Biomechanical analyses of static and dynamic fixation techniques of retrograde interlocking femoral nailing using nonlinear finite element methods

Kao Shang Shih, Ching Chi Hsu, Tzu Pin Hsu, Sheng Mou Hou, Chen Kun Liaw

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

Femoral shaft fractures can be treated using retrograde interlocking nailing systems; however, fracture nonunion still occurs. Dynamic fixation techniques, which remove either the proximal or distal locking screws, have been used to solve the problem of nonunion. In addition, a surgical rule for dynamic fixation techniques has been defined based on past clinical reports. However, the biomechanical performance of the retrograde interlocking nailing systems with either the traditional static fixation technique or the dynamic fixation techniques has not been investigated by using nonlinear numerical modeling. Three-dimensional nonlinear finite element models were developed, and the implant strength, fixation stability, and contact area of the fracture surfaces were evaluated. Three types of femoral shaft fractures (a proximal femoral shaft fracture, a middle femoral shaft fracture, and a distal femoral shaft fracture) fixed by three fixation techniques (insertion of all the locking screws, removal of the proximal locking screws, or removal of the distal locking screws) were analyzed. The results showed that the static fixation technique resulted in sufficient fixation stability and that the dynamic fixation techniques decreased the failure risk of the implant and produced a larger contact area of the fracture surfaces. The outcomes of the current study could assist orthopedic surgeons in comprehending the biomechanical performances of both static and dynamic fixation techniques. In addition, the surgeons could also select a fixation technique based on the specific patient situation using the numerical outcomes of this study.

Original languageEnglish
Pages (from-to)456-464
Number of pages9
JournalComputer Methods and Programs in Biomedicine
Volume113
Issue number2
DOIs
Publication statusPublished - Feb 1 2014
Externally publishedYes

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Keywords

  • Dynamization
  • Femoral fracture
  • Finite element analysis
  • Retrograde interlocking nail

ASJC Scopus subject areas

  • Software
  • Computer Science Applications
  • Health Informatics

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