Evidence based medical wellness for active people from a doc who walks the walk

How not to wear out a knee replacement


Now that I am a proud owner (?wearer) of a smith and nephew knee replacement, I thought I should figure out what exactly I can do with it.  I told my doctor before hand that I wouldn’t have a knee replacement just to sit on the couch. I wanted to continue tennis, skiing and hiking. I would give up running, however.

Now that I have the new knee, I am not anxious to go through all of this again.  I don’t want to have to replace it again. So how exactly do you wear out a knee replacement? There are a couple of ways that you do can do it. First off, you can wear through the plastic “fake meniscus”.  This part can usually be replaced.  The more serious way to wear it out is from constant friction, such that the implants rub on each other and the friction creates small particles from the implants.  The body recognizes these particles as foreign, and attempts to digest them, which then may cause bone loss beneath the implant.  This leads to loosening of the prosthesis, and ultimately, the entire replacement has to be replaced.  This is called “aseptic loosening” and is the most common cause of knee implant failure.


So how do you prevent your knee joint from wearing out?!!! Good question, with no good answer! There are some things that help though:

Good body mechanics. As my physical therapists are always yelling/telling me: bend your knees, get your butt back and use your butt muscles instead of your quads to move.  Good advice, but a whole new way of moving. I spent many years as a competitive ice dancer, where upright posture was everything! I am trying to unlearn my upright posture and get my butt out.

Avoid high impact.  I get it, I get it, I get it.  I don’t run anymore, but am unwilling to give up tennis.  In my heart of hearts I would love complete a sprint length triathlon just to say I could,

There have been some studies that looked at statins (cholesterol lowering drugs) and osteoporosis drugs (bisphosphonates) in animal models.  However no human trials exist. So since, we aren’t rats or dogs, it is hard to say if these drugs will help.  I could see myself taking a statin if needed.

So, I guess the one things is : follow your physical therapists advice!

Picture of tools used in knee placement

Here are all the tools the orthopedic surgeon uses when doing a knee replacement. I hope the beer can wasn’t in the operating room!  Do you see it in the upper right corner? It’s a Coors can, ’cause we are in Colorado!

BTW: for those that are interested, I have gone to REVO physiotherapy for 3 years. It is a “direct pay” physical therapy center (they don’t take insurance, but you can turn in your bills to your insurance company, or take it out of your HSA.)  I swear by these guys as they have got me through three surgeries, put up with my whining, and got me back to skiing this year, and tennis season too.  Thanks to my favorite physical therapists Brian Briggs, Dane DeLozier and Mathew Smith, for hanging in there with me!

Author: PookieMD

I am a board certified internal medicine physician. I love medicine and seek to bring evidence based medicine to the fitness and wellness world.

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