Andrew Mcdougall New

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Failure mechanisms of the resurfaced femoral head include femoral neck fracture in the short-term and stress shielding and implant loosening in the long-term. In this study, finite element simulations of the resurfaced femur considering a debonded implant-cement interface, variable stem-bone interface conditions, and bone remodelling were used to study load(More)
This paper describes the application of probabilistic design methods to the analysis of the behaviour of an uncemented total hip replacement femoral component implanted in a proximal femur. Probabilistic methods allow variations in factors which control the behaviour of the implanted femur (the input parameters) to be taken into account in determining the(More)
Human bone marrow contains bone progenitor cells that arise from multipotent mesenchymal stem cells. Seeding bone progenitor cells onto a scaffold can produce a 3D living composite with significant mechanical and biological potential. This article details laboratory and clinical findings from two clinical cases, where different proximal femoral conditions(More)
With the demographics of an aging population the incidence of revision surgery is rapidly increasing. Clinical imperatives to augment skeletal tissue loss have brought mesenchymal stem cells to the fore in combination with the emerging discipline of tissue engineering. Impaction bone grafting for revision hip surgery is a recognized technique to(More)
The complications of impaction bone grafting in revision hip replacement includes fracture of the femur and subsidence of the prosthesis. In this in vitro study we aimed to investigate whether the use of vibration, combined with a perforated tamp during the compaction of morsellised allograft would reduce peak loads and hoop strains in the femur as a(More)
BACKGROUND Although the short-term performance of modern resurfacing hip arthroplasty is impressive, the long-term performance is still unknown. It is hypothesised that bone remodelling and the resulting changes in stress/strain distribution within the resurfaced femur influence the risk of fixation failure. METHOD Three-dimensional finite element models(More)
The demographic challenges of an increasingly aging population emphasize the need for innovative approaches to skeletal reconstruction to augment and repair skeletal tissue lost as a consequence of implant loosening, trauma, degeneration or in situations involving revision surgery requiring bone stock. These clinical imperatives to augment skeletal tissue(More)
In the present study, a probabilistic finite element tool was assessed using an uncemented total hip replacement model. Fully bonded and frictional interfaces were investigated for combinations of three proximal femurs and two implant designs, the Proxima short stem and the IPS hip stem prostheses. The Monte Carlo method was used with two performance(More)
Nomograms derived from mathematical analysis indicate that the level of malunion is the most important determinant of changes in the moment arm of the knee, the plane of the ankle and alterations in limb length. Testing in five patients undergoing reconstruction showed a mean error of postoperative limb length of 2.2 mm (SD 0.8 mm), knee moment arm of 4.7(More)
Ceramic hip resurfacing may offer improved wear resistance compared to metallic components. The study is aimed at investigating the effects of stiffer ceramic components on the stress/strain-related failure mechanisms in the resurfaced femur, using three-dimensional finite element models of intact and resurfaced femurs with varying stem–bone interface(More)