Do I Need a Knee Replacement? What to Try First

Physio · 8 minute read

If you have been told your knee is bone on bone, a replacement can start to feel like the only road left. For most people it is not the first step, and knowing what comes before it takes a lot of the fear out of the diagnosis.

What “bone on bone” actually tells you

An X-ray of an arthritic knee shows the space between the bones getting narrower. People often hear that described as bone on bone, and it sounds final.

It is a picture of the joint, not a measure of how much it hurts or how well you can move. A review of the research found that X-ray findings and knee pain often do not line up. Some people with worrying-looking X-rays have little pain, and some with mild changes have a lot. The authors concluded that knee X-rays should not be used on their own to judge a person’s knee.

Australia’s clinical care standard for knee osteoarthritis goes further. It says the diagnosis can usually be made from your symptoms and an examination, and that imaging is not routinely needed to diagnose it at all.

What the guidelines say to try first

The Australian Commission on Safety and Quality in Health Care sets out the care a person with knee osteoarthritis should receive in its Osteoarthritis of the Knee Clinical Care Standard (2024). The Royal Australian College of General Practitioners guideline for knee and hip osteoarthritis points the same way. Before surgery, they put:

1. 1Understanding what is going onLearning what osteoarthritis is, what makes it flare and how to manage it is a core part of care in the standard, not an optional extra.
2. 2Staying active and exercisingThe standard says being active can help manage knee pain and improve function. The RACGP guideline strongly recommends exercise for knee osteoarthritis, including walking and strengthening the muscles around the knee.
3. 3Support with weight, if it applies to youThe standard says people should be told how body weight affects their symptoms and offered support to manage it, in a way that suits their own priorities.
4. 4Using pain medicines carefullyMedicines can help some people. The standard advises that opioids should not be offered for knee osteoarthritis, because the risk of harm outweighs the benefit. Your GP can talk through what suits you.
5. 5Regular reviewChecking in on how things are going, and adjusting the plan, is part of the standard too.

One thing the standard specifically does not recommend: arthroscopy, sometimes called a knee clean-out. It says arthroscopic procedures should not be offered to treat uncomplicated knee osteoarthritis.

What happens to people who try exercise first?

The clearest answer comes from a Danish trial published in the New England Journal of Medicine. It took 100 people with moderate to severe knee osteoarthritis who were all eligible for a knee replacement, and split them into two groups by chance.

One group had the replacement followed by rehabilitation. The other had twelve weeks of non-surgical care instead: supervised exercise, education, dietary advice, insoles and pain medication, delivered by physiotherapists and dietitians.

In the non-surgical group, 26% had gone on to have the operation by one year and 32% by two years. Put the other way, two in three people who were eligible for surgery were still going without it two years later.

It is worth being honest about the rest of the result, because it helps with the decision. On average, the people who had the replacement improved more. They also had more serious complications in the first year: 24 serious adverse events in the surgery group, compared with 6 in the non-surgical group. Both paths helped. Surgery gave bigger gains for the people who went on to need it, with more risk, and the non-surgical path let most people put surgery off.

Australian data points the same way. In GLA:D Australia’s national results, about 1 in 2 people who wanted a joint replacement when they started the GLA:D program no longer wanted one, and had not had one, a year later. Those results have no comparison group, so they show what typically happened rather than what will happen for you.

When is a knee replacement the right call?

The clinical care standard is clear on this. A person whose symptoms keep getting worse, and whose daily life is severely limited even after good non-surgical care, should be referred on for further assessment, such as with an orthopaedic surgeon.

In plain terms, surgery is worth talking about when the knee keeps getting worse and is seriously restricting what you can do, even though you have given exercise and the other first steps a proper go. At that point your GP can refer you to an orthopaedic surgeon, and a knee replacement is a sensible option to discuss.

If you do go on to have surgery, the work you put in beforehand is not wasted. GLA:D Australia notes that people who complete the program before a joint replacement tend to recover faster afterwards.

A plan you can start this week

1. 1Keep walkingWalking is one of the exercises the guidelines recommend for knee osteoarthritis. Start with what is comfortable and build slowly. Our guide on walking with knee and hip arthritis covers how much, which shoes, and what soreness is normal.
2. 2Practise standing up from a chairSit on a firm chair and stand up without using your hands, then sit back down slowly. Do as many as feel comfortable, a few times a day. It builds the muscles that support the knee, and it is one of the tests physios use to track progress.
3. 3Use the 24-hour ruleA little discomfort during or after exercise that settles within 24 hours is normal when you start exercising. If it is worse the next day, do a bit less next time rather than stopping altogether.
4. 4Talk to your GPAbout pain relief that suits you, support with weight if it applies, and whether a GP Chronic Condition Management Plan makes sense. Our guide to using a care plan for physio explains how Medicare can help.
5. 5Get a structured programExercise works best when it is set at the right level and progressed. That is what a physio-led program like GLA:D is for.

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