Plate fixation optimization for distal femoral fractures with segmental bone loss: Defining the preferred screw distribution using finite element analysis.

Injury

Herston Biofabrication Institute, Metro North Hospital and Health Service, Brisbane, QLD, 4029, Australia; Department of Orthopaedic Surgery, The Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia; Orthopaedic Research Centre of Australia, Brisbane, QLD, Australia; Limb Reconstruction Unit, Macquarie University Hospital, Sydney, NSW, Australia.

Published: February 2024

Objectives: Distal femur fractures can exhibit extensive comminution, and open fractures may result in bone loss. These injuries are under high mechanical demands when stabilized with a lateral locked plate (LLP), and are at risk of non-union or implant failure. This study investigates the optimal LLP screw configuration for distal femur fractures with a large metadiaphyseal gap of 5 cm.

Methods: A finite element (FE) model, validated against experimentally measured strains and displacement, evaluated pull-out forces and stress concentration on typical implants under clinical conditions corresponding with the 10 % point during the stance phase of the gait cycle.

Results: Maximum stress was up to 83 % less when the ratio (Cp) between the proximal screw-distribution-length and the distance of the first screw to the fracture was less than 0.2; maximum pull-out force was 99 % less when this ratio was higher than 0.4.

Conclusions: Screw configuration based on either normal or osteopenic bone quality plays an important role in determining the risk of construct failure for a major (50 mm) distal femoral metadiaphyseal segmental defect. This study provides valuable information when planning definitive fixation for distal femur fractures with extensive comminution or segmental bone defects, to mitigate the risk of implant failure and subsequent nonunion.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.injury.2023.111079DOI Listing

Publication Analysis

Top Keywords

distal femur
12
femur fractures
12
distal femoral
8
segmental bone
8
bone loss
8
finite element
8
extensive comminution
8
implant failure
8
screw configuration
8
distal
5

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!