimated by the usual methods (DEXA or CT) and pull-out tests with pedicular screws in thoracic or thoraco-lumbar spines. In contrast, hook pullout forces seem to be independent of the BMD [2,5].…”

Section: Discussionmentioning

confidence: 99%

Biomechanical evaluation of a bipedicular spinal fixation device: three different strength tests

Balabaud

Gallard

Skalli

et al. 2003

European Spine Journal

View full text Add to dashboard Cite

show abstract

“…Multiple factors influence anterior cervical plating strength and stability, including bone mineral density [8,31], bone geometry [27], plate and screw type [31], screw length [5], bone screw interface [10,15,30], and screw orientation [22,28]. Early devices used non-self-tapping screws and required use of a screw that penetrated the posterior cortex of the vertebral body (bicortical purchase) [24,27].…”

Section: Introductionmentioning

confidence: 99%

Experimental in vivo acute and chronic biomechanical and histomorphometrical comparison of self-drilling and self-tapping anterior cervical screws

et al. 2011

View full text Add to dashboard Cite

show abstract

“…Biomechanical advantages include three-column support [1][2][3][4] , possibility of instrumentation in the absence of posterior column integrity [1][2][3][4] and greater rotational stability in the transverse axis 5,6 . An additional benefit from a screwrod construct is the use of cross-links, forming a triangle in the transverse plane, which significantly improves screw pullout strength and rotational and lateral bending stiffness 17,18 . Despite the narrowness of thoracic pedicles, placing screws with diameters greater than the pedicle itself has already been proven safe and efficacious 2 ; and it is known that the greater the minor screw diameter the greater the bending strength and the larger the major screw diameter the greater the pullout strength 19 .…”

Section: Discussionmentioning

confidence: 99%

Free-hand placement of high thoracic pedicle screws with the aid of fluoroscopy: evaluation of positioning by CT scans in a four-year consecutive series

Braga

Morais²,

Vilela

2010

Arq. Neuro-Psiquiatr.

View full text Add to dashboard Cite

Objective: To evaluate the feasibility, safety and accuracy of pedicle screw placement in the upper thoracic spine using the free-hand technique with the aid of fluoroscopy; to analyze the methods used to verify correct screw positioning intra and postoperatively. Method: All patients with instability of the cervicothoracic or upper thoracic spine and at least one screw placed in the segment T1-T6 as part of a posterior construct entered the study. Only C-arm intraoperative fluoroscopy was used to guide screw placement. Results: We obtained excellent positioning in 98.07% of the screws. CT scans precisely demonstrated pedicle wall and anterolateral body violations. There was no hardware failure, no neurological or vascular injury and no loss of alignment during the follow-up period. Conclusion: Pedicle screws can be safely placed in the upper thoracic spine when strict technical principles are followed. Only a CT scan can precisely demonstrate vertebral body and medial pedicle cortical violations. Key words: pedicle screws, transpedicular fixation, thoracic spine, cervicothoracic junction, spinal instability.Colocação de parafusos pediculares na coluna torácica alta utilizando fluoroscopia: avaliação do posicionamento dos parafusos por tomografia computadorizada em uma série de casos durante quatro anos RESUMO Objetivo: Avaliar a factibilidade, segurança e eficácia da colocação de parafusos pediculares na coluna torácia alta utilizando apenas a fluoroscopia; analisar os métodos intra e pós-operatórios de verficação do posicionamento de parafusos. Método: Todos os pacientes com instabilidade da coluna cervico-torácica ou torácica alta e pelo menos um parafuso colocado no segmento T1-T6 foram incluídos no estudo. Apenas fluoroscopia intra-operatória foi utilizada para guiar a colocação dos parafusos. Resultados: Obtivemos excelente posicionamento em 98,07% dos parafusos. TC axial mostrou precisamente violações pediculares e da parede anterolateral do corpo vertebral. Não houve falência do instrumental, lesões neurológicas ou vasculares, ou perda do alinhamento sagital no período de seguimento. Conclusão: Os parafusos pediculares podem ser colocados com segurança na coluna torácica alta desde que técnicas operatórias precisas sejam executadas. Somente a TC pode demonstrar precisamente violações do corpo vertebral e da parede pedicular. Palavras-chave: parafusos pediculares, fixação transpedicular, coluna torácica alta, junção cervico-torácica, instabilidade espinhal.

show abstract

Triangulation of Pedicular Instrumentation

Cited by 110 publications

References 0 publications

Biomechanical evaluation of a bipedicular spinal fixation device: three different strength tests

Biomechanical evaluation of a bipedicular spinal fixation device: three different strength tests

Experimental in vivo acute and chronic biomechanical and histomorphometrical comparison of self-drilling and self-tapping anterior cervical screws

Free-hand placement of high thoracic pedicle screws with the aid of fluoroscopy: evaluation of positioning by CT scans in a four-year consecutive series

Contact Info

Product

Resources

About