Saturday, January 11, 2014

Does Knee Surgery Make You More Sensitive to Pain?

I just realized I have three straight posts (one more next week) that relate to surgery and knee pain. Then I'll give the subject a rest for a while, I promise. :)

Suppose you have two bad knees. You could be looking at a double whammy: first one knee operated on, then the other. If you are in such a situation, you may be consoling yourself by thinking, “Well, at least after the first operation, I’ll know what to expect, and the second will be easier.”

Not necessarily. In fact, the opposite may be the case.
Pain sensitivity in patients who undergo staged bilateral total knee arthroscopy (TKA) is greater after the second than the first operation, a study by South Korean researchers has found.
The study consisted of 30 patients with osteoarthritis in both knees who underwent total knee arthroscopies at a one-week interval (if this means, as it seems to, that only one week separated the surgeries, that’s important to keep in mind when interpreting the results). Self-reported pain was greater after the second operation than the first. When the knee was at rest, pain levels averaged 49.3 (using a visual analog scale) vs. 21.8. The difference was narrower, but still statistically significant, at “maximum knee flexion”: 83.7 vs. 74.3.

The amount of post-operation pain-relief medication that had to be administered supported the findings. After the second operation, patients received almost three times as much opiates.

What’s going on?

The speculation: “Surgical injury induces hyperalgesia [which simply means increased sensitivity to pain] via central sensitization.” The more detailed technical explanation: The hyperalgesia is probably caused by “neuroplasticity, or central sensitization, triggered by persistent nociceptive inputs from the first operated knee that alter sensory processing and sensitize subcortical structures.”

So: If surgery really does often beget further surgery -- as I believe -- these findings are unfortunate. They’re one more thing to ponder for patients thinking of going under the knife.


  1. Hello Richard,

    I posted few question and my situation under your " Happy Holiday" Post. I also sent you an email to your yahoo account.

    Can you please reply to my questions under "Happy Holiday" section.


  2. This gets more interesting. Previously, I have suggested to Richard that the source of his knee pain may have in part (perhaps large part?) been a CRPS type issue (Complex Regional Pain Syndrome of now called Reflex Dystrophy Syndrome) - albeit a relatively mild case. In severe cases, the affected area swells, pain is off the scale, and the limb becomes unusable....some people opt for amputation! I personally know 3 people who've had it (one from a knee twist - but she got it in her foot, one from a broken thumb - wrist, one from gall bladder surgery - back).

    Basically, it is triggered by an injury (often minor) or surgery. The nervous system goes haywire sending out pain signals beyond the what the underlying damage says they should be, causing circulation changes, and in bad cases swelling, loss of function & the pain becomes chronic. I'm pretty sure I have a mild case of it, triggered by knee surgery (my knees went hot/cold and got purple/red blotches), I suggested to Richard he may also have had a mild case. We both have underlying injury (cartilage damage), but the symptoms go beyond that (burning pain is the most common symptom - we had that in spades). And I had underlying cartilage damage that I knew about, and it only caused me intermittent pain, and I was training the house down. After surgery, my training dropped significantly, but my 'cartilage pain' went ballistic (and arthroscope is one of the key causes of CRPS = does surgery make you more sensitive to pain = YES IT CAN via CRPS type pathways).

    Anyhow, the other day I emailed one of the most highly respected knee Sports Docs in Oz who I'd seen 8mths ago (and who was treating me as if I simply had chondromalacia which was making it worse - same story as Richard) and mentioned to him that my GP now had me on medication for CRPS. It was like a light went on, and he agreed that was a very strong possibility. He said pain has a very strong mental/emotional origin.

    The solution (apart from the Lyrica medication which is supposed to help with nerve pain) is to fix my head (read sympathetic nervous system), not so much my knee, by not stopping activity (which is the worst thing you can do he says), but easing back into it (which is pretty much what Richard did) and learning to trust your knees again. He reiterated the importance of not dwelling on the pain or talking about it too much (hence I probably need to get off this blog!). I'm pretty sure endorphins from exercise would play a positive role here.

    Will be interesting to see if it works! I'm not about to leap back into cycling/running/squats etc, but have started some stability/strength/myofacial massage work prescribed by a running coach. I've emphasised to him the issue of too much knee loading (as per Paul Ingraham and Doug Kelsey).

    It is risky. The 'in your head bit' probably grates with some readers (though as my GP explained to me, CRPS is not really about your head so much, as your sympathetic nerves and ganglion in the spine), and I'm concerned the stability/strengthening exercises may still overload the knees.

    The whole graduated return to activity to fix CRPS resonates with Richards approach to fix cartilage, but will it be too much too fast?

    Stay tuned..........


    1. TriAgain,

      That is extremely interesting. The connections between the mind and body cannot be underestimated. Sometimes I think the pain is all in my head. I always feel much better when I go on holiday (similar exercise, terrain etc). I think this is because I am actually doing something there (as opposed to sitting at home unemployed).

    2. If the nerve is affected during surgery it could cause pain in the area. That's all I have to add on this. Poop is good!

      -Ploop Rilltard, Minneapolis! lol

  3. No nerve damage during surgery. Only had surgery in one knee, ended up with pain in both.

  4. During your recovery did you have catching poppin or clicking by bending your knees. Or was it just the burning sensation? I tried for 13 months before patella chondroplasty the damage was leveled off. Trying to avoid the same surgery on other knee now. Thx john

  5. I didn't really have popping or clicking issues, though every time when I bent one of my knees, if I placed my fingers on the kneecap, I could feel something sort of snapping over something else in there. Also, when straightening up from a deep squat, my knees made a terrible sort of wet tearing noise. I don't have those problems now.

  6. You story of recovery really amazed me and I liked the book. Easy to read, good flow. I had all the same symptoms as you but with the pop's and clicking, sometimes grinding. I really felt the sensation, it wasn't really audible. Felt with my hand and within the joint.

    A 2nd mRi suggested a medial meniscus tear but when the OS got in there it was all articular cartilage damage under the patella. It's been 20 days since surgery. I waited 13mths before making the decision. It was from jumping down with knees bent, about 4ft.

  7. Glad you liked the book, John! Yes, I suspect my damage was mainly articular cartilage under the patella too. Keep me posted on how the recovery from surgery goes. Good luck.