Effect of single and multilevel artificial inter-vertebral disc replacement in lumbar spine: A finite element study

2021 ◽  
pp. 039139882110018
Author(s):  
Jayanta Kumar Biswas ◽  
Masud Rana ◽  
Anindya Malas ◽  
Sandipan Roy ◽  
Subhomoy Chatterjee ◽  
...  
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Spinal Fusion ◽  
Disc Replacement ◽  
Disc Disease ◽  
Single Level ◽  
Surgical Methods ◽  
Flexion Extension ◽  
Vertebral Disc ◽  
Spinal Segments

Degenerative disc disease (DDD) in lumbar spine is one of the major musculoskeletal disorders that cause low back pain (LBP). The intervertebral disc structure and dynamics of the lumbar spine are significantly affected by lumbar DDD, leading to a reduced range of motion (ROM), muscle weakness and gradual degradation. Spinal fusion and inter-vertebral disc replacement prostheses are two major surgical methods used for treating lumbar DDD. The aim of this present study is to examine biomechanical impacts of single level (L3-L4 and L4-L5) and multi level (L3-L4-L5) inter-vertebral disc replacement in lumbar spine (L2-L5) and to compare the performance with intact spine. Finite element (FE) analysis has been used to compare the mobility and stress distribution of all the models for four physiological movements, namely flexion, extension, left and right lateral bending under 6, 8 and 10 Nm moments. Spinal fusion implants completely restrict the motion of the implanted segment and increase disc stress at the adjacent levels. In contrast to that, the results single level ADR models showed closer ROM and disc stress to natural model. At the spinal segments adjacent to the implantation, single level ADR shows lower chance of disc degeneration. However, significantly increased ROM was observed in case of double level ADR.

Development of a Strain Transferring Sensor Housing for a Lumbar Spinal Fusion Detection System

2006 ◽  
Vol 1 (2) ◽  
pp. 159-164 ◽  
Author(s):  
J. W. Aebersold ◽  
W. P. Hnat ◽  
M. J. Voor ◽  
R. M. Puno ◽  
D. J. Jackson ◽  
...  
Keyword(s):  
Finite Element ◽  
Spinal Fusion ◽  
Detection System ◽  
Spinal Instrumentation ◽  
Strain Sensor ◽  
Internal Surface ◽  
Disc Disease ◽  
Bending Strain ◽  
Exploratory Surgery

Lumbar arthrodesis or spinal fusion is usually performed to relieve back pain, and regain functionality from degenerative disc disease, trauma, etc. Fusion is determined from radiographic images (X-ray) or computed tomography scans, yet these inspection procedures are subjective methods of review. As a result, exploratory surgery is performed if the presence of fusion cannot be confirmed. Therefore, a need exists to provide objective data to determine the presence of fusion that could avoid the cost, pain, and risk of exploratory surgery. One method to achieve this objective is to observe bending strain from spinal rods implanted during surgery. A system has been developed that will attach to the spinal instrumentation rods, transmit strain information wirelessly, and without the use of batteries. Major components of the system include a strain transferring sensor housing, a microelectromechanical (MEMS)-based strain sensor, telemetry circuitry, and antennae. Only discussed herein are the design, testing, and results of the housing without a cover and its ability to transfer strain from the rod to an internal surface where a foil strain gage is attached to characterize strain transfer efficiency. Strain gauges rather than the MEMS sensor were employed for housing characterization due cost and limited availability. Design constraints for the housing are long-term implantation, small size, greater than 95% transfer of bending strain from the spinal rods to the internal strain sensor, and ease of installation. ABAQUS finite element modeling software was employed to develop a working model that was fabricated using polyetheretherkeytone. The housing underwent cycle testing in a material testing system to simulate long-term implantation along with static testing to determine if creep was present. Both series of tests showed that the housing’s response did not degrade over a period of time and there was no indication of creep. The experimental results also validated the results of the ABAQUS finite element model.

Biomechanical Effect of Lumbar Disc Degeneration Under Flexion/Extension: A Finite Element Model Study

2007 ◽  
Author(s):  
Lissette M. Ruberté ◽  
Raghu Natarajan ◽  
Gunnar B. J. Andersson
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Finite Element Model ◽  
Disc Degeneration ◽  
Pathological Condition ◽  
Lumbar Disc ◽  
Element Model ◽  
Adjacent Segment ◽  
Lumbar Disc Degeneration ◽  
Flexion Extension

Degenerative disc disease (DDD) is a progressive pathological condition observed in 60 to 80% of the population [1]. It involves changes in both the biochemistry and morphology of the intervertebral disc and is associated with chronic low back pain, sciatica and adult scoliosis [2,3]. The most accepted theory of the effects of DDD on the kinematics of the spine is that proposed by Kirkaldy-Willis and Farfan which states that the condition initiates as a temporary dysfunction, followed by instability and then re-stabilization as the disease progresses [4]. Although there is no clear relationship between disc degeneration and the mechanical behavior of the lumbar spine, abnormal motion patterns either in the form of increased motion or erratic motion have been reported from studies on human cadaveric motion segments [5,6]. To date however no study has looked at how disc degeneration affects the adjacent segment mechanics. IN vivo testing is difficult for these purposes given that specimens are generally obtained from people at the later stages of life and consequently often display multiple pathologies. A finite element model is a viable alternative to study the mechanics of the segments adjacent to the diseased disc. It is hypothesized that moderate degeneration at one level will alter the kinematics of the whole lumbar spine.

A Biomechanical Model of Lumbar Spine

2000 ◽  
Author(s):  
Subramanya Uppala ◽  
Robert X. Gao ◽  
Scott Cowan ◽  
K. Francis Lee
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Biomechanical Model ◽  
Element Model ◽  
Fe Model ◽  
Flexion Extension ◽  
Cortical Shell ◽  
Three Dimensional Finite Element

Abstract The strength and stability of the lumbar spine are determined not only by the bone and muscles, but also by the visco-elastic structures and the interplay between the different components of the spine, such as ligaments, capsules, annulus fibrosis, and articular cartilage. In this paper we present a non-linear three-dimensional Finite Element model of the lumbar spine. Specifically, a three-dimensional FE model of the L4-5 one-motion segment/2 vertebrae was developed. The cortical shell and the cancellous bone of the vertebral body were modeled as 3D isoparametric eight-nodal elements. Finite element models of spinal injuries with fixation devices are also developed. The deformations across the different sections of the spine are observed under the application of axial compression, flexion/extension, and lateral bending. The developed FE models provided input to both the fixture design and experimental studies.

A FEM Model Analysis of Human Lumbar Spine With Bi-Level Artificial Disc Replacement

2006 ◽  
Author(s):  
A. Faizan ◽  
A. Kiapour ◽  
V. K. Goel ◽  
A. Ivanov ◽  
A. Biyani ◽  
...  
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Bending Moment ◽  
Element Model ◽  
Good Alternative ◽  
Disc Replacement ◽  
Artificial Disc ◽  
Fem Model ◽  
Artificial Disc Replacement ◽  
Human Lumbar Spine

A finite element model of human lumbar spine (L3-S1 segment) was used to analyze biomechanical effects of the bi-level CHARITE artificial disc replacement (2LCHD) at L4-L5 and L5-S1 levels. The mechanical behavior and range of motion in implanted and intact models were compared using the finite element analyses and a hybrid loading protocol. In 2LCHD model the changes at L3-L4 level decreased by 25% also the model showed smooth changes in motion at implanted levels. In flexion there was an increase in facet loads at lower levels of 2LCHD however the bending moment in this model was less than intact model because of hybrid loading; in contrast, the facet loads in implanted model decreased in extension. It was observed that the bi-level disc replacement won’t affect much the kinematics of the spine and can be proposed as a good alternative for treatment in cases that disc degeneration occurs at more than one level of spine.

Design and development of a novel expanding flexible rod device (FRD) for stability in the lumbar spine: A finite-element study

2020 ◽  
Vol 43 (12) ◽  
pp. 803-810 ◽  
Author(s):  
Masud Rana ◽  
Sandipan Roy ◽  
Palash Biswas ◽  
Shishir Kumar Biswas ◽  
Jayanta Kumar Biswas
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Range Of Motion ◽  
Pedicle Screw ◽  
Axial Rotation ◽  
Von Mises Stress ◽  
Lateral Bending ◽  
Intact Bone ◽  
Flexion Extension ◽  
Von Mises

The aim of this study is to design a novel expanding flexible rod device, for pedicle screw fixation to provide dynamic stability, based on strength and flexibility. Three-dimensional finite-element models of lumbar spine (L1-S) with flexible rod device on L3-L4-L5 levels are developed. The implant material is taken to be Ti-6Al-4V. The models are simulated under different boundary conditions, and the results are compared with intact model. In natural model, total range of motion under 10 Nm moment were found 66.7°, 24.3° and 13.59°, respectively during flexion–extension, lateral bending and axial rotation. The von Mises stress at intact bone was 4 ± 2 MPa and at bone, adjacent to the screw in the implanted bone, was 6 ± 3 MPa. The von Mises stress of disc of intact bone varied from 0.36 to 2.13 MPa while that of the disc between the fixed vertebra of the fixation model reduced by approximately 10% for flexion and 25% for extension compared to intact model. The von Mises stresses of pedicle screw were 120, 135, 110 and 90 MPa during flexion, extension, lateral bending, and axial rotation, respectively. All the stress values were within the safe limit of the material. Using the flexible rod device, flexibility was significantly increased in flexion/extension but not in axial rotation and lateral bending. The results suggest that dynamic stabilization system with respect to fusion is more effective for homogenizing the range of motion of the spine.

Vertebral body split fracture after a single-level cervical total disc replacement

2012 ◽  
Vol 16 (3) ◽  
pp. 231-235 ◽  
Author(s):  
Tsung-Hsi Tu ◽  
Jau-Ching Wu ◽  
Li-Yu Fay ◽  
Chin-Chu Ko ◽  
Wen-Cheng Huang ◽  
...  
Keyword(s):  
Surgical Treatment ◽  
Total Disc Replacement ◽  
Radicular Pain ◽  
Disc Replacement ◽  
Viable Option ◽  
Disc Disease ◽  
Cervical Total Disc Replacement ◽  
Single Level ◽  
Linear Fracture

Cervical total disc replacement (TDR) is a viable option for the surgical treatment of degenerative disc disease. This 67-year-old nonsmoking male patient underwent single-level ProDisc-C cervical TDR at C5–6 without any intraoperative problem. His radicular pain improved and he had no neck pain immediately after the operation. However, on postoperative Day 3, a radiograph demonstrated a vertical split fracture of the C-5 vertebra. This fracture was managed conservatively, and 2 years postoperatively a follow-up CT scan demonstrated stable device position and fusion of the fracture. Although the linear fracture caused no neurological symptoms or device migration, the authors advocate prudence in selection and installation of keel-design prostheses, even in a single-level cervical TDR scenario.

scholarly journals Biomechanical Evaluation of Cortical Bone Trajectory Fixation with Traditional Pedicle Screw in the Lumbar Spine: A Finite Element Study

2021 ◽  
Vol 11 (22) ◽  
pp. 10583
Author(s):  
Kuo-Chih Su ◽  
Kun-Hui Chen ◽  
Chien-Chou Pan ◽  
Cheng-Hung Lee
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Cortical Bone ◽  
Pedicle Screw ◽  
Spinal Surgery ◽  
Pedicle Screws ◽  
Element Model ◽  
Cortical Bone Trajectory ◽  
Significant Difference ◽  
Flexion Extension

Cortical bone trajectory (CBT) is increasingly used in spinal surgery. Although there are many biomechanical studies, the biomechanical effect of CBT in combination with traditional pedicle screws is not detailed. Therefore, the purpose of this study was to investigate the effects of the traditional pedicle screw and CBT screw implantation on the lumbar spine using finite element methods. Based on the combination of the traditional pedicle screw and the CBT system implanted into the lumbar spine, four finite element spinal lumbar models were established. The models were given four different load conditions (flexion, extension, lateral bending, and axial rotation), and the deformation and stress distribution on the finite element model were observed. The results show that there was no significant difference in the structural stability of the lumbar spine model between the traditional pedicle screw system and the CBT system. In addition, CBT may reduce stress on the endplate. Different movements performed by the model may have significant biomechanical effects on the spine and screw system. Clinical spinal surgeons may also consider using the CBT system in revision spinal surgery, which may contribute to smaller wounds.

Stress Analysis of the Lower Lumbar Spine Three-joint Complex According to Different Pelvic Incidences

2021 ◽  
Author(s):  
Qi Lai ◽  
Jun Yin ◽  
Zi Zhen Zhang ◽  
Jie Yang ◽  
Zongmiao Wan
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Pelvic Incidence ◽  
Facet Joint ◽  
The Other ◽  
Von Mises Stress ◽  
Facet Joints ◽  
Lower Lumbar Spine ◽  
Flexion Extension ◽  
Lower Lumbar

Abstract Background: Pelvic incidence is closely related to degeneration of the facet joint and intervertebral disc and is related to the orientation of the facet joints. Currently, very few studies have been conducted on the force analysis of the three-joint complex in patients with different pelvic incidence measurements under different sports postures. We designed this study to better assess the influence of pelvic incidence on the stress of the lumbar three-joint complex. Finite element analysis can provide a biomechanical basis for the relationship between different pelvic incidences and degenerative diseases of the lower lumbar spine.Methods: We developed three nonlinear finite element models of the lumbar spine (L1-S1) with different pelvic incidences (27.44°, 47.05°, and 62.28°) and validated them to study the biomechanical response of facet joints and intervertebral discs with a follower preload of 400 N, under different torques (5 Nm, 10 Nm, and 15 Nm), and compared the stress of the three-joint complex of the lower lumbar spine (L3-S1) in different positions (flexion-extension, left-right bending, and left-right torsion).Results: In the flexion position, the stress of the disc in the low pelvic incidence model was the largest among the three models; the stress of the facet joint in the high pelvic incidence model was the largest among the three groups during the extension position. During torsion, the intradiscal pressure of the high pelvic incidence model was higher than that of the other two models in the L3/4 segment, and the maximum von Mises stress of the annulus fibrosus in the L5/S1 segment with a large pelvic incidence was greater than that of the other two models.Conclusions: Pelvic incidence is related to the occurrence and development of degenerative lumbar diseases. The stress of the lower lumbar facet joints and fibrous annulus of individuals with a high pelvic incidence is greater than that of individuals with a low pelvic incidence or a normal pelvic incidence. Although this condition only occurs in individual segments, to a certain extent, it can also reflect the influence of pelvic incidence on the force of the three-joint complex of the lower lumbar spine.

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