{"title":"Numerical comparison of the intramedullary nail for the fixation of different proximal femoral fractures","authors":"Yen-Nien Chen PhD , Chih-Wei Chang PhD , Kuo-Chih Su PhD , Chia-Jung Chang PhD","doi":"10.1016/j.clinbiomech.2025.106438","DOIUrl":null,"url":null,"abstract":"<div><h3>Background</h3><div>This study aimed to compare the mechanical responses, including the stability and implant stress, of different proximal femoral fractures stabilized with an intramedullary system by finite element simulation. Furthermore, the effect of number of the lag screws, including one and two screws, was also investigated.</div></div><div><h3>Methods</h3><div>A numerical hip model was created first, and then four different types of proximal femoral fractures—namely femoral neck, intertrochanteric, reverse intertrochanteric, and subtrochanteric fractures—were employed in this study. An intramedullary nail system was used to fix the four fracture types. Furthermore, two different number of lag screws, either one bigger or two smaller, was also compared. The peak loading of the femur in level walking was used for comparison.</div></div><div><h3>Findings</h3><div>The results showed that both the peak displacement and the gap opening distance in the reversed intertrochanteric fracture were obviously higher than in the other fractures. Additionally, the peak equivalent stress of the intramedullary nail in the reversed intertrochanteric fracture was the highest among all the fractures. The stress on the nail in cases of reversed intertrochanteric fracture was 4.6 times (ranging from 132.9 to 616.8 MPa) and 4.4 times (ranging from 126 to 556 MPa) higher than in intertrochanteric fractures with one and two lag screws, respectively.</div></div><div><h3>Interpretation</h3><div>The intramedullary nail is a mechanically effective device for the fixation of proximal femoral fractures. However, to avoid the nail breakage the postoperative rehabilitation process for reversed intertrochanteric fracture should be slower compared to the neck, intertrochanteric and subtrochanteric fractures.</div></div>","PeriodicalId":50992,"journal":{"name":"Clinical Biomechanics","volume":"122 ","pages":"Article 106438"},"PeriodicalIF":1.4000,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Clinical Biomechanics","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0268003325000105","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"ENGINEERING, BIOMEDICAL","Score":null,"Total":0}
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Abstract
Background
This study aimed to compare the mechanical responses, including the stability and implant stress, of different proximal femoral fractures stabilized with an intramedullary system by finite element simulation. Furthermore, the effect of number of the lag screws, including one and two screws, was also investigated.
Methods
A numerical hip model was created first, and then four different types of proximal femoral fractures—namely femoral neck, intertrochanteric, reverse intertrochanteric, and subtrochanteric fractures—were employed in this study. An intramedullary nail system was used to fix the four fracture types. Furthermore, two different number of lag screws, either one bigger or two smaller, was also compared. The peak loading of the femur in level walking was used for comparison.
Findings
The results showed that both the peak displacement and the gap opening distance in the reversed intertrochanteric fracture were obviously higher than in the other fractures. Additionally, the peak equivalent stress of the intramedullary nail in the reversed intertrochanteric fracture was the highest among all the fractures. The stress on the nail in cases of reversed intertrochanteric fracture was 4.6 times (ranging from 132.9 to 616.8 MPa) and 4.4 times (ranging from 126 to 556 MPa) higher than in intertrochanteric fractures with one and two lag screws, respectively.
Interpretation
The intramedullary nail is a mechanically effective device for the fixation of proximal femoral fractures. However, to avoid the nail breakage the postoperative rehabilitation process for reversed intertrochanteric fracture should be slower compared to the neck, intertrochanteric and subtrochanteric fractures.
期刊介绍:
Clinical Biomechanics is an international multidisciplinary journal of biomechanics with a focus on medical and clinical applications of new knowledge in the field.
The science of biomechanics helps explain the causes of cell, tissue, organ and body system disorders, and supports clinicians in the diagnosis, prognosis and evaluation of treatment methods and technologies. Clinical Biomechanics aims to strengthen the links between laboratory and clinic by publishing cutting-edge biomechanics research which helps to explain the causes of injury and disease, and which provides evidence contributing to improved clinical management.
A rigorous peer review system is employed and every attempt is made to process and publish top-quality papers promptly.
Clinical Biomechanics explores all facets of body system, organ, tissue and cell biomechanics, with an emphasis on medical and clinical applications of the basic science aspects. The role of basic science is therefore recognized in a medical or clinical context. The readership of the journal closely reflects its multi-disciplinary contents, being a balance of scientists, engineers and clinicians.
The contents are in the form of research papers, brief reports, review papers and correspondence, whilst special interest issues and supplements are published from time to time.
Disciplines covered include biomechanics and mechanobiology at all scales, bioengineering and use of tissue engineering and biomaterials for clinical applications, biophysics, as well as biomechanical aspects of medical robotics, ergonomics, physical and occupational therapeutics and rehabilitation.