scholarly journals Modified F configuration in the treatment of Pauwels type III femoral neck fracture: a finite element analysis

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Shiyuan Lin ◽  
Jie Shang ◽  
Baizhou Xing ◽  
Biao Wu ◽  
Rong Peng ◽  
...  
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Femoral Neck ◽  
Femoral Neck Fracture ◽  
Young Patients ◽  
Cannulated Screw ◽  
Type Iii ◽  
Fracture Surfaces ◽  
Neck Fracture ◽  
Maximum Crack

Abstract Background The optimal treatment of Pauwels type III femoral neck fracture (FNF) 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 FNF: a: the traditional inverted triangular parallel cannulated screw (PCS) 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 derotational screw (DHS + DS) 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 configurations, 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 FNF compared to those using traditional inverted triangular PCS, the F-technique configuration or DHS + DS, providing a new choice for the treatment of FNFs.

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 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.

Proposal for a New Fixation Method for Pauwels Type III Femoral Neck Fracture-Metaphyseal Stem: A Finite-Element Analysis

2021 ◽  
Author(s):  
Anderson Freitas ◽  
Fabrício Reichert Barin ◽  
Leonardo Rigobello Battaglion ◽  
Hélio Ismael da Costa ◽  
Eduardo Duarte Santos ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Femoral Neck ◽  
Femoral Neck Fracture ◽  
Fixation Method ◽  
Element Analysis ◽  
Type Iii ◽  
Neck Fracture

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 ◽  
Vol 16 (1) ◽  
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.

Finite element analysis of the effect of cannulated screw placement and drilling frequency on femoral neck fracture fixation

Injury ◽  
2014 ◽  
Vol 45 (12) ◽  
pp. 2045-2050 ◽  
Author(s):  
Jiong Mei ◽  
Shiwei Liu ◽  
Guangyao Jia ◽  
Xueliang Cui ◽  
Chao Jiang ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Femoral Neck ◽  
Femoral Neck Fracture ◽  
Fracture Fixation ◽  
Cannulated Screw ◽  
Screw Placement ◽  
Element Analysis ◽  
Neck Fracture

scholarly journals Optimum Configuration of Cannulated Compression Screws for the Fixation of Unstable Femoral Neck Fractures: Finite Element Analysis Evaluation

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Jiantao Li ◽  
Menglin Wang ◽  
Jianfeng Zhou ◽  
Lin Han ◽  
Hao Zhang ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Femoral Neck ◽  
Femoral Neck Fracture ◽  
Peak Stress ◽  
Femoral Neck Fractures ◽  
Proximal Fragment ◽  
Element Analysis ◽  
Neck Fracture

Objectives. In the present study, we evaluated the mechanical outcome of different configurations of cannulated compression screws for the fixation of Pauwels type III femoral neck fracture and the stress distribution around the holes corresponding to fixation protocol after screws removal. Methods. The Pauwels type III of femoral neck fracture was created in 3-matic software and the models of cannulated compression screws were constructed using UG-NX software. Five fixation systems were assembled to the fracture models. Abaqus software was used to perform the process of finite element analysis. Values of stress distribution, maximum stress, model principal strains of proximal fragment, and stress distribution around the holes of femur model were recorded. Results. Stress of cannulated compression screws was intensely focused on the middle area of the screw near the fragment of each group. Inverted triangle model showed the highest peak stress on screws under different phases of load. Each screw dispersed some stresses, but at least one underwent the peak stress. Fracture model fixed by inverted triangle configuration showed the lowest volume of yielding strain in the proximal fragment. The area of higher stress around the holes was largest after triangle screws removal when compared with other four models. Conclusions. Our study indicated that different cannulated compression screws fixation configurations for the unstable femoral neck fractures showed the different mechanical efficiency. Inverted triangular configuration showed the mechanical advantage and being less likely to cutout. The fixation strategy of triangle configuration was least recommended if patients tended to remove the implants.

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