Thesis
Effect of an orthogonal locking plate and screw configuration on locking construct stiffness and plate strain in an in vitro fracture-gap model
Masters by Research, Murdoch University
2024
Abstract
Objective: (1) To compare stiffness and strain of an in vitro fracture-gap model secured with a primary 3.5 mm locking compression plate (LCP) at three primary plate working lengths without and with an orthogonal 2.7 mm LCP. (2) To evaluate the effect of screw number in the primary and orthogonal plate on bending and torsional stiffness in the same model.
Study Design: (1) Primary plate screw configurations modelled short, medium, and long working lengths (SWL, MWL, LWL). Construct stiffness with and without an orthogonal plate during nondestructive four-point bending and torsion, and primary plate surface strain measured during bending, were analysed. (2) Five screw configurations were modelled with two-two, three-two, three-three, fourthree, and four-four screws per fragment in the primary and orthogonal plate, respectively. Construct stiffness across screw configurations was analysed during non-destructive fourpoint bending and torsion.
Results: Single plate construct stiffness was significantly, incrementally, lower in bending and torsion as working length extended. Addition of an orthogonal plate resulted in significantly higher bending stiffness for SWL, MWL and LWL (P<0.05) and torsional stiffness for MWL and LWL (P<0.05). Strain was significantly, incrementally, higher as working length extended for single plate constructs. Addition of an orthogonal plate significantly lowered strain for SWL, MWL, and LWL constructs (P<0.01). There was no significant difference across screw number in bending or torsional stiffness.
Conclusion: Addition of an orthogonal plate resulted in higher bending and torsional stiffness and lower primary plate strain in this in vitro model. Working length had an inverse relationship with construct stiffness and a direct relationship with strain. The inverse effect of working length on construct stiffness was completely mitigated by orthogonal plate application in bending and modified in torsion. More than two bicortical screws in the primary and orthogonal LCP per fragment did not result in higher stiffness.
Details
- Title
- Effect of an orthogonal locking plate and screw configuration on locking construct stiffness and plate strain in an in vitro fracture-gap model
- Authors/Creators
- Brett W de Bruyn
- Contributors
- Mark Glyde (Supervisor)Giselle Hosgood (Supervisor) - Murdoch University, School of Veterinary Medicine
- Awarding Institution
- Murdoch University; Masters by Research
- Identifiers
- 991005662068407891
- Murdoch Affiliation
- School of Veterinary Medicine
- Resource Type
- Thesis
- Note
- Research Masters with Training of Murdoch University
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