The Design, Development And Clinical Assessment Of A New Metacarpophalangeal Joint Prosthesis
Funder
National Health and Medical Research Council
Funding Amount
$188,450.00
Summary
Rheumatoid arthritis is a crippling form of arthritis that affects many people in the community. It commonly involves the finger joints in the hands resulting in deformity, pain and subsequent loss of function. There have been implants designed for finger joint replacement, but unfortunately these implants have had only moderate benefits and can break and lead to further joint destruction resulting in the worsening of deformity and pain. A new implant for finger joint replacement has been develo ....Rheumatoid arthritis is a crippling form of arthritis that affects many people in the community. It commonly involves the finger joints in the hands resulting in deformity, pain and subsequent loss of function. There have been implants designed for finger joint replacement, but unfortunately these implants have had only moderate benefits and can break and lead to further joint destruction resulting in the worsening of deformity and pain. A new implant for finger joint replacement has been developed. This implant has several potential advantages. Firstly the unique design acts to prevent recurring deformity in the fingers with rheumatoid disease while allowing functional motion. Secondly, it is thought that patients will return to function earlier and avoid the need for further finger surgery as this implant design relies less on the tissues around it for stability. The purpose of this study is to investigate the biomechanical and clinical benefits of this new implant for finger joint replacement. The new design will undergo specific laboratory tests and be used in a clinical trial to quantify the therapeutic benefits it provides to patients with rheumatoid arthritis.Read moreRead less
At present the failure rate of joint replacement is unacceptably high and will continue to rise due to the ageing and active life styles of the baby-boomer generation, placing an increasing burden on the health budget. We have developed a new bioactive material with improved mechanical-biological properties for bone regeneration. We will modify the surface of the currently used orthopaedic implants with this bioactive material to promote permanent fixation of the prosthesis to the bone.
Radiostereometric Analysis Of The Effect Of A Large Articulation On Prosthetic Wear And Migration After Hip Replacement
Funder
National Health and Medical Research Council
Funding Amount
$192,186.00
Summary
At total hip replacement, there has been a recent trend to use prostheses with a larger ball and liner in the socket. This may decrease the risk of post-operative dislocation, but may also increase the amount of wear, leading to bone loss and loosening of prostheses, which may then require replacement. This project will use a special type of x-ray to determine whether wear and movement of these new prostheses is clinically acceptable, so that they can be used with confidence in patients.
Mechanisms Of Bone Formation At The Device/tissue Interface: Role Of Biomaterial Surface Chemistry Modification
Funder
National Health and Medical Research Council
Funding Amount
$489,375.00
Summary
In 1992 300,000 prosthetic devices, artificial hips and knees were implanted into patients in a global market worth $2.1 billion. Growth in this field of medicine has been exceptional with now more than 1 million implants carried out each year. In 1998-99, 38,512 artificial hips and knees were implanted in Australia alone, with approximately 10% of these replacing older, failed implants. Since joint replacements provide great benefits for the patient considerable health funding is required for j ....In 1992 300,000 prosthetic devices, artificial hips and knees were implanted into patients in a global market worth $2.1 billion. Growth in this field of medicine has been exceptional with now more than 1 million implants carried out each year. In 1998-99, 38,512 artificial hips and knees were implanted in Australia alone, with approximately 10% of these replacing older, failed implants. Since joint replacements provide great benefits for the patient considerable health funding is required for joint replacements. However, failure of the implants is a major concern to the patient and financially to our health system, especially with the ever increasing life expectancy of our population. The long-and short-term success of an implant depends on the healthy support of the surrounding bone. This study aims to find ways of improving the attachment of healthy bone to the implant by modifying the surface characteristics of the implant. We will modify the surface chemistry of biomaterials with divalent cations, such as magnesium, which is known to play a critical role in bone remodelling and skeletal development. Our goal is to improve the formation of healthy bone that will promote a rapid and permanent fixation of implant into skeletons. This study goes further to study the factors, inside the cell, on the cell surface and secreted by the cell, which promote this attachment. Once these factors are identified, it should be possible to alter implant surfaces in ways to improve stability. In this proposal we will use novel bioceramic coatings and ion beam technologies. This study will not only improve our understanding of the interactions of bone and implant but also identify ways of improving implants to benefit the patient's quality of life and reduce costs in this important heath areaRead moreRead less
The Prognostic Significance Of Obesity In Joint Arthroplasty
Funder
National Health and Medical Research Council
Funding Amount
$57,803.00
Summary
There are over 55,000 hip and knee joint replacements performed in Australia every year and the number is rising. The incidence of obesity is also rising. Higher risk of surgical complications following joint replacement surgery has been reported in obese patients. It is therefore imperative that we determine the impact obesity has on the outcome of joint replacement surgery in order to determine if treatment needs to be modified.
Prevention And Treatment Of Bone Infection With CSA-90
Funder
National Health and Medical Research Council
Funding Amount
$350,983.00
Summary
Bone infections are a major challenge to treat, especially with the rise of drug resistant “superbugs”. We have access to a new agent, CSA-90, that has dual properties of being anti-microbial (antibiotic) and helps encourage bone growth. This project aims to expand upon our prior research and test CSA-90 for the treatment of chronic bone infections. We will also look at applying this technology to joint replacements and this drug may be particularly useful for coating orthopaedic implants.
Cartilage Destruction In Joint Disease: Studies With ADAMTS-4 And ADAMTS-5 Deficient Mice
Funder
National Health and Medical Research Council
Funding Amount
$540,600.00
Summary
In healthy joints the proteoglycan, aggrecan, gives cartilage compressive resilience to permit weight bearing, but in disease aggrecan is degraded by ADAMTS enzymes. The challenges to the field are to determine which ADAMTS is involved, when these enzymes are active and precisely where they come from. We hypothesise that ADAMTS-4 and-or ADAMTS-5 is involved in cartilage pathology. To test this hypothesis we aim to [1] Generate mice containing mutant ADAMTS-4 and-or -5 in all cells, or [2] in car ....In healthy joints the proteoglycan, aggrecan, gives cartilage compressive resilience to permit weight bearing, but in disease aggrecan is degraded by ADAMTS enzymes. The challenges to the field are to determine which ADAMTS is involved, when these enzymes are active and precisely where they come from. We hypothesise that ADAMTS-4 and-or ADAMTS-5 is involved in cartilage pathology. To test this hypothesis we aim to [1] Generate mice containing mutant ADAMTS-4 and-or -5 in all cells, or [2] in cartilage cells only. [3] Analyse mutant mice for changes in skeletal architecture, changes in ADAMTS mRNA and protein, and changes in aggrecan breakdown products. [4] Assess disease severity in mutant mice in in vivo models of joint disease. We already have mice with ADAMTS-4, or -5, mutated in all tissues and we are generating the double mutants now. We will also generate single and double mutants with dysfunctional enzymes in cartilage only. We will examine skeletal structure by histology and X-ray at all ages and monitor for expression of ADAMTS-1 and -9 to detect any compensatory over-production of other potential 'aggrecanases'. We will also do co-culture experiments in which cartilage and synovial cells from combinations of mutant and control mice will be incubated together to determine whether synovial ADAMTS can penetrate and degrade aggrecan in cartilage. Finally we will induce arthritis in mutant and control mice and monitor them to detect differences in the time of disease onset, the rate of disease progression and overall disease severity. A comparison of whole-mouse with cartilage only mutants in the in vivo models will complement the in vitro co-culture studies and determine whether other joint tissues such as synovium and joint capsule can also produce ADAMTS enzymes that destroy cartilage. This is not known. Together these experiments will reveal if, where and when ADAMTS-4 and-or -5 are active, and whether indeed they are the best targets for drug development.Read moreRead less
Molecular Mechanisms Of Cartilage Degeneration In Osteoarthritis
Funder
National Health and Medical Research Council
Funding Amount
$457,517.00
Summary
Arthritis affects 15% of the entire Australian population and 50% in people over 60. The most common form of joint disease by far is osteoarthritis (OA). One of the central features of OA is the breakdown of the cartilage that covers the ends of bones in joints, and this is a major determinant of the long term outcome and need for joint replacement surgery. There are no current therapies that halt or reverse cartilage breakdown in OA. This is largely due to our incomplete understanding of the mo ....Arthritis affects 15% of the entire Australian population and 50% in people over 60. The most common form of joint disease by far is osteoarthritis (OA). One of the central features of OA is the breakdown of the cartilage that covers the ends of bones in joints, and this is a major determinant of the long term outcome and need for joint replacement surgery. There are no current therapies that halt or reverse cartilage breakdown in OA. This is largely due to our incomplete understanding of the molecular changes and pathways involved in both the onset and progression of cartilage breakdown. Powerful new genomic approaches allow simultaneous screening of changes in a broad profile of genes, particulalrly in humans and mice following complete sequencing of their genomes. By applying this new technology in the earliest stages of cartilage degeneration in OA, the role of novel genes and the pathways involved in the onset of this disease process can be discovered. However, to investigate changes at the initiation of disease, tissue from animal rather than human joints must be used due to the difficulty in obtaining pre-symptomatic human cartilage. In order to maximise the number of genes screened, cartilage from a novel surgically induced model of OA in mice will be used in this study. We have developed micro dissection and linear mRNA amplification methods to overcome inherent problems with tissue availability from this small animal species. Successful completion of these studies will for the first time allow identification of the complex changes that occur in early OA. An important and likely outcome of this research will be identification of novel matrix proteins and regulatory molecules that will provide critical information for the development of new diagnostic and therapeutic approaches to OA.Read moreRead less