Saturday, November 23, 2013

Failed Treatments for Knee Pain, Electricity Edition

TENS (transcutaneous electrical nerve stimulation) is a process whereby a device produces a mild electric current to stimulate nerves to block pain signals.

Does it work for knees with osteoarthritis?

Apparently not.

That’s according to a U.K. study of 224 osteoarthritis patients who were 61 years old on average.

They were split into three groups, all of which received education and physical therapy. One group also got TENS treatments, another got sham TENS therapy (the device looked authentic but produced no electrical current), and the rest got nothing additional, beyond the education and exercise.

If the first group had improved the most, that would be evidence that TENS is effective. If the first and second groups improved more than the third, that would suggest that TENS doesn’t work, but there’s an associated placebo-type effect that does.

Instead we got option three: all three groups were found to have improved the same amount after six weeks, then 24 weeks.  (Their levels of pain, stiffness and joint function were assessed; presumably they all benefited from the education and exercise.)

So don’t expect to get pain relief by having someone zap you around your ailing knee.

Of course my new standard disclaimer applies here (in anticipation of the inevitable person who will protest, “But TENS helps me with MY knee pain”).

While this study shows no positive benefit, your mileage may vary. If TENS makes your knees feel better, and the treatment isn’t doing any harm, you might as well keep getting it.


  1. I've just had an MRI done of my knees and, unsurprisingly, there is nothing apparently wrong.

    1. Yup. Very typical. It's surprising how many people there are with knee pain who have "normal knees." I was told the same myself. Clearly, there is something wrong, and hopefully someday, doctors will be able to better diagnose what's wrong when nothing appears to be wrong.

    2. Thanks for that, Richard.

      Do you know any tests which can reliably diagnose PFPS (assuming that it exists!:

      I've heard that bone scans may be a promising option: (search in the document for 'bone scan').

    3. I'm dubious that there is such a thing as patellofemoral pain syndrome:

      I think you're better off trying to find out what's causing your knee pain -- or, if various tests (MRI, X-ray) show no obvious cause for the pain, you could try an "envelope of function" (search for it on this blog) approach to getting better.

  2. Much respect to Richard and his quest(ion)ing in the cartilage paradigm. My 2 cents here on TENS units.

    In my quest to heal my own knees ( a crappy surgery and OA), I started, post surgical failure, with Richards assumption that bad knees can heal and followed a few of R.B.'s basic premises, particularly that irritating cartilage in PT is no good. I also followed Richards advice, that no two sets of knees are alike and so struck out to make my own discoveries, in the effort to SAVE MY OWN KNEES. Over a year later the knees are much improved and still improving.

    All that said, I had success using a TENS unit to stimulate atrophied muscles, more specifically my vastus lateralus, which had become inhibited due to post surgical damage to my patella and hobbled by a lateral release.

    My point is, maybe a TENS unit isn't indicated for the direct relief of pain associated with arthritic conditions, but maybe it can be a useful tool in certain situations, like in restarting inhibited and non-firing muscles, which in turn could lead to experiencing less pain in the long run. Like the mantra here so often goes, healing cartilage takes forward thinking, innovation in the paradigm and a lot of patience.

    Good luck to everyone healing their knees. R-X

    1. That's a good point, R-X. There may be another useful application for TENS, other than pain relief. I knew someone would jump in, in defense of TENS, if I waited for a while. :) Which makes me curious: Anyone else out there have any kind of success with TENS, pain relief or otherwise?

  3. Did you get an MRI scan? Did it indicate anything?

  4. I don't have a success story. I am surprised that my knees seem in some ways better than they did after I initially suffered my injury. I don't think they're improving though. I have never gotten an official diagnoses...My GP thought I was faking it and "You can walk...there is nothing wrong". ...maybe, I should sue him...hahaha...anyways, first ortho thought it was patella tendon pain (my symptoms are from extended kneeling on hard surfaces...). Thought that 70% of pain would be gone in 3's been 14 months! Lol. ...Second ortho thought it was due to a foot injury I had and the knee pain/swelling...he said "I can make up some diagnosis if you would like". I'm not trying to be skeptical. This stuff actually happened. After that I got a bunch of rheumatological tests...all which came back negative. I showed the Rhuemmy (as they seem to be called...) my knee swelling and he said well "that's residual". He diagnosed me as having "Psoriatic arthritis" ...a random type of arthritis that comes and goes. They all ignored the fact that I had kneeled on hard surfaces for extended periods of times... babies...under 2 years...don't have knee-caps...that is why they can crawl without consequences...and most people are fine...but I have bony knees. Anyways, you can see they all had different diagnosis. After that I went to a second GP, she noted my problem and I asked for an MRI. I got it, it came back negative. Oh my god, I'm crazy right? ...anyways it has been a long road, I have researched near everything, seems I have something like hoffa fat pad inflammation, plica syndrome, scar tissue. Makes sense. That's why it's idiotic to kneel for extended periods without knee pads. ...I will be seeing my I guess 3rd ortho for this...he's been treating my foot issues...that's finally healing some...I can light log but there is sharp pain behind the patella...I think the scar tissue has ate into the (articular) cartilage ...a lot of people report that and it makes sense. We'll see..hopefully I'll recover...I'm 25...have been taking Animal Pak Flex...a joint supplement that contains glucosamine, chondrotiin, fish oil, curcemin, other stuff. It doesn't fix my problem ...BTW, just by looking at my knees it's pretty apparent they are swollen abnormally...anyways, the APF doesn't definitively help but it also probably doesn't hurt. I take it because I need to walk to do daily tasks. ...hopefully I will get the scar tissue/etc arthroscopically removed and be fine...the other possibility is articular cartilage damage...I am thinking to far ahead but I will ask for no microfracture and see if Richard's method works...if it continues to bother me or I have too many problems I will try PRP, stem cells, intra-articular HGH or prolotherapy. If I ever get microfracture or ACI or something (Hope to god not!) I will hopefully have the money to do PRP/SC's/HGH as an adjunct. ...there are some studies in Louisiana (Broyles) and Chicago (Cole) that I have been checking out...they basically do microfracture with all that regenerative crap which amplifies the repair ability. the meantime I am working a desk job and hope all these ailments don't keep me from working that case, I would have to do Medicaid or something ...and they don't cover most procedures I don't think. It's been real hard but I have no choice. If I am to attain any of my goals (hopefully a lot...) I want to get back to near-100%. Thanks for this site Rich, helps a lot. Glad your knees are doing so well. -Jeff from Chicago

    1. Jeff, is you pain just a sharp pain behind the kneecap in a very particular spot, or do you also have general aching and burning all over the kneecap? Do your knees change temperature a lot, do they change colour (purple, red blotches)?

      If they do any of these things, you should get checked out for CRPS (which it turns out was my main problem, on top of some articular cartilage damage).