Researchers at Monash University and La Trobe University have shown that exercise and education programs for managing knee osteoarthritis (OA) can be cost-effective for nine years by delaying the need for total knee replacement.

The study, which was published recently in JAMA Network Open (here), suggests that a national structured education and exercise therapy program may deliver substantial cost savings and that greater efficiencies may be gained through targeting specific patient subgroups (Docking et al 2024).

OA places a considerable burden on the Australian healthcare system, affecting 2.1 million Australians (ABS 2022) and costing $4.3 billion annually (AIHW 2023).

It is estimated that fifty-nine per cent of people with OA have knee OA (Ackerman 2023) and guidelines for best-practice management of knee OA in Australia—the newly updated Osteoarthritis of the Knee Clinical Care Standard (ACSQHC 2024)—recommend that people with knee OA undertake non-surgical management options including education, exercise and weight management before considering total knee replacement (TKR).

However, people presenting to their GP with knee OA are three times more likely to be referred to a surgeon than to a physiotherapist and many of these TKR surgeries may be regarded as inappropriate.

‘There is some Australian data that suggests that for about one in three Australians who have a knee replacement, the surgery is unwarranted because they don’t have severe enough symptoms and/or severe enough joint deterioration.

Dr Sean Docking

'And they also might not have trialled any nonsurgical management before having a joint replacement,’ says Dr Sean Docking, a health economist from the School of Public Health and Preventive Medicine at Monash University and lead author on the study.

Sean says the study aimed to understand what the lifetime costs and health outcomes would be if a national structured education and exercise therapy program was implemented to delay or avoid TKR.

‘To do this, we built a health economic model and used high quality Australian data on both the costs and the outcomes related to total knee replacement from the Australian Orthopaedic Association National Joint Replacement Registry.

We also used the outcomes from the GLA:D Australia registry for non-surgical management and the rate of total knee replacement following non-surgical management from randomised controlled trials,’ says Sean.

‘Using our model, we can estimate and compare the lifetime costs and outcomes if everyone has a total knee replacement or if they go into a non-surgical management program with the option for a total knee replacement later.

'What we found was that the healthcare system could save $100 million each year by avoiding or delaying unwarranted total knee replacements.’

It’s a substantial saving—current estimates suggest that the annual cost of knee replacements is around $1.5 billion in Australia (Docking et al 2024).

And while programs like GLA:D were not found to be cost-effective over a lifetime, the study determined that across the whole cohort, they were cost-effective for the first nine years.

In people with lower baseline levels of pain, the programs were estimated to be cost-effective over their lifetime.

‘That was an interesting finding but when we thought about it, it made sense.

'Both knee replacement and non-surgical management—and access to healthcare funding in each case—are critical to providing high quality, efficient care for osteoarthritis; it’s not one or the other,’ Sean says.

Professor Ilana Ackerman

Senior author Professor Ilana Ackerman APAM, also from Monash University, says that while it can be highly effective, TKR surgery should not be considered the first-line treatment for knee OA.

‘If you look at any of the clinical care guidelines from around the world, there are other interventions that should be tried first as non-surgical management.

'Once a patient has tried everything else and their symptoms are no longer responsive to those treatments or they have severe pain and functional impairment, then that is an appropriate time to consider going down the joint replacement path,’ Ilana says.

In addition, around 20 per cent of people who have TKR surgery may have persistent pain or be dissatisfied with the outcome.

While the tendency for GPs to send people to surgeons instead of physiotherapists is one factor affecting the number of people choosing surgery over non-surgical management of their knee OA, another factor is the perceived out-of-pocket cost to the patient.

‘They have to pay money to go and see the physiotherapist to get an exercise program and pay for the program.

Associate Professor Christian Barton

'While they might have to wait a while in the public system—or they might have private health insurance to cover it—it will sometimes be cheaper for them out of pocket to see the surgeon and have a $20,000 to $30,000 procedure and then get the physiotherapy afterwards for free,’ says La Trobe University’s Associate Professor Christian Barton APAM, another researcher involved in the study and a program lead for the GLA:D program in Australia.

In contrast, Christian says, the GLA:D program costs around $1000 and is starting to be covered by private health insurance.

A Danish program introduced in Australia in 2018 and now widely available across the country, GLA:D is typically a six-to-eight-week program comprising physiotherapy evaluation, two education sessions and 12 supervised exercise sessions, providing the patient with the tools to self-manage their OA.

While Sean’s model is a hypothetical view of a complex clinical scenario with key assumptions made, it suggests that identifying the patients who will most benefit from an exercise and education program like GLA:D rather than undergoing TKR is the next challenge.

‘We have an opportunity to deliver these cost savings if we correctly identify the right people; how we do that is the unknown at this stage.

'There are a few tools out there but they haven’t been tested from a cost-effectiveness perspective,’ says Sean.

One possibility will be to use the data collected by the GLA:D registries in both Australia and Denmark to follow the progress of patients from enrolling in the GLA:D program to having TKR surgery.

‘Starting with the 2018 cohort, we’re going to check in to see how they are doing—if they’ve had surgery, what their quality of life is like and what they’ve gone on to do—so we can get that longer term evaluation,’ Christian says.

Christian and Ilana are also investigators on a Medical Research Future Fund grant project that aims to provide patients on public hospital waiting lists for TKR surgery with access to GLA:D and other first-line management in the community to see if that influences the number of patients who end up having surgery.

Ultimately, says Sean, the data generated by this study and others will help get the word out to GPs and other clinicians, policymakers, health insurance providers and governments that non-surgical management of knee OA is cost-effective and can delay or even prevent unnecessary TKR surgery.

With the number of Australians with OA predicted to rise to more than three million by 2040, it’s critical that all patients have access to optimal care while reducing the burden on the healthcare system.

‘We’ve got massive waiting lists for total knee replacements in the public health system—if we improve first-line management or make the non-surgical management options more easily accessible, we can actually alleviate pressures on the hospital setting.’

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Rescuing the older knee