Effect of screw thread length on stiffness of proximal humerus locking plate constructs: A finite element study

2019 ◽  
Vol 63 ◽  
pp. 79-87 ◽  
Author(s):  
Louise Le ◽  
Ali Jabran ◽  
Chris Peach ◽  
Lei Ren
Keyword(s):  
Finite Element ◽  
Locking Plate ◽  
Proximal Humerus ◽  
Screw Thread ◽  
Finite Element Study ◽  
Thread Length ◽  
Element Study

scholarly journals Effects of the Insertion Type and Depth on the Pedicle Screw Pullout Strength: A Finite Element Study

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
K. Jendoubi ◽  
Y. Khadri ◽  
M. Bendjaballah ◽  
N. Slimane
Keyword(s):  
Finite Element ◽  
Pedicle Screw ◽  
Pedicle Screws ◽  
Osteoporotic Bone ◽  
Screw Thread ◽  
Pullout Strength ◽  
Pullout Resistance ◽  
Finite Element Study ◽  
Screw Breakage ◽  
Element Study

Purpose. The pedicle screw is a surgical device that has become widely used in spinal fixation and stabilization. Postsurgical complications such as screw loosening due to fatigue loading and screw breakage still need investigations. Clinical parameters such as the screw insertion type and depth, the bone density, and the patient degree of mobility greatly affect the mechanisms of the implant’s failure/success. Methods. The current finite element study focused on the prediction of the pedicle screw pullout strength under various conditions such as insertion type, insertion depth, bone quality, and loading mode. Results. As depicted in this study, the preservation of the pedicle cortex as in the N1 insertion technique greatly enhances the pullout resistance. In addition, the higher the screw-anchoring depth, permitting to gear a maximum number of threads, the better the protection against premature breakouts of pedicle screws. Conclusions. In agreement with experimental data, the type of insertion in which the first screw thread is placed immediately after the preserved pedicle cortex showed the best pullout resistance for both normal and osteoporotic bone.

Finite-Element Study of Biomechanical Explanations for Bone Loss around Dental Implants

2020 ◽  
Vol 30 (1) ◽  
pp. 21-30
Author(s):  
Ali Merdji ◽  
Belaid Taharou ◽  
Rajshree Hillstrom ◽  
Ali Benaissa ◽  
Sandipan Roy ◽  
...  
Keyword(s):  
Finite Element ◽  
Bone Loss ◽  
Dental Implants ◽  
Finite Element Study ◽  
Element Study

scholarly journals Finite Element Study on Calculation of Nonlinear Soil Consolidation Using Compression and Recompression Indexes

2020 ◽  
Vol 10 (14) ◽  
pp. 4737
Author(s):  
Chao Xu ◽  
Suli Pan
Keyword(s):  
Finite Element ◽  
Case History ◽  
Time Dependent ◽  
Discrete Equation ◽  
Soil Consolidation ◽  
Coefficient Of Consolidation ◽  
Finite Element Study ◽  
Nonlinear Consolidation ◽  
Element Study

The coefficient of consolidation is traditionally considered as a constant value in soil consolidation calculations. This paper uses compression and recompression indexes to calculate the solution-dependent nonlinear compressibility, thus overconsolidation and normal consolidation are separated during the calculations. Moreover, the complex nonlinear consolidation can be described using the nonlinear compressibility and a nonlinear permeability. Then, the finite element discrete equation with consideration of the time-dependent load is derived, and a corresponding program is developed. Subsequently, a case history is conducted for verifying the proposed method and the program. The results show that the method is sufficiently accurate, indicating the necessity of considering nonlinearity for consolidation calculations. Finally, three cases are compared to reveal the importance of separating the overconsolidation and normal consolidation. Overall, this study concluded that it is inadequate to consider just one consolidation status in calculations, and that the proposed method is more reasonable for guiding construction.

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