Welcome to the Centre for Research Excellence in Total Joint Replacement - OPUS

  • Centre Manager
    Dale Baum

    Email: dmbaum@unimelb.edu.au
    Twitter: @unimelbOPUS
    Facebook: @OPUSunimelb

    T: +61 3 9231 2553
    +61 435 697 011

    Scroll down to Scholarships section or visit the page:

Research Overview


The Centre for Research Excellence for OPtimising oUtcomes, equity, cost effectiveness and patient Selection (OPUS) in Total Joint Replacement will transform the research and practice landscape of joint replacement surgery, and promote critically needed stewardship to optimise management for better outcomes and reduced costs for this high volume and expensive procedure.

OPUS draws together Australian and international experts in clinical care, health economics, outcomes modelling, and implementation research to address unprecedented demand for the procedure (100,000/yr and rising), burgeoning costs ($4.5 billion/yr) and unresolved dissatisfaction (up to 1 in 3 patients).

Our Vision

The answer to the dilemma of a rising demand for a high-volume, high cost procedure is to ensure that those most likely to respond to total joint replacement are provided with appropriate, expeditious, efficient, and safe care with minimal complications. For those with end-stage osteoarthritis, where surgery may not be safe or desirable, effective evidence based non-surgical alternatives are required.

Scope of the Problem

Osteoarthritis – A leading contributor to the Global Burden of Disease.

Half of all Australians over 65 years are affected by osteoarthritis (OA) of the knee and hip. OA, which is the largest contributor to the global burden of musculoskeletal (MSK) disorders, has the sharpest upward trajectory across the MSK conditions (58% increase in the next 2 decades). With musculoskeletal (21%) rivaling mental and behavioural (23%) disorders for the greatest proportion of years lost through disability, the Global Burden of Disease Study has identified the former as one of the top three priorities that require urgent policy responses.

Use of Total Joint Replacement as a Treatment to Osteoarthritis

Current guidelines recommend non-surgical interventions for the majority of people with OA. In a proportion, however, OA progresses to a point where these interventions are considered ineffective and total joint replacement (TJR) becomes the only option to improve their quality of life.

Key Issues Involving Total Joint Replacements

Although TJR has revolutionized the treatment of patients crippled by end-stage OA and has been referred to as the operation of the century there is growing concern related to cost, demand and dissatisfaction that compels a reassessment of how TJR should be best deployed.


TJR is a highly cost-effective procedure for treating end-stage OA. Alarming increases in incremental and total costs of this procedure as well as projected rises in disease burden have raised considerable concern about the sustainability of current practices. In the Australian private sector alone in 2013, the direct cost of total knee and hip TJR was $414 million and $522 million respectively. These represent a rise in cost of 20% and 25%, respectively from the previous year.

Unnecessary Surgery

It is also estimated that one quarter of TJRs are performed in inappropriate candidates at an average cost of $21k per procedure, suggesting that up to $284 million of healthcare expenditure may be attributed to overuse of TJR each year in Australia. Moreover, post-operative complications add a further 18% of direct hospital costs ($210 million) in the first 30 days following TJR. The total direct cost of joint replacement surgery (public and private) in Australia in 2013 approximated $1.5 billion dollars. If indirect costs are estimated to be twice the direct costs, then the combined cost (direct and indirect) of treating end-stage OA with TJR is almost $4.5 billion. This represents almost 10% of all hospital costs ($55.9 billion) in Australia for the same period.


In 2014, almost 100,000 Australians received TJRs, representing an increase of 45% in hip and 77% in knee procedures since the first year of complete national TJR data collection in 2003. The annual number of TJRs is expected to double by 2030. This is consistent with overseas trends where TJR is projected to rise between 300-600% in the United States by 2030.

Patient Dissatisfaction

This may reflect lack of alignment of patient perception and operator expectations. The costs are high and can be reduced. Approximately 15-30% of patients remain dissatisfied following TJR, even in the absence of acute complications such as infection. Recent research indicates that the majority of patients undergoing surgical interventions overestimate the expected benefit and underestimate the harm and it is this imbalance that leads to dissatisfaction levels as high as 49% in TJR recipients compared to 6% in those whose expectations have been met. Patients regard this as a ‘poor outcome’, which leads many to seek ongoing care including implant revision of the implant or non-surgical therapies. This dissatisfaction is estimated to cost Australia $405 million from non-beneficial surgery in 2014.

Our Approach

We will cover clinical processes (Professors Peter Choong, Jane Gunn, Peter O’Sullivan, Nicolas Taylor, Peter Kent, Associate Professor Anne Smith and Dr Trisha Peel), decision making (Professor Anthony Scott and Associate Professor Michelle Dowsey), mixed outcomes (Professor Michael Kattan and Dr Tim Spelman), economic modelling (Professors Philip Clarke and Nicolas Graves) and implementation science (Professor Jane Gunn and Associate Professor Anne Smith) for interpretation and generalisation of our findings. These specialty areas of the patient journey are further defined through four research streams and related objectives: 

Workplan 1

Prognostic factors and outcomes modelling: We will Validate our risk prediction tool (nomogram) to identify preoperatively those patients likely to benefit and not benefit from total joint replacement.

Workplan 2

Shared decision making: We will develop a framework that facilitates informed consent by clarifying, quantifying and aligning patients’ and surgeons’ aversion/acceptance of risk.

Workplan 3

Non-surgical therapies: We will explore the barriers, develop and optimise conditions for a novel evidence-based multi-dimensional non-surgical intervention as an alternative to total joint replacement.

Workplan 4

Hospital services coordinated care: We will develop a framework for a safe, efficient, cost-effective, enhanced recovery program after total joint replacement that leverages coordinated multidisciplinary care.

An overarching transfer theme across all four work plans will also promote effective transfer of research outcomes into health policy and/or practice

These streams will focus on appropriate patient selection, informed consent, multidimensional cognitive therapies, and enhanced recovery care programs, respectively. Patient-centric safety and quality data, augmented by robust economic analysis, will underpin policy decisions, drive practice change and improve cost-effective, efficient and safe joint replacement surgery. Drawing on the experience and expertise of this multidisciplinary Research Team, dissemination, translation and implementation will be achieved through engagement of a scientific advisory council, annual stakeholder workshops, practical tools to aid community and specialist practitioners, and health professional training.

Capacity building will be realized through funding PhD scholarships and post-doctoral fellowships in this priority area, developing mentorship pathways for the future leaders, informing and influencing surgeon training, and developing and delivering training materials for professional capacity building Australia-wide. OPUS will engage a national team of research collaborators by providing a coordination and integration hub that will target and leverage all levels of NHMRC, ARC and NGO investment in musculoskeletal research. Through its unique and highly innovative approaches, OPUS will have a significant global impact by informing iterations of existing and future models of osteoarthritis care.

Click here for an in-depth explanation of our Workplans

Centre Output

The Work of this Centre will lead to:

i) A critical mass of investigators from various disciplines at the leading edge of world research with the skills to develop tools, respond to changes in practice or unexpected consequences of orthopaedic care identified through our large databases and to ensure that novel global changes in practice are rapidly tested for their place in the Australian system.

ii) Initially a tool to identify likely responders from non-responders of TJR will be developed and translated to practice, assessing its performance in high and low volume practices in rural and city locations. Translated and validated, this tool will inform appropriate patient selection. This will lead to significant cost savings by avoiding unnecessary and inappropriate surgery.

iii) A patient and surgeon “risk inventory” to help patients and surgeons understand their aversion/acceptance of risk and through this to highlight miss-alignments of expectations thereby enhancing the informed consent process. A translated and validated feedback intervention for surgeons will inform evidence-based decision-making and has the potential to minimise inappropriate surgery.

iv) Ongoing review of new evidence-based treatment alternatives developed and assessed by our team or others for those patients unlikely to benefit from TJR. This will provide an alternative to the primary surgical procedure for this cohort of patients and will lead to significant reductions in healthcare costs.

v) New knowledge about the clinical and health economic benefits of a multimodal pathway of care, leading to the development of evidence-based guidelines for patient care following TJR. In addition, accelerated pathways may lead to significant reductions in healthcare costs through decreased length of stay and reduced post-operative complications.

vi) Expansion in the cadre of multidisciplinary OA researchers through the Centre with PhD, Master’s and post-doctoral scientists immersed in this leading Australian centre at the cutting edge of research in orthopaedics . This will create a wide network of future leaders to equip our health professionals and health systems with evidence-based solutions in this global health priority area.

vii) New knowledge will form the curriculum development for the Australian Orthopaedic Association (AOA) surgical training program. This Centre will also integrate with the National Orthopaedic Academic Departments to establish expert research sites for the AOA Surgeon-Scientist program. This will ensure that orthopaedic surgeons of the future practice TJR in a multidisciplinary environment, cognisant of and guided by the evidence for and against surgery.

Patient Journey

Prior Experience

Revolutionary studies and tools created by our team prior to the inception of OPUS 

St. Vincent’s Melbourne Arthroplasty Outcomes (SMART) Registry which is a unique Australian resource developed by Professor Peter Choong and Associate Professor Michelle Dowsey. It holds data pertaining to over 11,000 total joint replacement procedures undertaken in over 8,500 consecutive patients, growing by 800 procedures/year, and yielding an extensive range and depth of demographic, surgical, functional outcomes and quality of life data.

This research has highlighted the important influence of patient, surgical, non-surgical interventions and health services factors on patient outcomes and health economics

SMART IN ACTION: First to show that radiologic osteoarthritis severity correlated with pain after total joint replacement surgery, a study that the International Society of Osteoarthritis Research considered as one of the most important pieces of work in 2013.

Computer assisted (CAS) knee total joint replacement study: First RCT ever to show the correlation between accuracy of surgery and sustained patient outcomes and satisfaction, setting the scene for the adoption of CAS in Australia that has now translated into longer survival of prosthesis with this technique.

Mindfulness based cognitive therapy Approach: An international first trial and multidisciplinary collaboration between orthopaedic surgeons and psychiatrists that examines mindfulness in patients undergoing total joint replacement. This major piece of work has led to the development and use of the common sense model to examine the interrelationships between quality of life and clinical symptom severity in patients with end-stage osteoarthritis.

Clinical pathways in total joint replacement study: First RCT ever to demonstrate the efficacy of clinical pathways for shortening LOS, and has been cited in a Cochrane Review on clinical pathways and translated into practice pathways for total joint replacement across Australia and the world.

Direct hospital costs study: Only publication using Australian data to examine cost determinants of total joint replacement, informing our successful BUPA Foundation Grant, which underpins Workplan#4.

There are very few publications on costs of total joint replacement in Australia; Our group has published 3 journal papers.

OPUS Metrics

The following metrics highlight the depth of experience within our team (June 2016).

Cumulative Publications1,417
Cumulative Citations31,997
Cumulative Research Funding$121,600,000


The Centre for Research Excellence in Total Joint Replacement (OPUS) comprises of a variety of clinical, sociological and surgically related academic and industry personnel.

Chief Investigators

The following Chief Investigators are below in order from A to K.


Professor Peter Choong

The University of Melbourne



Professor Philip Clarke

The University of Melbourne



Professor Tony Scott

The University of Melbourne



Professor Peter O'Sullivan

Curtin University



Professor Jane Gunn

The University of Melbourne



Professor Nicholas Taylor

La Trobe University



Associate Professor Michelle Dowsey

The University of Melbourne



Dr Trisha Peel 

Monash University



Associate Professor Anne Smith

Curtin University



Dr Tim Spelman

The University of Melbourne


Associate Investigators

The following Associate Investigators are critical to the progress of our research.


Dr Darshini Ayton

Monash University



Associate Prof. Michael Barrington

The University of Melbourne

St Vincent's Hospital Australia



Professor Nicholas Graves

Queensland University of Technology



Dr Maria Inacio

The University of South Australia



Dr Ian Incoll

Australian Orthopedic Association



Professor Michael Kattan

Cleveland Clinc



Associate Professor Peter Kent

Curtain University



Emeritus Professor Stefan Lohmander

Lund University



Dr Kieran O’Sullivan

Aspetar Hospital



Professor Jasvinder Singh

University of Alabama


Advisory Committee

The following Advisory Committee members are critical to the translation of our research.


Ms. Bronwyn Pike

Board of Director's Chair

Western Health



Professor Stephen Duckett

Health Program Director

Grattan Institute



Associate Professor Patricia O'Rouke

CEO, St Vincent's Health (Public) Australia



Mr. Ian Incoll

President, Dean of Education

Australian Orthopedic Association



Associate Professor Andrew Briggs

BSc (Physio) Hons (Curtin), PhD (Melb), FACP

Curtin University



Dr. Linda Swan

Medibank Australia



Professor Richard de Steiger

Epworth Victor Smorgon Chair of Surgery

Epworth Hospital



Ms. Linda Martin

Move - Arthritis Foundation



Curtin University

The University of Melbourne

La Trobe University

Monash University

Queensland University of Technology

The University of South Australia

Lund University

St Vincent's Hospital Australia

Aspetar Hospital Qatar

Australian Orthopedic Assoc

Cleveland Clinic


NHMRC Centre for Research Excellence - APP1116325

Research Publications

Nil as yet


Issue 1, 1st of May, 2017

PhD Scholarships and Projects

NHMRC Centre for Research Excellence Scholarship (x2)

Department of Surgery, St Vincent’s Hospital, The University of Melbourne

Expressions of Interest

The University of Melbourne’s Chancellery division have awarded two scholarships to the Department of Surgery’s in recognition of their efforts in obtaining NHMRC funding for their Centre of Research Excellence for Total Joint Replacement, which has goals in OPtimising oUtcomes, equity, cost effectiveness and patient Selection (OPUS).

The funds are for the purpose of research into arthritis, with particular attention to the study of osteoarthritis or any other related theme in synergy with the programs 5 year focus spanning clinical care, health economics, outcomes modelling, and implementation research. Applicants with an undergraduate background in Medicine, Health Science, Physiotherapy, Nursing, Psychology, Statistics and Epidemiology will be looked up favourably.

Specific eligibility criteria are listed in the document here. Please see OPUS website for more information or contact the Centre Manager: dmbaum@unimelb.edu.au, (03) 9231 2553.


Title: Optimal Pain Assessment in Joint Replacement Patients​

Available: Yes

Partners: The University of Melbourne & the University of South Australia

Background: The lifetime risk of an Australian undergoing a knee or hip replacement is 10-12% and annually almost 100,000 joints are replaced in Australia, making it one of the most common elective surgical procedures in this country. Patients have joint replacement surgery because of severe arthritis that causes them debilitating pain and limited function. While this surgery should provide patients with substantial, if not complete, pain relief from their disease, post-surgical pain is common. Thirty eight percent of patients present to their general practitioners within 30 days post-surgery for assistance with pain management. Up to one third of patients report chronic post-operative pain and 19-42% still take opioids one year after surgery. Opioids are strong pain relief medications associated with significant side effects, including intoxication, dependency, and abuse, and limited evidence of their long term efficacy. Because of the accumulating evidence of the detrimental effects of opioid use and ineffectiveness for long term pain relief, understanding post-surgical use of opioids for pain relief and rehabilitation in joint replacement patients is needed. To determine the effect of opioids in the post-operative pain relief of joint replacement patients, this study will compare patient reported pain, function, and other patient assessments with their analgesic medication use, with great focus on opioid medication use. We will determine how opioid use is associated with patient reported pain, whether changes in pain are associated with changes in opioid use, and identify patient groups at a high risk for suboptimal opioid use. Our study’s findings will be useful to patients who have joint replacements and their providers, who struggle in balancing the risks and benefits of opioid therapy when recommending pain management treatment. The study will use a unique dataset, which is a dedicated clinical registry that includes high quality patient reported pain assessments for a group  of nationally representative joint replacement patients. Characterising the progression of pain after joint replacement and patients at risk of suboptimal opioid use will assist and aid clinicians in the identification of patients that will benefit from additional education and support for pain management as well as inform the development of opioid use protocols post-surgery.

Preferred prerequisite studies: epidemiology, phamacology or pharmacoepidemiology, orthopaedics/musculoskeletal disease.

Title: Using health-related quality of life scores as predictor of outcomes and to advance health economic evaluation methodologies in lower limb arthroplasty patients

Available: No

Partners: The University of Melbourne and St Vincent’s Hospital

This project aims to use the registry data to demonstrate that health-related quality of life (HRQL) scores can be used to independently predict outcomes such as mortality, need for revisions or surgery-related complications and to develop a risk assessment tool to assess outcomes in patients undergoing lower limb arthroplasty. These findings have the potential to add clinical value in informing the potential effectiveness and cost-effectiveness of the surgery in these patients.

Patients undergoing lower limb surgeries are generally older patients with considerable co-morbidities hence their competing risk of death and potential surgery-related complications can be high. Although surgeries such as total knee replacements (TKR) have proven to be cost-effective treatments for end-stage osteoarthritis, studies have shown that the cost of TKR can vary between patient subgroups; for example, TKR has been found to be more cost-effective in younger patients and those classified as low-risk based on age and co-morbidities. Measuring value and understanding the cost of services is imperative in healthcare where providers are challenged to balance between the provision of quality care and to cost contain.

The St. Vincent’s Melbourne Arthroplasty Outcomes Registry (SMART) is a clinical registry which collects both clinical and patient reported outcomes in patients who have undergone elective lower limb arthroplasty at St. Vincent’s Hospital. The registry has recorded information on patient demographics, arthroplasty details and death for these patients since 1998. From 2006, the collection of patient reported HRQL was initiated and patients were followed-up at regular time intervals. Patients’ hospitalisation and surgery costs will be extracted from routinely collected administrative data at St. Vincent’s Hospital.

Preferred prerequisite studies: Health economics

Title:  Improving physical activity post hip and knee arthroplasty

Available:  No

Partners:  La Trobe University and The University of Melbourne

Background:  Hip and knee replacement surgery is an appropriate intervention for severe osteoarthritis unresponsive to conservative management. However, studies have shown that physical activity levels of individuals who undergo hip and knee replacements fail to meet the World Health Organisation’s minimal physical activity recommendations. Consequently, physical activity levels remain reduced despite individuals experiencing a reduction in pain, improved physical functioning and an enhanced ability to mobilise.

Reduced physical activity is associated with higher incidences of health risk factors, ultimately resulting in higher all-cause mortality rates for people with hip and knee replacements, when compared to the average population. As the rates of hip and knee replacement surgery continue to increase, failure to address the issue of reduced physical activity leaves these people at greater risk of early mortality from otherwise preventable health conditions. Evidence from other fields of rehabilitation have shown that patients who participated in an appropriately structured rehabilitation program achieved long-term behavioural change in the area of increased physical activity levels.

This project will comprise of a number of research studies that progressively addresses the question. Firstly, a systematic review of literature identifying physical activity levels and physical function post hip or knee replacement will be conducted. Second, an observational study of physical activity levels and factors associated with those levels. Third, an intervention in the form of a randomised controlled trial. Fourth, a qualitative study on the perceptions of participants in the interventional study. The goal of these studies is to assist rehabilitation clinicians to identify a method of delivering rehabilitation post-lower limb arthroplasty that increases physical activity levels, and to inform post-surgical rehabilitation protocols in this patient population.

Preferred prerequisite studies: Physiotherapy, rehabilitation, physical activity, orthopaedics/musculoskeletal disease

Research Projects

This Research Group doesn't currently have any projects

Faculty Research Themes

Infection and Immunology, Child Health, Neuroscience, Cancer

School Research Themes

Child Health in Medicine, Neuroscience & Psychiatry, Cancer in Medicine

Key Contact

For further information about this research, please contact Email: dmbaum@unimelb.edu.au
Twitter: @unimelbOPUS
Facebook: @OPUSunimelb

Department / Centre

Surgery Research

Unit / Centre

Research Streams