Total Knee Arthroplasty – Who Struggles?

5 min read. Posted in Knee
Written by Eric Bowman info

Over the last decade, a lot of orthopedic surgeries have gotten somewhat of a “bashing in the literature.” If you’re not familiar with the lack of support for some surgeries I recommend reading this blog by Todd Hargrove on the topic.

One surgery that, until more recently, has escaped the negative press is the Total Knee Arthroplasty (TKA) – also known as Total Knee Replacement (TKR). TKAs are one of the top conditions I’ve treated people for in my career and I’ve seen many clients do well and the research is generally supportive of them.

That said – the ones that struggle, really struggle. Up to 30% of clients after TKA (1) are not getting a significant improvement from it – which is A LOT for a surgery that is done very commonly and has a high cost on the healthcare system.

In this blog I discuss:

  1. Who tends to struggle with TKAs?
  2. Preventative options for poor outcomes.

Even though this is written about TKAs, I do believe that these can be applied to many other surgeries and to other areas of chronic musculoskeletal pain in general (2).

Before we get into the meat and potatoes – it’s also important to understand that many people having or requiring TKAs may have other comorbidities to take into account. I recommend checking out this masterclass on Exercise Prescription For Aging Adults for more information.


Part 1: Who tends to struggle with TKAs?

The biggest predictors of those who are likely to struggle following a TKA, are the following:

  1. Obesity – A large body of research has shown the link between obesity, knee osteoarthritis (OA) and poor outcome with TKA (3, 4). Whether this is due to increased strain on the joint, inflammation (5), or overall poor health and deconditioning, is yet to be determined.
  2. Smoking – Smoking affects blood flow, contributes to inflammation and affects cardiorespiratory function so it’s not hard to see why smoking is a risk factor for poor outcomes (4) and can be a “make or break” between someone opting for surgery or not.
  3. Psychosocial factors – Unless you’ve been under a rock or haven’t opened a research paper on musculoskeletal pain in the last 10 years, you’ve likely heard about the link between psychosocial factors and pain and this applies to TKAs (6).


  4. Disconnect between radiographic OA and symptoms – Radiographic OA refers to the amount of arthritis and joint degeneration shown on an x-ray or MRI. Interestingly, finding very little on X-ray is a predictor of poor outcome with TKA (7). When you think about it too – it makes sense. The premise of orthopedic surgery is to fix the tissue fault that is causing the problem. If the client has a lot of pain but has minimal tissue changes it reasons to stand that there are other contributors to the clients’ pain.


Part 2: How can we prevent poor outcomes after TKA?

This really comes down to a two pronged approach:

  1. Communicating with the client’s family doctor and surgeon (where applicable), on your:
    1. Understanding of the client’s situation
    2. Concerns with having surgery. During my last job, when working in collaboration with many orthopedic surgeons, this could make the difference between a client having surgery or not.
    3. Discussing next steps: I sometimes hear from clients that surgeons say “surgery won’t help you and there’s nothing we can do for you.” Whether that is what the surgeon actually says, or what the client interprets, is a discussion for another time – but there are almost always options to move things forward and to help reduce suffering if the client is willing to do so.
  2. Working on potential prognostic factors including:
    1. Body weight: working with dietary professionals to help with reducing bodyweight and inflammation and through encouraging exercising of non-painful areas which has some evidence for chronic pain (8).
    2. Smoking cessation: depending on your jurisdiction this may be out of your scope of practice and again may require referrals to other professionals
    3. Mental health referrals to address psychosocial factors
    4. Appropriate rehab program


Side note: while the research is conflicting on whether prehab is effective compared to no prehab post TKA (9) anecdotally I do believe prehab makes recovery quicker. I also believe, that it’s more about having a higher level of fitness and mobility heading into the surgery than anything else.

Working on the above can be very overwhelming for a client at once. Don’t be afraid to, in a “block periodized” style of rehab, to prioritize different things at different times. In Canada where I work, there can be a huge wait time for surgeries. These can be seen as a blessing in disguise to provide a window to address these other factors.

Another essential component with these clients is goal setting and expectation setting (10). I hate when clients go into surgery expecting it to be the “cure all” when at best there may be a small to moderate improvement. This can be extremely disheartening for the client and can make them feel defeated. It is critical for orthopedic surgeons, family physicians, and rehab professionals to be very transparent with clients about the expected outcome. If a loved one of yours was having surgery, wouldn’t you want them to know what the expected outcome would be?


Wrapping up

As time goes ahead it is likely that a greater effort will be made to steer people away from orthopedic surgery although many surgeries will still happen especially as society ages. There are still plenty of good reasons for some orthopedic surgeries; as a physio can’t reattach a shattered ankle or a busted femur; but there needs to be greater consideration to proper preparation and selection of surgical clients. I recommend checking out this masterclass on Exercise Prescription For Aging Adults for more information.

As always, thanks for reading!

Want to learn how to optimise your exercise prescription for older adults?

Dr Mariana Wingood has done a Masterclass lecture series for us on:

“Exercise prescription for aging adults”

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If you have a question, suggestion or a link to some related research, share below!

  • Jonathan Khoo

    yes this is very good . Its important to give advice re; weight loss, smoking, diet, prehab and education of what happens during and after surgery to make the patient have the best educated decision on surgery.

    Jonathan Khoo | 31 January 2023 | Likes

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