Biomechanical analysis of femoral fracture fixation using the expert adolescent lateral femoral nail system

Femoral fracture in adolescents is a severe injury. Recent studies of intramedullary nail fixation with rigid titanium alloy helical nail viz. Expert adolescent lateral femoral nail (ALFN) have reported good results. However, there is no in vitro biomechanical data available on this nail in the lite...

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Bibliographic Details
Main Author: Angadi, Darshan Srishail
Published: University of Birmingham 2017
Subjects:
610
Online Access:https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.731930
Description
Summary:Femoral fracture in adolescents is a severe injury. Recent studies of intramedullary nail fixation with rigid titanium alloy helical nail viz. Expert adolescent lateral femoral nail (ALFN) have reported good results. However, there is no in vitro biomechanical data available on this nail in the literature. Experimental testing and finite element analysis (FEA) were used to establish the stiffness parameters of small composite femurs with simulated fractures stabilised using ALFN. In comparison to intact femur, construct stiffness ranged from maximum (114%) to minimum (20%) for healed fracture and segmental fracture, respectively. Simulation testing in SolidWorksTM was performed with validated FEA model to evaluate the effect of clinical and implant factors. Maximum predicted stress in the distal interlocking screw remained in an acceptable range (160.25 - 188.51 MPa) irrespective of the level of femoral shaft fracture with a relative decrease in stress values as the fracture callus healed over a 16 week period. The relative angle between the ALFN and proximal interlocking screw and implant material were two significant factors influencing stress at the interlocking screw and nail interface. In conclusion, a rigid helical titanium alloy femoral intramedullary nail can perform satisfactorily under physiological loading conditions experienced in the perioperative period.