Comparing the Kinematics of Lumbar Spine: Anatomic Facet Replacement System (AFRS™) vs. Rigid Fixation System

2007 ◽  
Author(s):  
A. Mehta ◽  
A. Faizan ◽  
A. Kiapour ◽  
J. Jangra ◽  
V. K. Goel ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Pedicle Screw ◽  
Facet Joint ◽  
Donor Site ◽  
Rigid Fixation ◽  
Adjacent Level ◽  
Donor Site Pain ◽  
Rigid Rod ◽  
Replacement System ◽  
Fixation System

Problems associated with spinal fusion such as adjacent level degeneration and donor site pain have shifted the focus to motion preservation technologies. The Anatomic Facet Replacement System (AFRS™) (Facet Solutions, Inc., Logan, Utah) attempts to address posterior lumbar spine pathologies while preserving stability and natural biomechanics thereby mitigating any potential adjacent level effects resulting from the reduction or elimination of motion as seen in semi-constrained dynamic stabilization and fusion devices. The AFRS™ is comprised of a precision instrumentation set whose design is based upon a comprehensive CT morphology study of the facet joint. It utilizes traditional pedicle screw fixation of its superior and inferior facet implants and is manufactured from a wear resistant alloy called cobalt-chromium-molybdenum. An experimentally validated finite element model was used for the quantification of facet loads and stresses in various components of the facet replacement system and also in the model stabilized using a pedicle screw rigid rod fixation system.

scholarly journals Influence of posterior pedicle screw fixation at L4–L5 level on biomechanics of the lumbar spine with and without fusion: a finite element method

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Emre Sengul ◽  
Ramazan Ozmen ◽  
Mesut Emre Yaman ◽  
Teyfik Demir
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Pedicle Screw ◽  
Posterior Lumbar Interbody Fusion ◽  
Adjacent Segment ◽  
Fe Model ◽  
Lateral Bending ◽  
Adjacent Level ◽  
Before And After ◽  
Fixation System

Abstract Background Posterior pedicle screw (PS) fixation, a common treatment method for widespread low-back pain problems, has many uncertain aspects including stress concentration levels, effects on adjacent segments, and relationships with physiological motions. A better understanding of how posterior PS fixation affects the biomechanics of the lumbar spine is needed. For this purpose, a finite element (FE) model of a lumbar spine with posterior PS fixation at the L4–L5 segment level was developed by partially removing facet joints (FJs) to imitate an actual surgical procedure. This FE study aimed to investigate the influence of the posterior PS fixation system on the biomechanics of the lumbar spine before and after fusion by determining which physiological motions have the most increase in posterior instrumentation (PI) stresses and FJ loading. Results It was determined that posterior PS fixation increased FJ loading by approximately 35% and 23% at the L3–L4 adjacent level with extension and lateral bending motion, respectively. This increase in FJ loading at the adjacent level could point to the possibility that adjacent segment disease has developed or progressed after posterior lumbar interbody fusion. Furthermore, analyses of peak von Mises stresses on PI showed that the maximum PI stresses of 272.1 MPa and 263.7 MPa occurred in lateral bending and flexion motion before fusion, respectively. Conclusions The effects of a posterior PS fixation system on the biomechanics of the lumbar spine before and after fusion were investigated for all physiological motions. This model could be used as a fundamental tool for further studies, providing a better understanding of the effects of posterior PS fixation by clearing up uncertain aspects.

scholarly journals Análise da Revisão Cochrane: Fixação com Parafusos Pediculares de Fraturas Traumáticas da Coluna Vertebral Torácica e Lombar. Cochrane Database Syst Rev. 2013;05:CD009073.

2016 ◽  
Vol 29 (5) ◽  
pp. 297
Author(s):  
Daniela Vilas Boas Rosa Linhares ◽  
Nuno Neves ◽  
Manuel Ribeiro da Silva ◽  
João Almeida Fonseca
Keyword(s):  
Lumbar Spine ◽  
Bone Graft ◽  
Data Extraction ◽  
Donor Site ◽  
Pedicle Screw Fixation ◽  
Transpedicular Fixation ◽  
Radiological Parameters ◽  
Donor Site Pain ◽  
Thoracic And Lumbar Spine ◽  
Fixation Techniques

<p>Traumatic fractures of the thoracic and lumbar spine are common causes of spine surgery. Pedicle screw fixation is usually chosen, using monosegmentar, short or long segment instrumentations, with or without bone graft. This review aims to evaluate the effect of transpedicular fixation in traumatic fractures of the thoracic and lumbar spine. A systematic search on controlled, randomized or quasi-randomized trials comparing different methods of surgical treatment of this fractures was performed, followed by a process of article selection, data extraction and bias assessment by 3 independent authors. Eight articles were included in a total of 5 comparisons, between different transpedicular fixation techniques. No significant differences on function or quality of life, neurologic status or limitation of motion were found. Only instrumentation with fracture level screw incorporation showed significant decrease of pain when compared with instrumentation alone. Several techniques resulted in significant improvements of different radiological parameters. Significantly, surgeries with smaller duration were associated with lesser blood loss. Bone graft use caused a significant raise in post-operative complications, namely donor site pain. So, this paper showed that significative improvements in radiological parameters do not associate with correspondent clinical benefits, and only instrumentation with level screw incorporation is associated with a clear benefit on pain. Moreover, the need for bone graft is questioned, since it leads to no clinic-radiological improvement with a raise of complications. However, a small number of controlled studies is available on this topic.</p>

scholarly journals Appropriate insertion point for percutaneous pedicle screw placement in the lumbar spine using c-arm fluoroscopy: a cadaveric study

2020 ◽  
Author(s):  
Wei-Xing Xu ◽  
wei-guo Ding ◽  
Bin Xu ◽  
Tian-Hong Hu ◽  
Hong-Feng Sheng ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Pedicle Screw ◽  
Facet Joint ◽  
Outer Edge ◽  
Screw Placement ◽  
Insertion Point ◽  
Pedicle Screw Placement ◽  
X Ray ◽  
Articular Process ◽  
Percutaneous Pedicle Screw

Abstract Background: We studied the characteristics and regularity of appropriate insertion points for percutaneous pedicle screw placement in the lumbar spine using C-arm X-ray fluoroscopy. The purpose of this study was to improve the accuracy of percutaneous pedicle screw placement and reduce the incidence of superior-level facet joint violation. Methods: Six normal spinal specimens were included. Three different methods for placing percutaneous pedicle screws in the lumbar spine were applied, including the Roy-Camille method, Magerl method and Weinstein method. The relationships among the insertion point, pedicle projection and proximal facet joint on C-arm X-ray films were studied. The projection morphology of the vertebral pedicle in different segments of the lumbar spine was observed. The relationship between the outer edge of the pedicle projection and the outer edge of the cranial articular process was also studied. The distance between the insertion point and the facet joint (M1), the distance between the insertion point and outer edge of the cranial articular process (M2), and the distance between the insertion point and the projection center of the pedicle (M) were measured. Results: In this study, we found that the projection shape of the vertebral pedicle differed across segments of the lumbar spine: the shape for L1-L3 was oval, and that for L4-L5 was round. The radiographic study showed that the outer edge of the cranial articular process was located on the lateral side of the outer edge of the pedicle projection and did not overlap with the pedicle projection. M for the Weinstein group was larger than that for the Roy-Camille group (P < 0.05). M1 for the Weinstein group was larger than that for the Roy-Camille and Magerl groups (P < 0.05). M2 for the Roy-Camille group was negative, M2 for the Magerl group was 0, and M2 for the Weinstein group was positive. Conclusion: Under C-arm X-ray fluoroscopy, we were able to accurately identify the characteristics and regularity of the appropriate insertion point for percutaneous pedicle screw placement in the lumbar spine, which was important for improving the accuracy of percutaneous pedicle screw placement and reducing the incidence of superior-level facet joint violation.

scholarly journals Biomechanical Study of Lumbar Spine using Unilateral Pedicle Screw with Tadpole Fixation System

2011 ◽  
Vol 6 (5) ◽  
pp. 391-398 ◽  
Author(s):  
Takamasa YOSHIKAWA ◽  
Suguru OI ◽  
Yuichi KASAI ◽  
Wang ZHUO ◽  
Tadashi INABA ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Pedicle Screw ◽  
Biomechanical Study ◽  
Unilateral Pedicle Screw ◽  
Fixation System

Biomechanical study of the lumbar spine using a unilateral pedicle screw fixation system

2010 ◽  
Vol 17 (3) ◽  
pp. 364-367 ◽  
Author(s):  
Yuichi Kasai ◽  
Tadashi Inaba ◽  
Takaya Kato ◽  
Yoshihiro Matsumura ◽  
Koji Akeda ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Pedicle Screw ◽  
Screw Fixation ◽  
Pedicle Screw Fixation ◽  
Biomechanical Study ◽  
Unilateral Pedicle Screw Fixation ◽  
Unilateral Pedicle Screw ◽  
Fixation System

scholarly journals Appropriate insertion point for percutaneous pedicle screw placement in the lumbar spine using c-arm fluoroscopy: a cadaveric study

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Wei-Xing Xu ◽  
Wei-Guo Ding ◽  
Bin Xu ◽  
Tian-Hong Hu ◽  
Hong-Feng Sheng ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Pedicle Screw ◽  
Facet Joint ◽  
Outer Edge ◽  
Screw Placement ◽  
Insertion Point ◽  
Pedicle Screw Placement ◽  
X Ray ◽  
Articular Process ◽  
Percutaneous Pedicle Screw

Abstract Background We studied the characteristics and regularity of appropriate insertion points for percutaneous pedicle screw placement in the lumbar spine using C-arm X-ray fluoroscopy. The purpose of this study was to improve the accuracy of percutaneous pedicle screw placement and reduce the incidence of superior-level facet joint violation. Methods Six normal spinal specimens were included. Three different methods for placing percutaneous pedicle screws in the lumbar spine were applied, including the Roy-Camille method, Magerl method and Weinstein method. The relationships among the insertion point, pedicle projection and proximal facet joint on C-arm X-ray films were studied. The projection morphology of the vertebral pedicle in different segments of the lumbar spine was observed. The relationship between the outer edge of the pedicle projection and the outer edge of the cranial articular process was also studied. The distance between the insertion point and the facet joint (M1), the distance between the insertion point and outer edge of the cranial articular process (M2), and the distance between the insertion point and the projection center of the pedicle (M) were measured. Results In this study, we found that the projection shape of the vertebral pedicle differed across segments of the lumbar spine: the shape for L1-L3 was oval, and that for L4-L5 was round. The radiographic study showed that the outer edge of the cranial articular process was located on the lateral side of the outer edge of the pedicle projection and did not overlap with the pedicle projection. M for the Weinstein group was larger than that for the Roy-Camille group (P <  0.05). M1 for the Weinstein group was larger than that for the Roy-Camille and Magerl groups (P <  0.05). M2 for the Roy-Camille group was negative, M2 for the Magerl group was 0, and M2 for the Weinstein group was positive. Conclusion Under C-arm X-ray fluoroscopy, we were able to accurately identify the characteristics and regularity of the appropriate insertion point for percutaneous pedicle screw placement in the lumbar spine, which was important for improving the accuracy of percutaneous pedicle screw placement and reducing the incidence of superior-level facet joint violation.

scholarly journals Appropriate insertion point for percutaneous pedicle screw placement in the lumbar spine using c-arm fluoroscopy: a cadaveric study

2020 ◽  
Author(s):  
Wei-Xing Xu ◽  
wei-guo Ding ◽  
Bin Xu ◽  
Tian-Hong Hu ◽  
Hong-Feng Sheng ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Pedicle Screw ◽  
Facet Joint ◽  
Outer Edge ◽  
Screw Placement ◽  
Insertion Point ◽  
Pedicle Screw Placement ◽  
X Ray ◽  
Articular Process ◽  
Percutaneous Pedicle Screw

Abstract Background: We studied the characteristics and regularity of appropriate insertion points for percutaneous pedicle screw placement in the lumbar spine using C-arm X-ray fluoroscopy. The purpose of this study was to improve the accuracy of percutaneous pedicle screw placement and reduce the incidence of superior-level facet joint violation. Methods: Six normal spinal specimens were included. Three different methods for placing percutaneous pedicle screws in the lumbar spine were applied, including the Roy-Camille method, Magerl method and Weinstein method. The relationships among the insertion point, pedicle projection and proximal facet joint on C-arm X-ray films were studied. The projection morphology of the vertebral pedicle in different segments of the lumbar spine was observed. The relationship between the outer edge of the pedicle projection and the outer edge of the cranial articular process was also studied. The distance between the insertion point and the facet joint (M1), the distance between the insertion point and outer edge of the cranial articular process (M2), and the distance between the insertion point and the projection center of the pedicle (M) were measured. Results: In this study, we found that the projection shape of the vertebral pedicle differed across segments of the lumbar spine: the shape for L1-L3 was oval, and that for L4-L5 was round. The radiographic study showed that the outer edge of the cranial articular process was located on the lateral side of the outer edge of the pedicle projection and did not overlap with the pedicle projection. M for the Weinstein group was larger than that for the Roy-Camille group (P < 0.05). M1 for the Weinstein group was larger than that for the Roy-Camille and Magerl groups (P < 0.05). M2 for the Roy-Camille group was negative, M2 for the Magerl group was 0, and M2 for the Weinstein group was positive. Conclusion: Under C-arm X-ray fluoroscopy, we were able to accurately identify the characteristics and regularity of the appropriate insertion point for percutaneous pedicle screw placement in the lumbar spine, which was important for improving the accuracy of percutaneous pedicle screw placement and reducing the incidence of superior-level facet joint violation.

Sign in / Sign up

Export Citation Format

Share Document