Dispelling these common misconceptions can reduce harm, reassure patients and improve outcomes…

While the key pillars of managing hip and knee osteoarthritis are well understood, some persistent myths contribute to needless imaging, over-treatment, and undue patient concern, says consultant rheumatologist Professor David Hunter, Florence & Cope Chair of Rheumatology at the University of Sydney and lead of the osteoarthritis research team at the Kolling Institute of Medical Research.

Myth 1: Imaging is essential for diagnosis

Fact: Diagnosis can often be made clinically – and imaging may do more harm than good

“If you’ve got an older adult that presents with mechanical knee pain, and they’ve got features that are consistent with osteoarthritis, you can be pretty confident they’ve got osteoarthritis. You don’t necessarily need to get imaging done,” Professor Hunter says.

Moreover, imaging frequently identifies abnormalities that are simply features of OA.

“And that war zone of the report is pretty hard for a patient to unsee,” he says. “A meniscal tear is a universal part of osteoarthritis. To get it repaired is not going to help with your symptoms. But unfortunately, it drives up the rates of arthroscopy by about 10 times.”

Recent Australian research found people who were shown x-rays as part of knee OA diagnosis had a higher perceived need for joint replacement surgery than those who were diagnosed clinically without being shown X-rays. They also believed exercise and physical activity were more harmful, were more worried about their knee condition getting worse, and had more fear of movement.

Importantly, symptom severity and radiographic findings often correlate poorly. Some patients with significant radiographic change remain highly functional, while others with relatively modest changes experience substantial pain and disability.

Myth 2: Pain means patients should avoid exercise

Fact: Exercise is a mainstay of knee and hip OA management

Cochrane reviews of exercise for osteoarthritis of the knee and the hip have shown that it probably improves pain and physical function, although these effects may be small.

Associate Professor Michelle Hall, co-lead author of the just-released hip OA exercise review from the University of Sydney, says their findings suggest we “should be honest with patients that the average benefit may be modest.”

“We know people are generally worse off when they stop moving altogether. The message isn’t to avoid exercise. It’s that we need better evidence to determine which types of exercise work best for different people with hip osteoarthritis.”

Professor Hunter notes the recent Cochrane review found modest average improvements in pain and function (around 7 points on a 100-point scale), which may not reach a clinically important threshold.

“However, it does not support abandoning exercise; rather, expectations should be realistic, and programs should be individualised. The evidence does not yet establish one superior form of exercise.”

Patients should aim to find something they can stick to longer-term, and many activities can be beneficial, including walking, cycling, tai chi, yoga and aquatic exercise—which can be a good starting point, he says.

“You feel better in the water. You feel supported. The pain might be better.”

At the same time, patients should be doing strength training to work towards land-based exercises, which are better for improving functional capacity, he explains.

Stretching is also important, he adds, noting muscle imbalances can adversely affect biomechanics. “The common one we particularly see in older adults who may be sitting too long would be tight hamstrings, and that contributes to adverse knee loads.”

Exercises should be tailored for each patient, he stresses.

“Usually, at least in the first instance, we encourage people to talk to a physiotherapist about what type of exercise they should be doing. So if there are certain muscle groups that should be focused on. The physiotherapist gives them the prescription, and they can go off and hopefully do that themselves three to four days a week.”

Myth 3: Paracetamol is first-line medical therapy

Fact: NSAIDs are now considered first-line when safe and appropriate

“More recent evidence, particularly coming from systematic reviews, shows that paracetamol is probably not providing much, if any, relief for pain in people with knee or hip osteoarthritis,” Professor Hunter says.

In older adults, it can also have more adverse effects than previously thought, including increased potential for liver toxicity.

“So it’s no longer the first-line recommended analgesic in most guidelines around the world. Anti-inflammatories are.”

However, caution is required when prescribing NSAIDs in a population that often has comorbidities such as renal disease, peptic ulcers, and cardiovascular disease, he stresses.

Treatment should generally be reserved for flare-ups, he adds.

“Usually in most guidelines, we recommend if you are prescribing an oral anti-inflammatory, smallest dose, shortest duration possible.”

In knee OA, topical NSAIDs may be as effective as oral preparations, although you still need to be mindful of systemic absorption.

“It’s probably about 2% to 3% of what you might get from an oral anti-inflammatory. But for a person who’s got exquisite hypersensitivity—if they get bad asthma with insignificant doses of anti-inflammatory, for example—I don’t think it’s necessarily worth the risk.”

Patients need to use topical NSAIDs two to three times a day and rub them in well.

Myth 4: Opioids are a reasonable escalation strategy

Fact: Other options are preferable

About 20% of patients with OA are on opioids, Professor Hunter says.

“There is a lot of harm, very little benefit. So we really recommend strongly against that.”

For patients who cannot tolerate NSAIDs, duloxetine may be an option.

“It’s off label, so I’m not advocating you do that,” he stresses. “But the evidence is pretty strong to support duloxetine as an alternative to some of these other oral analgesics.”

“We’d usually start just with 30 milligrams at night, potentially bump it up to 60 depending upon tolerance, and potentially all the way up to 120 milligrams at night.”

If pain is still poorly controlled, he recommends looking for other contributors, such as sleep disturbance, mood issues or activities that trigger recurrent flares.

Patients who cannot rehabilitate successfully should be referred, he says.

Who should you refer patients to?

Surgery is rarely the next step—and arthroscopy has little to no role in routine OA management, Professor Hunter emphasises. He recommends ensuring patients have a good physiotherapist, then considering referral to a rheumatologist or sports physician, who can assess biomechanical factors and offer interventions like bracing, footwear modifications, orthotics and injections to support function and rehabilitation.

Myth 5: Injectables provide lasting symptomatic relief

Fact: Their effects are often short-lived

Corticosteroid injections typically ease symptoms for four to six weeks, Professor Hunter says.

“If a person’s got to walk down the aisle or go on a trip they’ve been dying to do, that can be quite meaningful. But oftentimes people want a longer duration of relief.”

Steroids also have an adverse effect on chondrocyte health, he notes.

“So repeat steroid injections can accelerate progression of the disease. It shortens the time to joint replacement, basically.”

Hyaluronic acid injections also have limited benefit, he says.

“The best current evidence would suggest they may provide a small but not statistically or clinically meaningful benefit over and above a saltwater injection at three and six months. So most guidelines at this point in time don’t advocate for the use of viscosupplements.”

Preparations containing both corticosteroid and hyaluronic acid, such as Cingal, are showing promise, he adds.

“That does appear to provide benefits both acutely, which is what the steroid would do, but also at that three-to-six-month mark. So it’s a little bit more durable.”

Importantly, injectables are adjunctive therapies, not a replacement for the pillars.

Professor Hunter typically uses them to ease symptoms so patients can engage more actively in rehabilitation.

What about platelet-rich plasma (PRP) injections?

“There’s no benefit to be gained here over and above a saltwater injection,” he says, citing a study that found no statistically significant difference in pain or MRI cartilage thickness loss at 12 months in 288 people with mild to moderate knee osteoarthritis randomised to receive either three PRP injections or saline placebos.

“These are costly interventions, all out of pocket. And guidelines recommend against the use of PRP, and at least at this point in time, recommend against stem cell injections as well.”

Myth 6: Surgery is inevitable

Fact: Many patients do well with conservative management

“Epidemiologically, 10% of people with osteoarthritis require a joint replacement at some point during their osteoarthritis life,” Professor Hunter says.

“Even for people that were put on a waitlist for surgery, if they’re given appropriate treatment to help them with their strength and function, oftentimes they do really well, and, at least in the well-done trials, about two-thirds of people at three years still don’t want surgery.”

That said, “it can make a massive difference for those that do need it,” he emphasises.

This includes people with pain that continues to impact their functional ability, sleep or quality of life after exhausting conservative management options.

When referral is appropriate, Professor Hunter advises directing patients to specialist arthroplasty surgeons who do a lot of hip and knee replacements.