scholarly journals Finite element analysis of different locking plate fixation methods for the treatment of ulnar head fracture

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Yue Zhang ◽  
Qin Shao ◽  
Chensong Yang ◽  
Changqing Ai ◽  
Di Zhou ◽  
...  
Keyword(s):  
Locking Plate ◽  
Plate Fixation ◽  
Relative Displacement ◽  
Dorsal Side ◽  
Bending Moments ◽  
Locking Plate Fixation ◽  
Element Analysis ◽  
Ulnar Side ◽  
Ulnar Head ◽  
Fixation System

Abstract Background Ulnar head fractures are increasingly higher with the growing proportion of the elderly people. Failure to achieve a stable anatomic reduction of ulna head fracture may lead to a distal radioulnar joint (DRUJ) dysfunction and nonunion of the distal radius. Due to the lack of the postoperative reporting outcomes and the biomechanical studies, it has not been well established about the optimal management of the comminuted distal ulna head fracture. Hence, the purpose of this study is to use finite element analysis to explain the advantages and disadvantages of ulnar-side locking plate fixation compared with dorsal-side locking plate fixation and its screw arrangement in the treatment of ulnar head fractures. Methods FE models of the ulnar head fracture and the models of ulnar-side locking plate and dorsal-side plate with two or three distal screws was constructed. In order to simulate forces acting on the ulnar and the osteosynthesis material during daily-life activity in subjects who underwent reconstructive surgery, we applied three loading conditions to each model, viz. 20 N axial compression, 50 N axial compression, 1 N∙m torsion moment, 1 N∙m lateral bending moments, and 1 N∙m extension bending moments. Under these conditions, values of the von Mises stress (VMS) distribution of the implant, peak VMS, the relative displacement of the head and shaft fragments between the fracture ends and the displacement and its direction of the models were investigated. Results The stress values of ulnar-side plates were lower than those of dorsal-side plates. And the ulnar-plate fixation system also has smaller maximum displacement and relative displacement. When adding a screw in the middle hole of the ulnar head, the values of model displacement and the peak stress in fixation system are lower, but it may evidently concentrate the stress on the middle screw. Conclusions In conclusion, our study indicated that ulnar-side locking plates resulted in a lower stress distribution in the plate and better stability than dorsal-side locking plates for ulnar head fracture fixation. Adding an additional screw to the ulnar head could increase the stability of the fixation system and provide an anti-torsion function. This study requires clinical confirmation of its practicality in the treatment of ulnar head fractures. This study requires clinical confirmation as to its practicality in the treatment of ulnar head fracture.

scholarly journals Finite element analysis of different locking-plate fixation methods for the treatment of ulnar head fracture

2021 ◽  
Author(s):  
Yue Zhang ◽  
Qin Shao ◽  
Chensong Yang ◽  
Changqing Ai ◽  
Di Zhou ◽  
...  
Keyword(s):  
Locking Plate ◽  
Plate Fixation ◽  
Relative Displacement ◽  
Dorsal Side ◽  
Bending Moments ◽  
Locking Plate Fixation ◽  
Element Analysis ◽  
Ulnar Side ◽  
Ulnar Head ◽  
Fixation System

Abstract Background: Ulnar head fractures are increasingly higher with the growing proportion of the elderly people. Failure to achieve a stable anatomic reduction of ulna head fracture may lead to a distal radioulnar joint (DRUJ) dysfunction and nonunion of the distal radius. Due to the lack of the postoperative reporting outcomes and the biomechanical studies, it has not been well established about the optimal management of the comminuted distal ulna head fracture. Hence, the purpose of this study is to use finite element analysis to explain the advantages and disadvantages of ulnar-side locking plate fixation compared with dorsal-side locking plate fixation and its screw arrangement in the treatment of ulnar head fractures.Methods: FE models of the ulnar head fracture and the models of ulnar-side locking plate and dorsal-side plate with two or three distal screws was constructed. In order to simulate forces acting on the ulnar and the osteosynthesis material during daily-life activity in subjects who underwent reconstructive surgery, we applied three loading conditions to each model, viz. 20 N axial compression, 50 N axial compression, 1 N∙m torsion moment, 1 N∙m lateral bending moments, and 1 N∙m extension bending moments. Under these conditions, values of the von Mises stress (VMS) distribution of the implant, peak VMS, the relative displacement of the head and shaft fragments between the fracture ends and the displacement and its direction of the models were investigated. Results: The stress values of ulnar-side plates were lower than those of dorsal-side plates. And the ulnar-plate fixation system also has smaller maximum displacement and relative displacement. When adding a screw in the middle hole of the ulnar head, the values of model displacement and the peak stress in fixation system are lower, but it may evidently concentrate the stress on the middle screw. Conclusions: In conclusion, our study indicated that ulnar-side locking plates resulted in a lower stress distribution in the plate and better stability than dorsal-side locking plates for ulnar head fracture fixation. Adding an additional screw to the ulnar head could increase the stability of the fixation system and provide an anti-torsion function. This study requires clinical confirmation of its practicality in the treatment of ulnar head fractures. This study requires clinical confirmation as to its practicality in the treatment of ulnar head fracture.

scholarly journals Finite Element Analysis of Different Locking-Plate Fixation Methods for the Treatment of Ulna Head Fracture

2020 ◽  
Author(s):  
Yue Zhang ◽  
Qin Shao ◽  
Chensong Yang ◽  
Changqing Ai ◽  
Di Zhou ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Locking Plate ◽  
Plate Fixation ◽  
Dorsal Side ◽  
Locking Plate Fixation ◽  
Element Analysis ◽  
Side Plate ◽  
Ulnar Side ◽  
Ulnar Head ◽  
Fixation System

Abstract Background: Ulnar head fractures are increasingly higher with the growing proportion of the elderly in the population. Failure to achieve stable anatomic reduction of ulna head fracture may lead to the DRUJ dysfunction and nonunion of distal radius. Due to the lack of the postoperative reporting outcomes and the biomechanical studies, it has not been well established about the optimal management of the comminuted distal ulna head fracture. This study aimed to explain the advantages and disadvantages of the ulnar-side locking plate fixation, compared with the dorsal-side one, and its screws arrangement in the treatment of the ulnar head fracture by using finite element analysis. Methods: FE models of the ulnar head fracture and the models of ulnar-side locking plate and dorsal-side plate with two or three distal screws was constructed. In order to simulate forces acting on the ulnar and the osteosynthesis material during daily-life activity in subjects who underwent reconstructive surgery, we applied three loading conditions to each model, viz. axial compression 20N, 50N, and torsion moments 1Nm. Under these conditions, values of the von Mises Stress (VMS) distribution of the implant, peak VMS, and model displacement were investigated. Results: Both the stress values and model displacement of ulnar-side plate were lower than those of dorsal-side plate. When adding a screw in the middle hole of the ulnar head, the values of model displacement and the peak stress in fixation system are lower, but it may evidently concentrate the stress on the middle screw. Conclusions: In conclusion, our study indicated that plating locking plate on ulnar side had lower stress distribution on the plate and better stability than on dorsal side in ulnar head fracture fixation. Adding the additional screw on the ulnar head could reduce the displacement of the fixation system and increase the stability of the fixation system. This study requires clinical confirmation as to its practicality in the treatment of ulnar head fracture.

scholarly journals Finite element analysis of different locking-plate fixation methods for the treatment of ulna head fracture

2020 ◽  
Author(s):  
Yue Zhang ◽  
Qin Shao ◽  
Chensong Yang ◽  
Changqing Ai ◽  
Di Zhou ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Locking Plate ◽  
Plate Fixation ◽  
Dorsal Side ◽  
Locking Plate Fixation ◽  
Element Analysis ◽  
Side Plate ◽  
Ulnar Side ◽  
Ulnar Head ◽  
Fixation System

Abstract Background: Ulnar head fractures are increasingly higher with the growing proportion of the elderly in the population. Failure to achieve stable anatomic reduction of ulna head fracture may lead to the DRUJ dysfunction and nonunion of distal radius. Due to the lack of the postoperative reporting outcomes and the biomechanical studies, it has not been well established about the optimal management of the comminuted distal ulna head fracture. This study aimed to explain the advantages and disadvantages of the ulnar-side locking plate fixation, compared with the dorsal-side one, and its screws arrangement in the treatment of the ulnar head fracture by using finite element analysis. Methods: FE models of the ulnar head fracture and the models of ulnar-side locking plate and dorsal-side plate with two or three distal screws was constructed. In order to simulate forces acting on the ulnar and the osteosynthesis material during daily-life activity in subjects who underwent reconstructive surgery, we applied three loading conditions to each model, viz. axial compression 20N, 50N, and torsion moments 1Nm. Under these conditions, values of the von Mises Stress (VMS) distribution of the implant, peak VMS, and model displacement were investigated. Results: Both the stress values and model displacement of ulnar-side plate were lower than those of dorsal-side plate. When adding a screw in the middle hole of the ulnar head, the values of model displacement and the peak stress in fixation system are lower, but it may evidently concentrate the stress on the middle screw. Conclusions: In conclusion, our study indicated that plating locking plate on ulnar side had lower stress distribution on the plate and better stability than on dorsal side in ulnar head fracture fixation. Adding the additional screw on the ulnar head could reduce the displacement of the fixation system and increase the stability of the fixation system. This study requires clinical confirmation as to its practicality in the treatment of ulnar head fracture.

Locking Plate Fixation System for Intracapsular Fracture Neck of Femur in Young Patients

2021 ◽  
Vol 23 (1) ◽  
pp. 27-32
Author(s):  
Islam Mubark ◽  
Mahmoud Nafady ◽  
Bahaa A. Motawea
Keyword(s):  
Femoral Head ◽  
Femoral Neck ◽  
Hip Replacement ◽  
Locking Plate ◽  
Plate Fixation ◽  
Young Patients ◽  
Locking Plate Fixation ◽  
Non Union ◽  
Mean Time ◽  
Fixation System

Background. Intra-capsular fractures of the femoral neck in young patients are almost always treated with surgical fixation to preserve the native hip anatomy and biomechanics. Multiple Cannulated hip screws and the sliding hip screw have been the hallmark fixation devices for these injuries. The use of locking cannulated hip screws to a side plate was developed to mitigate the biological and mechanical downfalls of these devices. To report the outcome following the use of a locking plate fixation system in the management of intracapsular fractures of the femoral neck in young patients. Material and methods. A case series study of all the patients treated in our institution between 2014 and 2017. All eligible patients with hip intracapsular fractures aged between 18 and 65 were treated with a proximal locking hip plate system. The main reported outcomes were union rate, failure of fixation, and development of avascular necrosis of the femoral head. Results: Fifty-six patients (36 men and 20 women) at a mean age of 39.1 years (range 20-65 years) completed 24 months’ follow-up. Mean time to surgery was 16 hours. No intraoperative complications were reported. The mean time to union was 15.9 weeks (range 12-23). Three patients (5.3%, one Garden type III, and two type IV) did not achieve union at 6 months. Two patients had revision surgery with valgus osteotomy and the third patient required total hip replacement because of screw penetration. Five patients (8.9%) developed avascular necrosis of the femoral head (2 patients Garden type III, and 3 patients Garden VI). Only two patients required conversion to total hip replacement. Conclusions. 1. The results in this study showed lower rates of non-union, AVN and secondary operation as compared to published data on both SCH and DHS. 2. It also compares favorably with results reported for dy­namic locking screw systems. 3. The study had few li­mitations, including lack of comparative groups. Also, when considering fracture classification subgroups, the unstable fracture pattern had higher rates of non-union and AVN. 4. This calls for a further larger number of studies dedicated to these fracture categories to ascertain long-term outcome with this type of fixation.

scholarly journals Comparison between external locking plate fixation and conventional external fixation for extraarticular proximal tibial fractures: a finite element analysis

2022 ◽  
Vol 17 (1) ◽  
Author(s):  
Dejan Blažević ◽  
Janoš Kodvanj ◽  
Petra Adamović ◽  
Dinko Vidović ◽  
Zlatko Trobonjača ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
External Fixation ◽  
Tibial Fracture ◽  
Locking Plate ◽  
Plate Fixation ◽  
Proximal Tibial Fracture ◽  
Locking Plate Fixation ◽  
Element Analysis ◽  
Maximum Stiffness

Abstract Background Good clinical outcomes for locking plates as an external fixator to treat tibial fractures have been reported. However, external locking plate fixation is still generally rarely performed. This study aimed to compare the stability of an external locking plate fixator with that of a conventional external fixator for extraarticular proximal tibial fractures using finite element analysis. Methods Three models were constructed: (1) external locking plate fixation of proximal tibial fracture with lateral proximal tibial locking plate and 5-mm screws (ELP), (2) conventional external fixation of proximal tibial fracture with an 11-mm rod and 5-mm Schanz screws (EF-11), and (3) conventional external fixation of a proximal tibial fracture with a 7-mm rod and 5-mm Schanz screws (EF-7). The stress distribution, displacement at the fracture gap, and stiffness of the three finite element models at 30-, 40-, 50-, and 60-mm plate–rod offsets from the lateral surface of the lateral condyle of the tibia were determined. Results The conventional external fixator showed higher stiffness than the external locking plate fixator. In all models, the stiffness decreased as the distance of the plate–rod from the bone surface increased. The maximum stiffness was 121.06 N/mm in the EF-11 model with 30-mm tibia–rod offset. In the EF-7 model group, the maximum stiffness was 40.00 N/mm in the model with 30-mm tibia–rod offset. In the ELP model group, the maximum stiffness was 35.79 N/mm in the model with 30-mm tibia–plate offset. Conclusions Finite element analysis indicated that external locking plate fixation is more flexible than conventional external fixation and can influence secondary bone healing. External locking plate fixation requires the placement of the plate as close as possible to the skin, which allows for a low-profile design because the increased distance from the plate to the bone can be too flexible for bone healing. Further experimental mechanical model tests are necessary to validate these finite element models, and further biological analysis is necessary to evaluate the effect of external locking plate fixation on fracture healing.

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