Effects of extraosseous talotarsal stabilization on the biomechanics of flexible flatfoot subtalar joints in children: a finite element study

Background: Objective of the study was to generate an experimental foundation for the clinical application of extraosseous talotarsal stabilization (EOTTS) in treatment of flexible flatfeet in children by investigating the biomechanical characteristics of flexible flatfoot and the effects of EOTTS on hindfoot biomechanics.Methods: Three-dimensional finite element models of the foot and ankle complex were generated from computer tomography images of a volunteer’s left foot in three states: normal, flexible flatfoot, and post-EOTTS. After validation by X-ray, simulated loads were applied to the three models in a neutral position with both feet standing.Results: In the flexible flatfoot model, the contact stress on the subtalar joint increased and contact areas decreased, resulting in abnormal stress distribution compared to the normal model. However, following treatment of the foot with EOTTS, these parameters returned to close to normal. Subtalar joint instability leads to a flexible flat foot. Based on this study, it is proposed that EOTTS can restore the normal function of the subtalar joint in and is an effective treatment for flexible flatfoot in children. We and many clinical data studies provide evidence for sinus tarsi implants in pediatric patients. It is showed that the formation of flexible flatfoot is induced by subtalar joint instability.Conclusions: Because of the EOTTS provides the best biomechanical solution to subtalar joint instability, the EOTTS became an effective form for subtalar joint instability treatment.

Download Full-text

Finite element analysis of wedge and biconcave deformity in four different height restoration after augmentation of osteoporotic vertebral compression fracture

10.21203/rs.3.rs-38291/v1 ◽

2020 ◽

Author(s):

Xiao-Hua Zuo ◽

Ying-Bing Chen ◽

Peng Xie ◽

Wen-Dong Zhang ◽

Xiang-Yun Xue ◽

...

Keyword(s):

Finite Element ◽

Three Dimensional ◽

Axial Rotation ◽

Neutral Position ◽

Element Analysis ◽

Flexion Extension ◽

Dimensional Finite Element ◽

Von Mises ◽

Three Dimensional Finite Element ◽

Wedge Fracture

Abstract Purpose Biomechanical comparison of wedge and biconcave deformity of different height restoration after augmentation of osteoporotic vertebral compression fractures was analyzed by three-dimensional finite element analysis (FEA). Methods Three-dimensional finite element model (FEM) of T11-L2 segment was constructed from CT scan of elderly osteoporosis patient. The von Mises stresses of vertebrae, intervertebral disc, facet joints, displacement, and range of motion (ROM) of wedge and biconcave deformity were compared at four different heights (Genant 0–3 grade) after T12 vertebral augmentation. Results In wedge deformity, the stress of T12 decreased as the vertebral height in neutral position, flexion, extension and left axial rotation, whereas increased sharply in bending at Genant 0; L1 and L2 decreased in all positions excluding flexion of L2, and T11 increased in neutral position, flexion, extension, and right axial rotation at Genant 0. No significant changes in biconcave deformity. The stress of T11-T12, T12-L1, and L1-L2 intervertebral disc gradually increased or decreased under other positions in wedge fracture, whereas L1-L2 no significant change in biconcave fracture. The utmost overall facet joint stress is at Genant 3, whereas there is no significant change under the same position in biconcave fracture. The displacement and ROM of the wedge fracture had ups and downs, while a decline in all positions excluding extension in biconcave fracture. Conclusions The vertebral restoration height after augmentation to Genant 0 affects the von Mises stress, displacement, and ROM in wedge deformity, which may increase the risk of fracture; Whereas restored or not in biconcave deformity.

Download Full-text

Finite element analysis of wedge and biconcave deformity in four different height restoration after augmentation of osteoporotic vertebral compression fractures

Journal of Orthopaedic Surgery and Research ◽

10.1186/s13018-021-02225-8 ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

Xiao-Hua Zuo ◽

Yin-Bing Chen ◽

Peng Xie ◽

Wen-Dong Zhang ◽

Xiang-Yun Xue ◽

...

Keyword(s):

Finite Element ◽

Three Dimensional ◽

Axial Rotation ◽

Vertebral Compression Fractures ◽

Neutral Position ◽

Element Analysis ◽

Flexion Extension ◽

Dimensional Finite Element ◽

Von Mises ◽

Three Dimensional Finite Element

Abstract Purpose Biomechanical comparison of wedge and biconcave deformity of different height restoration after augmentation of osteoporotic vertebral compression fractures was analyzed by three-dimensional finite element analysis (FEA). Methods Three-dimensional finite element model (FEM) of T11-L2 segment was constructed from CT scan of elderly osteoporosis patient. The von Mises stresses of vertebrae, intervertebral disc, facet joints, displacement, and range of motion (ROM) of wedge and biconcave deformity were compared at four different heights (Genant 0–3 grade) after T12 vertebral augmentation. Results In wedge deformity, the stress of T12 decreased as the vertebral height in neutral position, flexion, extension, and left axial rotation, whereas increased sharply in bending at Genant 0; L1 and L2 decreased in all positions excluding flexion of L2, and T11 increased in neutral position, flexion, extension, and right axial rotation at Genant 0. No significant changes in biconcave deformity. The stress of T11-T12, T12-L1, and L1-L2 intervertebral disc gradually increased or decreased under other positions in wedge fracture, whereas L1-L2 no significant change in biconcave fracture. The utmost overall facet joint stress is at Genant 3, whereas there is no significant change under the same position in biconcave fracture. The displacement and ROM of the wedge fracture had ups and downs, while a decline in all positions excluding extension in biconcave fracture. Conclusions The vertebral restoration height after augmentation to Genant 0 affects the von Mises stress, displacement, and ROM in wedge deformity, which may increase the risk of fracture, whereas restored or not in biconcave deformity.

Download Full-text

Finite element analysis of wedge and biconcave deformity in four different height restoration after augmentation of osteoporotic vertebral compression fracture

10.21203/rs.3.rs-38291/v2 ◽

2020 ◽

Author(s):

Xiao-Hua Zuo ◽

Ying-Bing Chen ◽

Peng Xie ◽

Wen-Dong Zhang ◽

Xiang-Yun Xue ◽

...

Keyword(s):

Finite Element ◽

Three Dimensional ◽

Axial Rotation ◽

Neutral Position ◽

Element Analysis ◽

Flexion Extension ◽

Dimensional Finite Element ◽

Von Mises ◽

Three Dimensional Finite Element ◽

Wedge Fracture

Abstract Purpose : Biomechanical comparison of wedge and biconcave deformity of different height restoration after augmentation of osteoporotic vertebral compression fractures was analyzed by three-dimensional finite element analysis (FEA). Methods: Three-dimensional finite element model (FEM) of T11-L2 segment was constructed from CT scan of elderly osteoporosis patient. The von Mises stresses of vertebrae, intervertebral disc, facet joints, displacement, and range of motion (ROM) of wedge and biconcave deformity were compared at four different heights (Genant 0-3 grade) after T12 vertebral augmentation. Results: In wedge deformity, the stress of T12 decreased as the vertebral height in neutral position, flexion, extension and left axial rotation, whereas increased sharply in bending at Genant 0; L1 and L2 decreased in all positions excluding flexion of L2, and T11 increased in neutral position, flexion, extension, and right axial rotation at Genant 0. No significant changes in biconcave deformity. The stress of T11-T12, T12-L1, and L1-L2 intervertebral disc gradually increased or decreased under other positions in wedge fracture, whereas L1-L2 no significant change in biconcave fracture. The utmost overall facet joint stress is at Genant 3, whereas there is no significant change under the same position in biconcave fracture. The displacement and ROM of the wedge fracture had ups and downs, while a decline in all positions excluding extension in biconcave fracture.Conclusionons : The vertebral restoration height after augmentation to Genant 0 affects the von Mises stress, displacement, and ROM in wedge deformity, which may increase the risk of fracture; Whereas restored or not in biconcave deformity.

Download Full-text

Finite Element Analysis of Nonuniformity of Tires with Imperfections5

Tire Science and Technology ◽

10.2346/1.2768607 ◽

2007 ◽

Vol 35 (3) ◽

pp. 226-238 ◽

Cited By ~ 1

Author(s):

K. M. Jeong ◽

K. W. Kim ◽

H. G. Beom ◽

J. U. Park

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Three Dimensional ◽

Element Model ◽

Radial Force ◽

Element Analysis ◽

The Finite Element Analysis ◽

Dimensional Finite Element ◽

Force Variation ◽

Three Dimensional Finite Element

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.

Download Full-text