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Thread: DEXA for curve monitoring

  1. #1
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    DEXA for curve monitoring

    On the current trial I am working on, we take whole body DEXA measurements in order to get fat mass versus non-fat mass (lean mass). It also gives a full version of the skeleton. I hadn't thought about it until yesterday as we were scanning someone, "Hmmm, I wonder if this would work for scoliosis?"

    Dual Energy X-ray Absorptiometry (DEXA) is what people get when they have their bone density measured. It's a lying down procedure (so that is one issue). But the amount of radiation is about 1/100 (or less) that of a chest x-ray. The radiation is equal to one day of background radiation while being on the planet earth. So basically, nothing. They don't even require the technicians to wear those radiation badges.

    I've seen studies that seem to say that a prone/supine scan is about 10 less than a standing x-ray. I'm sure it is variable though based on the stiffness and progression (??). But I was wondering if anybody here had come across any other studies that really looked at the difference of standing versus lying measurements. Or anything done with a DEXA. Or anything done to try and pseudo-load the spine while in the supine position. You all frequently are much more current on some areas of the literature than I am. Or at least more familiar with what has been published.

    I can see a ton of advantages to using a DEXA instead of an x-ray, although certainly there isn't the resolution that an x-ray has. It would primarily just be for curve monitoring.

  2. #2
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    Hi Kevin...

    We thought about it, as it would be a huge population to study. Unfortunately, we think that there's not a direct correlation between curve degree while standing and curve degree while lying supine. (In other words, one person with a 20 degree supine curve might actually have a 30 degree curve, while the next one might have a 50 degree curve. Or, someone with no curve while lying supine may actually have a significant curve while standing.) I'm guessing that it's based on how much flexibility and rotation each individual has.

    If you find out differently, I'll be anxious to hear about it.

    Regards,
    Linda

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    This is a bit left of the topic, but whenever I exercise, both in standing and prone positions, I wonder if working the muscles in the prone position, when curvature is less, could possibly work towards better stabilization.

    I know this is veering off in a different direction but, Kevin, I knew you would be reading this thread having started it, and I liked the fact that I have your attention

    Amy
    Amy
    58 yrs old, diagnosed at 31, never braced
    Measured T-64, L-65 in 2009
    Measured T-57, L-56 in 2010, different doc
    2 lumbar levels spondylolisthesis
    Exercising to correct

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    Quote Originally Posted by LindaRacine View Post
    Hi Kevin...

    We thought about it, as it would be a huge population to study. Unfortunately, we think that there's not a direct correlation between curve degree while standing and curve degree while lying supine. (In other words, one person with a 20 degree supine curve might actually have a 30 degree curve, while the next one might have a 50 degree curve. Or, someone with no curve while lying supine may actually have a significant curve while standing.) I'm guessing that it's based on how much flexibility and rotation each individual has.

    If you find out differently, I'll be anxious to hear about it.

    Regards,
    Linda
    Yeah, I would imagine that would be the case. There is a study in 2006 that used an axial loading device to compare standing versus supine MRI. The axial loading device recreated the results from the standing x-ray fairly consistently.

    I also wonder what progression would look like on a non-loaded scan. Would it suggest a different progression risk or outcome if a curve measured 25 while lying and 45 while standing versus 25 lying and only 35 standing? Hmm....

    Do you all have a research DEXA?

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    Quote Originally Posted by foofer View Post
    This is a bit left of the topic, but whenever I exercise, both in standing and prone positions, I wonder if working the muscles in the prone position, when curvature is less, could possibly work towards better stabilization.

    I know this is veering off in a different direction but, Kevin, I knew you would be reading this thread having started it, and I liked the fact that I have your attention

    Amy
    When we were discussing how to apply resistance in our home therapy portion of the study I suggested lying supine and legs straight (or bent) in the air. Then rotate left, then right, etc... This would ensure a trunk rotation and would basically be impossible to cheat. Or at least very difficult. We decided against it because of what you suggested, i.e. that the muscles would work differently in the lying down position so they might not be as effective. However, as you mentioned, perhaps it would also add something.

    I do these exercises during some of the yoga I do. This portion of the ab workout is brutal. You really have to stabilize your pelvis and fire every abdominal muscle you have in order to control your movement. Bending the knees helps reduce the resistance. But it's a great rotational/ab exercise.

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    Thanks for the speedy reply!

    I was thinking also of planks and all the variations of that exercise. They are so hard for me to do I want to cry, but it feels vital.

    I wonder if there will some day be a room we can go into that just shows our skeletons as they move about. There was an old Schwartzenneggar (sp?) sci-fi movie that showed something like that. It would drive all us scolis crazy with possibilities.

    Okay, I will exit stage left with the hijack! Thanks for all your contributions to this forum. So helpful...
    Amy
    58 yrs old, diagnosed at 31, never braced
    Measured T-64, L-65 in 2009
    Measured T-57, L-56 in 2010, different doc
    2 lumbar levels spondylolisthesis
    Exercising to correct

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    Quote Originally Posted by skevimc View Post
    Yeah, I would imagine that would be the case. There is a study in 2006 that used an axial loading device to compare standing versus supine MRI. The axial loading device recreated the results from the standing x-ray fairly consistently.

    I also wonder what progression would look like on a non-loaded scan. Would it suggest a different progression risk or outcome if a curve measured 25 while lying and 45 while standing versus 25 lying and only 35 standing? Hmm....

    Do you all have a research DEXA?
    The progression point is interesting, but if, as I suspect, the difference lies in the amount of rotation, a scoliometer would probably give us the same information (and without any radiation).

    Is a research DEXA different than a regular DEXA?

    --Linda

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    Quote Originally Posted by LindaRacine View Post
    The progression point is interesting, but if, as I suspect, the difference lies in the amount of rotation, a scoliometer would probably give us the same information (and without any radiation).

    Is a research DEXA different than a regular DEXA?

    --Linda
    That's very true about the rotation. It's another weakness I'd thought about.

    A research DEXA is different than a regular/clinical DEXA in that it costs much less/free That makes studies much easier to do.

  9. #9
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    Quote Originally Posted by skevimc View Post
    A research DEXA is different than a regular/clinical DEXA in that it costs much less/free That makes studies much easier to do.
    Thanks. I didn't have a clue. I'd be shocked if we didn't have one, but I'll have to do a little searching.

    --Linda

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    Quote Originally Posted by skevimc View Post
    But I was wondering if anybody here had come across any other studies that really looked at the difference of standing versus lying measurements.
    I think my daughter has a gap of about 50 degrees. http://www.scoliosis.org/forum/showthread.php?t=10546
    When I see her spine spine so straight I want to 'freeze' it. The only way I can imagine is using a brace. That way when she stand up, her spine remains straight all the day. I think I should to do it, but I can not imagine if could exist risks ..I'm getting out of topic ..
    I realized that a way to be sure whether she reduces so many degrees or is just an optical illusion, is to measure her height standing up and lying down. If the difference is about 3 cmts, then it is true that reduces all these grades. I made a trigonometric calculation of how much she would grow aligning her spine (with a triangular approach) and gave me 3 cmt.
    Last edited by flerc; 05-25-2010 at 03:03 PM.

  11. #11
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    Quote Originally Posted by skevimc View Post
    When we were discussing how to apply resistance in our home therapy portion of the study I suggested lying supine and legs straight (or bent) in the air. Then rotate left, then right, etc... This would ensure a trunk rotation and would basically be impossible to cheat. Or at least very difficult. We decided against it because of what you suggested, i.e. that the muscles would work differently in the lying down position so they might not be as effective. However, as you mentioned, perhaps it would also add something.

    I do these exercises during some of the yoga I do. This portion of the ab workout is brutal. You really have to stabilize your pelvis and fire every abdominal muscle you have in order to control your movement. Bending the knees helps reduce the resistance. But it's a great rotational/ab exercise.
    I think the best is to put a semi-rigid brace while lying, so that when you stand up, it help you to keep your spine straight and to not loose derotation, but muscles must to help too, otherwise the curve will turn up again. Once standing, putting 20 to 30 kg on their shoulders and walk with the spine straight for several hours.
    What do you think? It's so crazy?

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    Well, walking for several hours with 20 or 30 kgs is surely exaggerated.
    What about 5 or 10 kgs and walking only one half hour?

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    Quote Originally Posted by flerc View Post
    Well, walking for several hours with 20 or 30 kgs is surely exaggerated.
    What about 5 or 10 kgs and walking only one half hour?
    I think this is the basic concept of CLEAR therapy.

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    Quote Originally Posted by skevimc View Post
    I think this is the basic concept of CLEAR therapy.
    Clear use EDF technique? This is in fact the basic concept.

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    Quote Originally Posted by flerc View Post
    Clear use EDF technique? This is in fact the basic concept.
    skevimc, Ill open a thread about EDF. Just only say by now that in fact I think that with only that exercise (or the best of the world) some minutes by day, would not do so much in a great curve if disks are compressed again when exercise is finished. EDF avoid that possibility. I also feel curiosity to know which is the exercise of Clear similar to these. I read about a vibratory chair that lead to confuse the neuromuscular and balance system or something like that. We could talk about this in the next thread if you prefer.

    Regards.

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