A novel strain-based fracture-healing algorithm for in silico trials -application to femoral fracture treatment
File(s)
Author(s)
Morgan, George
Type
Thesis
Abstract
Poor healing outcomes of bone fractures can result in revision surgeries, permanent mobility loss, or death. As research into optimal fracture treatments has progressed, rates of poor outcomes have decreased for many fracture types. Other fracture types continue to have high rates of morbidity and mortality, however, as traditional research methods have failed to identify optimal treatments. The aim of this work was to create a computational tool which is capable of predicting the fracture-healing sequence in response to the mechanical environment of a simple fracture.
A novel fracture-healing algorithm was developed which used minimum and maximum principal strains as its mechanical inputs. The limitations of previously published fracture-healing algorithms were addressed. The novel algorithm was validated against published experimental data of ovine fractures and was demonstrated to be independent of the initially-specified callus domain size. A sensitivity analysis of the algorithm demonstrated its robustness to its input parameters.
The algorithm was used to compare the effect of different rehabilitation-regimes on fracture healing in a model of a large-gap fracture stabilised with a fixed free-movement distance type fixator. This analysis indicated that a constant high stability rehabilitation-regime produces the shortest healing times for the tested fracture and fixator types. The algorithm was also expanded from an axisymmetric to a 3-D implementation in order to model a mid-shaft fracture of a realistic femur. Intramedullary nailing and lateral locking plate fixation were modelled and the fracture-healing algorithm accurately predicted the differences in callus development caused by the two fixation treatments.
The novel algorithm presented within this thesis allows for the in silico investigation of fracture-healing treatments and rehabilitation-regimes through its implementation in in silico trials.
A novel fracture-healing algorithm was developed which used minimum and maximum principal strains as its mechanical inputs. The limitations of previously published fracture-healing algorithms were addressed. The novel algorithm was validated against published experimental data of ovine fractures and was demonstrated to be independent of the initially-specified callus domain size. A sensitivity analysis of the algorithm demonstrated its robustness to its input parameters.
The algorithm was used to compare the effect of different rehabilitation-regimes on fracture healing in a model of a large-gap fracture stabilised with a fixed free-movement distance type fixator. This analysis indicated that a constant high stability rehabilitation-regime produces the shortest healing times for the tested fracture and fixator types. The algorithm was also expanded from an axisymmetric to a 3-D implementation in order to model a mid-shaft fracture of a realistic femur. Intramedullary nailing and lateral locking plate fixation were modelled and the fracture-healing algorithm accurately predicted the differences in callus development caused by the two fixation treatments.
The novel algorithm presented within this thesis allows for the in silico investigation of fracture-healing treatments and rehabilitation-regimes through its implementation in in silico trials.
Version
Open Access
Date Issued
2024-09-24
Date Awarded
01/03/2025
License URL
Advisor
Masouros, Spyros
Ramasamy, Arul
Sponsor
Engineering and Physical Sciences Research Council
Grant Number
EP/T51780X/1
Publisher Department
Department of Bioengineering
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)