The Role Of Osteocytes In Particle Induced Osteolysis
Funder
National Health and Medical Research Council
Funding Amount
$457,196.00
Summary
Hip replacements often fail due to the loss of adjacent bone. Metal or polyethylene particles are produced as the prosthesis bearing surface wears but how do these particles lead to bone loss? Our work suggests involvement of osteocytes within the bone mineral, which are increasingly understood to drive bone physiology and pathology. We will explore the role of the osteocytes by examining their response to particles, which may identify a new target to prevent particle-induced bone loss.
We will seek to address an important clinical problem in orthpaedics, namely the bone loss that commonly occurs around joint replacement prostheses. Termed peri-prosthetic osteolysis (PO), this bone loss can result in the loosening and ultimate failure and need for revision of the artificial joint components. PO is thought to be caused by the body's reaction to wear particles generated from the articulating surface of the prosthesis. However, it has not previously been possible to accurately exp ....We will seek to address an important clinical problem in orthpaedics, namely the bone loss that commonly occurs around joint replacement prostheses. Termed peri-prosthetic osteolysis (PO), this bone loss can result in the loosening and ultimate failure and need for revision of the artificial joint components. PO is thought to be caused by the body's reaction to wear particles generated from the articulating surface of the prosthesis. However, it has not previously been possible to accurately explore the relationship between prothesis wear and PO, or the progression of PO, because of a lack of techniques to image and measure the volume of PO around metal prosthesis components. We have developed a means to accurately and reproducibly measure the volume of bone loss, using CT, and will do so longitudinally in joint replacement patients to obtain the first information about the progression of PO. New computer based methods will be used concurrently to relate prosthesis wear and migration parameters to PO. Patients who come to surgery for replacement of failed prostheses will be investigated further by analysis of the tissues involved in the bone loss around prostheses. Basic science experiments will seek to understand the underlying causes of PO and the findings will be important in interpreting the clinical results. An animal model will be used to seek approaches to inhibiting the pathological response to wear particles. The significance of these studies is that they will lead to improved outcomes for joint replacement patients, increasing the interval to revision surgery, which is both extremely costly and brings an attendant morbidity and mortality.Read moreRead less
Determination Of Irradiation Dose Efficacy For Use In Impaction Grafting At Revision Joint Replacement
Funder
National Health and Medical Research Council
Funding Amount
$411,517.00
Summary
Primary hip replacement is a successful intervention for hip disease, but 10-15% of hip prostheses fail and require revision surgery within 10-15 years. At the time of revision, significant bone loss around the failed prosthesis is not uncommon. A bone reconstruction procedure, called impaction grafting, where donor bone is minced and placed in the areas of deficient bone before implanting the new prosthesis, has shown to give good results at more than ten years in some centres. A high incidence ....Primary hip replacement is a successful intervention for hip disease, but 10-15% of hip prostheses fail and require revision surgery within 10-15 years. At the time of revision, significant bone loss around the failed prosthesis is not uncommon. A bone reconstruction procedure, called impaction grafting, where donor bone is minced and placed in the areas of deficient bone before implanting the new prosthesis, has shown to give good results at more than ten years in some centres. A high incidence of early complications of this procedure have included loss of fixation within the bone. Fracture of the bone around prostheses has also reported in some centres. These events require more surgery, putting the patient at higher risk greater complications and longer rehabilitations. Recent improvements in surgical technique and donor bone preparation have improved results. A current debate questions whether the dose of irradiation can be reduced from 25 kGy, while maintaining sterility of allografts. The risk of bacterial contamination in allografts is low, and irradiation reduces the mechanical strength of the graft, contributing to complications when irradiated bone is used. The benefits of decontaminating the bone may be outweighed by the higher risk for failure due to poor bone quality and resulting prosthesis instability. We will use ISO standards to test the validity of radiation dose for sterilising bone ex vivo. In the absence of controlled human studies, our aim is also to compare the results of impaction grafting with non-irradiated bone versus bone irradiated at current doses used by Australian bone banks, and lower doses indicated by ex vivo testing. We will use a large animal model of revision hip replacement, with precise measures of prosthesis stability. The results of this study will guide clinical decisions regarding the efficacy of current bone graft preparation procedures and the use of irradiated bone in human hip replacement surgery.Read moreRead less
The Risks And Benefits Of Contemporary Total Hip Replacement
Funder
National Health and Medical Research Council
Funding Amount
$493,530.00
Summary
The number of hip replacements undertaken in Australia is steadily increasing. The most common complications of hip replacements are dislocation and loosening due to bone loss around the implant, requiring complex and expensive revision surgery. This study will investigate the incidence of dislocation and, using a new diagnostic imaging technique, the incidence and amount of bone loss around a relatively new prosthetic material, the outcomes of which are not known despite its increasing use.
Identifying Target Genes For Novel Anti-epileptic Therapies In The Mouse
Funder
National Health and Medical Research Council
Funding Amount
$469,802.00
Summary
Epilepsy is a disease which affects 2-4% of the population. There are a wide range of drugs available to treat the condition but there is consistently 30-40% of patients who do not respond well to any of these drugs and who continue to have seizures. The reason that there are no drugs available for these people is that most of the drugs available have been designed along the same principles. A new set of principles is needed to develop new drugs which will be able to treat those people not respo ....Epilepsy is a disease which affects 2-4% of the population. There are a wide range of drugs available to treat the condition but there is consistently 30-40% of patients who do not respond well to any of these drugs and who continue to have seizures. The reason that there are no drugs available for these people is that most of the drugs available have been designed along the same principles. A new set of principles is needed to develop new drugs which will be able to treat those people not responding to current therapy. This project is designed to identify new biologic pathways which may be interrupted with drugs to prevent seizures in people with epilepsy. This project uses a procedure to induce mutations into genes in mice and then screens for mice which do not seize when challenged with a drug which generates seizures in mice. Genetic studies will identify the mutated genes and these will be used as potential targets for new therapies or will identify new biological pathway which should expand the use of future anti-epileptic drugs.Read moreRead less
Targeting RCAN1 To Treat Type 2 Diabetes And Obesity
Funder
National Health and Medical Research Council
Funding Amount
$814,468.00
Summary
Obesity and impaired insulin secretion are significant contributors to Type 2 diabetes. In this project we demonstrate that a protein called RCAN1 contributes to both fat mass and insulin secretion and that this contribution is exacerbated in obesity and in Type 2 diabetes. We will identify how RCAN1 controls these major metabolic pathways with outcomes including the development of new therapeutics for obesity and Type 2 diabetes.
Regulation Of Key Pathways Causing Peri-implant Bone Loss.
Funder
National Health and Medical Research Council
Funding Amount
$403,639.00
Summary
The failure of bone prostheses is becoming a major health problem in our aging population. Despite the impressive success of joint replacement surgery, a significant number of arthroplasties fail. It is now apparent that most implants fail due to bone loss around them which leads to loosening. This project aims to obtain a better understanding of the causes of implant failure and find ways to extend the life of these implants .
The Central Australian Heart Protection Study: A Randomised Trial Of Nurse-Led, Family Based Secondary Prevention Of Acute Coronary Syndromes
Funder
National Health and Medical Research Council
Funding Amount
$1,923,630.00
Summary
Despite the high burden of cardiovascular diseases among Indigenous Australians, few intervention trials have sought to evaluate novel approaches to reducing differential outcomes in this vulnerable group. The Central Australian Heart Protection Study seeks to test the effectiveness of a nurse-led, family based education and assessment program in reducing the incidence of poor outcomes in indigenous and non-indigenous patient’s following an Acute Coronary Syndrome (ACS).
A model of the mind which explains the role of emotions in normal cognition and affective disorder. Depression is recognised as one of the most burdensome diseases in Australia. Though we of course make no claims, as philosophers, to cure depression our contribution is to engage philosophy productively with a vital national area of empirical research. The other area of national benefit is to consolidate Australia's developing reputation as a site for the involvement of philosophy in interdiscipl ....A model of the mind which explains the role of emotions in normal cognition and affective disorder. Depression is recognised as one of the most burdensome diseases in Australia. Though we of course make no claims, as philosophers, to cure depression our contribution is to engage philosophy productively with a vital national area of empirical research. The other area of national benefit is to consolidate Australia's developing reputation as a site for the involvement of philosophy in interdisciplinary projects which link the humanities to the sciences. Furthermore, with the project's anchoring in the humanities, there is hope that a focus on, and increased understanding of, depression will have flow-on effects in the Australian community that will help ease the stigmatisation that is still felt by many of its sufferers.Read moreRead less