My Doctor Says I need a Knee Replacement

Osteoarthritis and Exercise
“My Doctor says I need a knee replacement, so I don’t think exercises will help me”

Words matter

From my 30 year experience treating people with pain and teaching them about the need to exercise, I know now more than ever “that words matter”. The narratives we provide to explain or describe certain phenomena can have lasting impacts on individuals’ beliefs about their condition, attitudes towards treatment, expectations for the future, and daily behavior [1]. The traditional model of thinking about Osteoarthritis is a purely mechanical one, describing “wear and tear” of knee cartilage and using vivid imagery of “bone on bone” pathology. This type of explanations make patients fearful of movement and this increases their pain!

There is no research that shows that replacing cartilage reduces pain

A recent qualitative study by Bunzli et al. surveyed patients on the waitlist for knee replacement, and found that all participants believed their knee was “bone on bone”, that it was caused by “wear and tear”, and that their knee was so “vulnerable” that further loading would cause significant damage to the joint [2].
A large portion of participants believed that physical therapy and exercise interventions would worsen their symptoms because they could not replace lost knee cartilage despite the ample scientific evidence discussed in our last newsletter regarding the benefits of exercise interventions.
Instead, participants opted for experimental treatments and surgical interventions that they believed would restore knee cartilage, thereby reducing pain – despite no evidence that such approaches provide any clinical benefit.

Exercises can reduce knee pain, but patients need more!

Even more frustrating, even when individuals with advanced osteoarthritis do engage in regular exercise and observe significant symptomatic and functional benefits, their thoughts often remain preoccupied with knee pain, knee damage, and the view that they need a knee replacement [3].

For these reasons (among many others), we encourage both clinicians and laypeople to be cautious with their language around pain-related conditions – in our view, there is no reason to ever use the descriptors “wear and tear”, “bone on bone”, or to talk about cartilage at all — but rather to emphasize the individual’s adaptability, to promote safer metaphors like “motion is lotion”, and to de-threaten the perception of exercise.

Imaging is only part of the story

Clinicians must explain that knee pain is a modifiable symptom related to sensitised knee structures and influenced by a variety of biopsychosocial factors, rather than solely related to damaged structures. This message is underpinned by knowledge that levels of pain and disability are often poorly explained by the degree of structural change on imaging; and that symptoms are influenced by a person’s individual context, including life stage, psychological, social, physical and lifestyle factors, and health comorbidities.

Early intervention

A recent study shows that people who underwent a partial meniscectomy are 300% more likely to get a knee replacement. Women were twice as likely to get a knee replacement [4] If we can help patients early on and avoid this first surgery, their chance of needing a TKA are greatly reduced. We need to educate our patients early on and give them the tools to build resilience.

So what do we know?

The degree of structural changes on Xray and MRI do nor correlate to the degree of pain.
Other factors affect the degree of pain
Exercise can reduce pain, especially aerobic exercises. Strength training can help with building resilience. Explain to the patient why movement and loading are helpful and needed.
Words matter. The Nocebo effect is real. Be careful how you explain pain. The biomedical explanation may cause more harm that good. Make the explanation specific to the patient’s situation.