scholarly journals Comparative Analysis for Internal Fixations of Pauwels II by Biomechanical Finite Element Method

2019 ◽  
Vol 103 (9-10) ◽  
pp. 493-504
Author(s):  
Matthew Jian-Qiao Peng ◽  
Xiangyang Ju ◽  
Hai-Yan Chen ◽  
Bai Bo ◽  
XinXu Li
Keyword(s):  
Finite Element ◽  
South Carolina ◽  
Femoral Neck ◽  
Femoral Neck Fracture ◽  
3D Models ◽  
Secondary Fracture ◽  
Solid Models ◽  
Neck Fracture ◽  
Hip Screw ◽  
3D Solid

Purpose: A series models of surgical internal fixation for femoral neck fracture of Pauwels II will be constructed by an innovative approach of finite element so as to determine the most stable fixation by comparison of their biomechanical performance. Method: Seventeen specimens of proximal femurs scanned by computed tomography in Digital Imaging and Communications in Medicine (DICOM) format were input onto Mimics rebuilding 3D models; their stereolithography (STL) format dataset were imported into Geomagic Studio (3D Systems, Rock Hill, South Carolina) for simulative osteotomy and non-uniform rational basis spline kartograph; the generated IGS dataset were interacted by UG to fit simulative 3D-solid models; 3 sorts of internal fixators were expressed in 3D model by ProE (PTC, Boston, Connecticut) program virtually. Processed by HyperMesh (Altair, Troy, Michigan), all compartments (fracture model + internal immobilization) were assembled onto 3 systems actually as: Dynamic hip screw (DHS) / Lag screw (LS) / DHS+LS. Eventually, a numerical model of finite elemental analysis was exported to ANSYS for solution. Result: Three models of internal fixations for femoral neck fracture of Pauwels II were established and validated effectively, the stress and displacement of each internal pin were analyzed, the advantages of each surgical therapy for femoral neck fracture of Pauwels II were compared and demonstrated synthetically as: “The contact stress of 3-LS-system was checked to be the least; the interfragmentary displacement of DHS+1-LS assemblages was assessed to be the least.” Conclusion: 3-LS-system is recommended to be a clinical optimization for Pauwels II femoral neck facture, by this therapeutic fixation mechanically, breakage of fixators, or secondary fracture rarely occurs.

COMPARATIVE ANALYSIS FOR THREE FIXTURES OF PAUWELLS-II BY THE BIOMECHANICAL FINITE ELEMENT METHOD

2019 ◽  
Vol 20 (01) ◽  
pp. 1950079
Author(s):  
MATTHEW JIAN-QIAO PENG ◽  
HONGWEN XU ◽  
HAI-YAN CHEN ◽  
XIANGYANG JU ◽  
YONG HU ◽  
...  
Keyword(s):  
Finite Element ◽  
Numerical Models ◽  
Femoral Shaft ◽  
3D Models ◽  
Procedure Time ◽  
Stable Fixation ◽  
Secondary Fracture ◽  
Solid Models ◽  
Acute Correction ◽  
Hip Screw

Little is known about why and how biomechanics govern the hypothesis that three-Lag-Screw (3LS) fixation is a preferred therapeutic technique. A series models of surgical internal-fixation for femoral neck fractures of Pauwells-II will be constructed by an innovative approach of finite element so as to determine the most stable fixation by comparison of their biomechanical performance. Seventeen sets of CT scanned femora were imported onto Mimics extracting 3D models; these specimens were transferred to Geomagic Studio for a simulative osteotomy and kyrtograph; then, they underwent UG to fit simulative solid models; three sorts of internal fixators were expressed virtually by Pro-Engineer. Processed by Hypermesh, all compartments were assembled onto three systems actually as “Dynamic hip screw (DHS), 3LS and DHS+LS”. Eventually, numerical models of Finite Elemental Analysis (FEA) were exported to AnSys for solution. Three models for fixtures of Pauwells-II were established, validated and analyzed with the following findings: Femoral-shaft stress for [Formula: see text](3LS) is the least; Internal-fixator stress (MPa) for [Formula: see text]; Integral stress (MPa) for [Formula: see text]; displacement of femoral head (mm) for a[Formula: see text](DHS+LS) = 0.735; displacement of femoral shaft (mm) for [Formula: see text]; and displacement of fixators for [Formula: see text]. Mechanical comparisons for other femoral parks are insignificantly different, and these data can be abstracted as follows: the stress of 3LS-system was checked to be the least, and an interfragmentary displacement of DHS+LS assemblages was assessed to be the least”. A 3LS-system should be recommended to clinically optimize a Pauwells-II facture; if treated by this therapeutic fixation, breakage of fixators or secondary fracture is supposed to occur rarely. The strength of this study is that it was performed by a computer-aided simulation, allowing for design of a preoperative strategy that could provide acute correction and decrease procedure time, without harming to humans or animals.

Modified F Configuration in the Treatment of Pauwels Type III Femoral Neck Fracture: a Finite Element Analysis

2021 ◽  
Author(s):  
Shiyuan Lin ◽  
Huizi Li ◽  
Kai Tong ◽  
Zihang Feng ◽  
Gang Wang ◽  
...  
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Femoral Neck ◽  
Femoral Neck Fracture ◽  
Femoral Neck Fractures ◽  
Cannulated Screw ◽  
Type Iii ◽  
Neck Fracture ◽  
Maximum Crack ◽  
Hip Screw

Abstract Background: The optimal treatment of Pauwels type III femoral neck fracture in young patients remains a worldwide challenge in orthopedic surgery. Methods: Finite element models of four internal fixations were developed to treat Pauwels type III Femoral neck fracture: a: the traditional inverted triangular cannulated screw model, b: the F-technique cannulated screw model, c: the modified F-technique cannulated screw model using a fully threaded screw instead of a partially threaded distally, d: the dynamic hip screw coupled with anti-rotational screw model. Under the same conditions, finite element analyses were carried out to compare the displacement and von Mises stress distribution of four internal fixations and femurs, the maximum crack distances of the fracture surfaces, Z axis displacements of four models as well as the stress distribution in the subtrochanteric region. Results: The modified F-technique configuration resulted in a more stable fixation as compared to the other three approaches, with respect to the maximum displacement and stress peaks of femur and internal fixations, the maximum crack distances of the fracture surfaces, Z axis displacements of four configurations as well as the stress distribution in the subtrochanteric region.Conclusions: Our results suggested that modified F-technique configuration show a better performance in resisting shearing and rotational forces in treating Pauwels type III femoral neck fractures compared to those using traditional inverted triangular, the F-technique configuration or dynamic hip screw coupled with anti-rotational screw, providing a new choice for the treatment of femoral neck fractures.

scholarly journals Treatment of the Femoral Neck Fracture Using a Compression Hip Screw

1980 ◽  
Vol 29 (1) ◽  
pp. 1-4
Author(s):  
K. Ohno ◽  
J. Tokunaga ◽  
H. Ueno ◽  
A. Kobayashi ◽  
K. Fukumoto ◽  
...  
Keyword(s):  
Femoral Neck ◽  
Femoral Neck Fracture ◽  
Neck Fracture ◽  
Hip Screw

scholarly journals Clinical Observation and Finite Element Analysis of Cannulated Screw Internal Fixation in the Treatment of Femoral Neck Fracture Based on Different Reduction Quality

2021 ◽  
Author(s):  
Gan Zhao ◽  
Ming Liu ◽  
bin Li ◽  
haizhong Sun ◽  
Biaofang Wei
Keyword(s):  
Finite Element ◽  
Femoral Neck ◽  
Internal Fixation ◽  
Femoral Neck Fracture ◽  
Cannulated Screw ◽  
Anatomical Reduction ◽  
Significant Difference ◽  
Reduction Group ◽  
Neck Fracture ◽  
Time From Injury

Abstract Objective: Femoral neck fracture is one of the most common bone types. The effect of reduction quality on hip joint function and complications after screw internal fixation is not fully understood. To investigate the clinical efficacy and mechanical mechanism of positive buttress, anatomical reduction and negative buttress in the treatment of femoral neck fracture after cannulated screw fixation.Methods: Retrospective analysis of patients with femoral neck fracture treated with three cannulated screws internal fixation in our hospital from January 2013 to December 2018.According to the quality of fracture reduction, the patients were divided into positive buttress group, anatomical reduction group and negative buttress group. Basic information such as injury mechanism, time from injury to surgery, Garden classification and Pauwels classification was collected, Harris scores were performed at 3 months, 6 months and 12 months after surgery, and postoperative complications (femoral head necrosis, femoral neck shortening and femoral neck nonunion) were collected. At the same time, three groups of finite element models with different reduction quality were established for stress analysis, their stress clouds were observed and the average displacement and stress of the three groups of models were compared. P < 0.05 was used to represent a statistically significant difference.Results: A total of 225 cases of unilateral femoral neck fractures were included and followed up for an average of 4.12 ± 0.69 years. There was no significant difference in age, gender, side, injury mechanism, time from injury to surgery, BMI, Garden classification, Pauwels classification and follow-up time among the three groups (P > 0.05).However, there was significant difference in harris score at 6 and 12 months after operation among the three groups (P < 0.05), which was higher in the positive buttress group and anatomical reduction group than in the negative buttress group. In addition, the incidence of osteonecrosis of the femoral head in the negative buttress group (32.2%) was greater than that in the anatomical reduction group (13.4%) and the positive buttress group (5.4%) (P < 0.05). In addition, the incidence of femoral neck nonunion and femoral neck shortening in the negative buttress group was also higher than that in the anatomical reduction positive buttress group (P < 0.05). The finite element results showed that the stress and fracture end displacement in the negative buttress group were greater than those in the positive buttress group (P < 0.05).Conclusion: Both positive buttress and anatomical reduction in the treatment of femoral neck fracture with cannulated screw internal fixation can obtain better clinical effect and lower postoperative complications. Positive brace support and anatomic reduction can limit the restoration of femoral stress conduction. Therefore, it is not necessary to pursue anatomical reduction too deliberately during surgery, while negative buttress reduction should be avoided.

scholarly journals Finite Element Analysis of Femoral Neck Fracture Treated with Bidirectional Compression-Limited Sliding Screw

2021 ◽  
Vol 27 ◽  
Author(s):  
Hai Huang ◽  
Zhengkuan Feng ◽  
Weifei Wang ◽  
Cheng Yang ◽  
Jianwen Liao ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Femoral Neck ◽  
Femoral Neck Fracture ◽  
Element Analysis ◽  
Neck Fracture

scholarly journals Medial anatomical buttress plate in treating displaced femoral neck fracture a finite element analysis

Injury ◽  
2019 ◽  
Vol 50 (11) ◽  
pp. 1895-1900
Author(s):  
Jia Li ◽  
Pengbin Yin ◽  
Licheng Zhang ◽  
Hua Chen ◽  
Peifu Tang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Femoral Neck ◽  
Femoral Neck Fracture ◽  
Element Analysis ◽  
Neck Fracture ◽  
Buttress Plate
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