The CENTERPIECE™ Posterior Cervical Laminoplasty and Internal Fixation System

Objectives. The optimization for the screw configurations and bone plate parameters was studied to improve the biomechanical performances such as reliable internal fixation and beneficial callus growth for the clinical treatment of femoral shaft fracture. Methods. The finite element analysis (FEA) of internal fixation system under different screw configurations based on the orthogonal design was performed and so was for the different structural parameters of the locking plate based on the combination of uniform and orthogonal design. Moreover, orthogonal experiment weight matrixes for four evaluation indexes with FEA were analyzed. Results. The analytical results showed the optimal scheme of screw configuration was that screws are omitted in the thread holes near the fracture site, and single cortical screws are used in the following holes to the distal end, while the double cortical screws are fixed in thread holes that are distal to the fracture; in the other words, the length of the screws showed an increasing trend from the fracture site to the distal end in the optimized configuration. The plate structure was optimized when thread holes gap reached 13 mm, with a width of 11 mm and 4.6 mm and 5 mm for thickness and diameter of the screw, respectively. The biomechanical performance of the internal fixation construct was further improved by about 10% based on the optimal strain range and lower stress in the internal fixation system. Conclusions. The proposed orthogonal design and uniform design can be used in a more efficient way for the optimization of internal fixation system, which can reduce the simulation runs to about 10% compared with comprehensive test, and the methodology can be also used for other types of fractures to achieve better internal fixation stability and optimal healing efficiency, which may provide a method for an orthopedist in choosing the screw configurations and parameters for internal fixation system in a more efficient way.

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Post Healing Structural Response of an Internal Fixation System for a Mid-Shaft Radius Fracture

Volume 2: Biomedical and Biotechnology Engineering ◽

10.1115/imece2007-41600 ◽

2007 ◽

Author(s):

Cameron Coates ◽

Camille Coates-Clark ◽

Mykal Woody

Keyword(s):

Internal Fixation ◽

Mechanical Response ◽

Structural Response ◽

Shaft Fracture ◽

Bone Plate ◽

Healthy Adult Male ◽

System Selection ◽

Plate System ◽

Internal Fixation System ◽

Fixation System

Inexpensive models of the radius with and without an internal fixation system for a mid-shaft fracture are developed and analyzed using the Finite Element Method (FEM). FE models are based on geometry obtained from simple yet effective manufacturing methods. Median trabecular and cortical bone mechanical properties for a healthy adult male are used in the FEM model. These models are used to quantify the changes in bone stresses that occur when internal fixation devices are retained after the fracture has healed. The linear static responses to tensile and torsional loads with and without bone plates are examined. The static response trends obtained agree reasonably well with current literature where more expensive modeling techniques were used. A fatigue analysis is also performed based on the FE static results coupled with S-N curves for the plate and bone material in order to predict the combined mechanical response of the bone plate system over time. Recommendations are suggested which may be used as additional guidelines to consider for bone plate system selection and determination of hardware removal.

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Three-dimensional finite element analysis of a newly developed aliform internal fixation system for occipitocervical fusion

Medical Engineering & Physics ◽

10.1016/j.medengphy.2016.08.011 ◽

2016 ◽

Vol 38 (12) ◽

pp. 1392-1398

Author(s):

Sui-Xiang Liao ◽

Jian-Hua Wang ◽

Yong-Qiang Zheng ◽

Guan Zheng ◽

Ge-Jing Wei ◽

...

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Internal Fixation ◽

Three Dimensional ◽

Occipitocervical Fusion ◽

Element Analysis ◽

Dimensional Finite Element ◽

Three Dimensional Finite Element ◽

Internal Fixation System ◽

Fixation System

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Management of a nonunion of the distal femur in osteoporotic bone with the internal fixation system LISS (less invasive stabilization system)

Archives of Orthopaedic and Trauma Surgery ◽

10.1007/s00402-006-0102-0 ◽

2006 ◽

Vol 126 (5) ◽

pp. 350-353 ◽

Cited By ~ 17

Author(s):

Yasmin D. Hailer ◽

Reinhard Hoffmann

Keyword(s):

Internal Fixation ◽

Distal Femur ◽

Osteoporotic Bone ◽

Stabilization System ◽

Less Invasive ◽

Less Invasive Stabilization System ◽

Internal Fixation System ◽

Fixation System

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Structural Assessment of an Internal Fixation System for a Forearm Long Bone Mid-shaft Fracture

Journal of Undergraduate Materials Research ◽

10.21061/jumr.v3i0.0801 ◽

2008 ◽

Vol 3 (0) ◽

Author(s):

MyKal Woody

Keyword(s):

Internal Fixation ◽

Shaft Fracture ◽

Long Bone ◽

Structural Assessment ◽

Internal Fixation System ◽

Fixation System

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Finite Element Analysis and Comparative Study of 4 Kinds of Internal Fixation Systems for Anterior Cervical Discectomy and Fusion in Children

10.21203/rs.3.rs-1025811/v1 ◽

2021 ◽

Author(s):

ziyu li ◽

Jianqiang Zhou ◽

Zhijun Li ◽

Shaojie Zhang ◽

xing wang ◽

...

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Cervical Spine ◽

Finite Element Model ◽

Internal Fixation ◽

Element Model ◽

Lower Cervical Spine ◽

Element Analysis ◽

Internal Fixation System ◽

Fixation System

Abstract Background: Spinal injury in children usually occurs in the cervical spine region. Anterior fixation of lower cervical spine has been applied in the treatment of pediatric cervical spine injury and disease due to its stable and firm mechanical properties. This study performed finite element analysis and comparison of 4 different anterior cervical internal fixation systems for children, and explored more stable methods of anterior cervical internal fixation in children. Methods: A finite element model of 6-year-old children with lower cervical spine C4/5 discectomy was established, and the self-designed lower cervical spine anterior locking internal fixation system ACBLP and the children’s anterior cervical internal fixation system ACOP, ACVLP, ACSLP plate screws were fixed and loaded on the model. 27.42N•m torque load was applied to each internal fixation model under 6 working conditions of anteflexion, backward flexion, left flexion, right flexion, left rotation and right rotation, to simulate the movement of the cervical spine. The activity and stress distribution cloud diagram of each finite element model was obtained. Results: In the four internal fixation models of ACOP, ACVLP, ACSLP, and ACBLP, the mobility of C4/5 segment basically showed a decreasing relationship, and the mobility of adjacent segments increased significantly. In the Mises stress cloud diagram of the cervical spine of the four models, the vertebral body and accessories of the ACBLP model born the least stress, followed by ACSLP; The steel plate and screws in the ACVLP internal fixation model were the most stressed; The stress of the internal fixation system (plate/screw) in all models increased in the order of ACBLP, ACSLP, ACVLP, and ACOP.Conclusions: ACBLP internal fixation system had obvious advantages in anterior internal fixation of lower cervical spine in children, C4/5 had the smallest degree of movement, relative displacement was minimal, the stress on the pedicle was the least while the stress on the plate screw was relatively the smallest.

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