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Thread: Flexural-torsional buckling

  1. #1
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    Flexural-torsional buckling

    Med Hypotheses. 2011 Aug 30. [Epub ahead of print]
    Flexural-torsional buckling initiates idiopathic scoliosis.
    Karnezis IA.
    Source
    Back Care Network, Erythrou Stavrou 5, Maroussi 151 23, Athens, Greece.
    Abstract
    Initiation of the spinal deformity in idiopathic scoliosis (IS) has been attributed to an abnormal pattern of spinal growth during development. However, recent findings suggest that the earliest observable event in the pathogenesis of IS is a change in the shape of intervertebral discs with alterations in the shape of vertebrae being considered a secondary event. Starting from the previous description of the spinal deformity in IS as 'buckling' of the spine a new hypothesis describing the initial spinal deformity in IS as flexural-torsional buckling, a three-dimensional type of failure of axially loaded columns, is proposed. According to the new hypothesis the initiating event (the earliest observable event) in IS is flexural-torsional buckling developing from the flexible parts (intervertebral discs and ligaments) of the affected spinal motion segments. Since flexural-torsional buckling occurs in columns with a cross-section of one axis of symmetry characterised by a much greater in-plane than out-of-plane bending stiffness the new hypothesis predicts that the initiating condition (the condition promoting the initiation) of IS is 'flexibility anisotropy' namely significantly higher bending stiffness in lateral bending than bending stiffness in flexion-extension of a part of the spine. The parameter of 'flexibility anisotropy' as a factor for initiation of IS has never been suggested or tested before. The present hypothesis has implications in the research on the pathogenesis of IS as well as in the development of new methods for its treatment.
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    Welp, these guys are going to have to duke it out with the faction that seems to think IS is caused by a disorder of the nervous system (Carol Wise and cohorts).
    Sharon, mother of identical twin girls with scoliosis

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    Interesting! I'm not sure I fully understand, and would love for someone to translate, but still interesting. How is this counter to the latest genetic research? That is suggesting that the etiology lies in genes relating to the nervous system. And this one is talking about the first observable changes before the spine even curves. Sounds to me like two different steps along the path to scoliosis. Why can't they both be right? Either way, I love all this new research to get to the root of it all!
    1993, Age 13, 53* Right T Curve w/ Left L compensatory
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    Quote Originally Posted by mehera View Post
    How is this counter to the latest genetic research?
    These guys are suggesting that the first cause (the thing that sets the curvature in motion) is a change in the discs. That is NOT related to the nervous system as far as I know.

    Wise et al. are suggesting there is a genetic defect in the development of the nervous system. That doesn't overlap the disc issue.

    They can't both be right.

    These are just two of the many mutually opposing hypotheses. The hypotheses are all over the map which suggests the state of this research is still in its infancy.
    Last edited by Pooka1; 09-05-2011 at 09:31 PM.
    Sharon, mother of identical twin girls with scoliosis

    No island of sanity.

    Question: What do you call alternative medicine that works?
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    "We are all African."

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    change in the discs? what about the patients with scoli whose
    discs seem to be fine?
    what kind of "change" do they mean?

    jess

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    They just say change in disc shape in the abstract.

    The changes they are talking about are almost certainly painless and would seem fine given most kids do not have pain associated with IS.
    Sharon, mother of identical twin girls with scoliosis

    No island of sanity.

    Question: What do you call alternative medicine that works?
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    Most of the genetic studies done to date focus on going from no curve to some curve. Wise et al. did a review article on all that work. It includes the work of several labs over many years.

    A relatively smaller effort is the work of one lab (Ward, Ogilvie et al.) who looked at the genetics of going from a small curve to a large curve (or not).
    Sharon, mother of identical twin girls with scoliosis

    No island of sanity.

    Question: What do you call alternative medicine that works?
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    "We are all African."

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    Quote Originally Posted by Pooka1 View Post
    These guys are suggesting that the first cause (the thing that sets the curvature in motion) is a change in the discs. That is NOT related to the nervous system as far as I know.
    I didn't read it as a cause, so much as just the closest they've gotten to seeing where it starts. It could be the trigger or the first observable change after a trigger. But the predisposition toward that change could still come from your genes. Obviously this is all speculation and there's no reason to assume that these two hypotheses go together, I just don't see why they need to be mutually exclusive.
    1993, Age 13, 53* Right T Curve w/ Left L compensatory
    2010, Age 30, 63* or 68* (depending on the doc) Right T Curve w/ Left L compensatory

    http://livingtwisted.wordpress.com/

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    Quote Originally Posted by mehera View Post
    I didn't read it as a cause, so much as just the closest they've gotten to seeing where it starts.
    That's how I read it too. It's the first observable thing but that doesn't mean it is the first thing. But the first thing is not likely to be a problem in the nervous system if the second thing is a change in disc shape as far as I know. Disc shape is not under control of the nervous system per what I know.

    Disc shape could be the trigger or the first observable change after a trigger. But the predisposition toward that change could still come from your genes.
    The predisposition in all these hypotheses is that it comes from the genes. There are no non-genetic hypotheses being studied as far as I know. "It's all genetics" per one researcher no matter which hypothesis you favor. Ogilvie said all people with IS have common ancestors. That suggests a genetic mutation many generations back that is still propagating. The question at the moment is whether the genetic defect is affecting the disc development or the nervous system development or something else entirely. The research is all over the map which is why it was a bit eye opening that Wise announced that she thought the nervous system hypothesis was most likely correct. A review of the research only two years ago seemed to indicate that metabolic issues were being studied heavily. There is no agreement among the researchers is seems.

    Obviously this is all speculation and there's no reason to assume that these two hypotheses go together, I just don't see why they need to be mutually exclusive.
    Because there are different biological systems in the human body that control various things. Everything is not controlled by everything.
    Sharon, mother of identical twin girls with scoliosis

    No island of sanity.

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    Quote Originally Posted by Pooka1 View Post
    That's how I read it too. It's the first observable thing but that doesn't mean it is the first thing. But the first thing is not likely to be a problem in the nervous system if the second thing is a change in disc shape as far as I know. Disc shape is not under control of the nervous system per what I know.
    It could also be that the change in the discs is the 20th thing, and we're still missing steps 2 through 19. (If it isn't clear I chose 20 arbitrarily, just for the sake of discussion. My point is that until we fully understand it, everything should be left on the table.)

    Quote Originally Posted by Pooka1 View Post
    Because there are different biological systems in the human body that control various things. Everything is not controlled by everything.
    I could be way off here, but I think the nervous system might be the exception. It is what transmits information throughout the body. Just some basic info from wikipedia...

    The nervous system is an organ system containing a network of specialized cells called neurons that coordinate the actions of an animal and transmit signals between different parts of its body. In most animals the nervous system consists of two parts, central and peripheral. The central nervous system of vertebrates (such as humans) contains the brain, spinal cord, and retina. The peripheral nervous system consists of sensory neurons, clusters of neurons called ganglia, and nerves connecting them to each other and to the central nervous system. These regions are all interconnected by means of complex neural pathways....The nervous system is susceptible to malfunction in a wide variety of ways, as a result of genetic defects, physical damage due to trauma or poison, infection, or simply aging. The medical specialty of neurology studies the causes of nervous system malfunction, and looks for interventions that can alleviate it....In addition to physical damage, peripheral neuropathy may be caused by many other medical problems, including genetic conditions, metabolic conditions such as diabetes, inflammatory conditions such as Guillain-Barré syndrome, vitamin deficiency, infectious diseases such as leprosy or shingles, or poisoning by toxins such as heavy metals. Many cases have no cause that can be identified, and are referred to as idiopathic....
    1993, Age 13, 53* Right T Curve w/ Left L compensatory
    2010, Age 30, 63* or 68* (depending on the doc) Right T Curve w/ Left L compensatory

    http://livingtwisted.wordpress.com/

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    Quote Originally Posted by mehera View Post
    It could also be that the change in the discs is the 20th thing, and we're still missing steps 2 through 19. (If it isn't clear I chose 20 arbitrarily, just for the sake of discussion. My point is that until we fully understand it, everything should be left on the table.)
    Yes (or almost yes) if you only want to prevent scoliosis in future generations.
    No (or not necessarily) if you really want to help in a significant way much people suffering it today.

    It’s seems reasonable to believe that only knowing the first historical cause (necessary the same in all cases?) you may prevent it.
    It’s a fact that only the current causes should to be known to solve a problem. And also is a fact that is not needed to know all of them to solve every problem. And also is a fact too that not necessary historical causes should remains as current ones and in that case, knowing about them may not help to understand the problem.
    Even we may say is a fact that most of the current causes avoiding a spine to hold straight or stop a progression are known.

    So all it depends on what problem do you want to solve. The problem of people not born yet or the problem of the people living today.

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    Quote Originally Posted by mehera View Post
    It could also be that the change in the discs is the 20th thing, and we're still missing steps 2 through 19. (If it isn't clear I chose 20 arbitrarily, just for the sake of discussion. My point is that until we fully understand it, everything should be left on the table.)
    I see what you are saying but that would (should) mean that this work is totally unpublishable. There is some reason they suspected that the disc changes were primary or central to the curvature propagation. I did assume that that case was made just on the basis that it was published but that may not be the case.

    I could be way off here, but I think the nervous system might be the exception. It is what transmits information throughout the body. Just some basic info from wikipedia...
    Let me give you an example... the onset of puberty in under genetic control (sometimes as modified by environmental factors). It is not linked to the nervous system in any way to my knowledge. Disorders of the nervous system would not be expected to change the onset of puberty as far as I know. I picked this example because the onset of puberty in girls is scrutinized greatly with respect to AIS in girls. There are probably hundreds of other examples like that one.
    Sharon, mother of identical twin girls with scoliosis

    No island of sanity.

    Question: What do you call alternative medicine that works?
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    Quote Originally Posted by mehera View Post
    It could also be that the change in the discs is the 20th thing, and we're still missing steps 2 through 19. (If it isn't clear I chose 20 arbitrarily, just for the sake of discussion. My point is that until we fully understand it, everything should be left on the table.)
    Quote Originally Posted by flerc View Post
    Yes (or almost yes) if you only want to prevent scoliosis in future generations.
    No (or not necessarily) if you really want to help in a significant way much people suffering it today.

    It’s seems reasonable to believe that only knowing the first historical cause (necessary the same in all cases?) you may prevent it.
    It’s a fact that only the current causes should to be known to solve a problem. And also is a fact that is not needed to know all of them to solve every problem. And also is a fact too that not necessary historical causes should remains as current ones and in that case, knowing about them may not help to understand the problem.
    Even we may say is a fact that most of the current causes avoiding a spine to hold straight or stop a progression are known.

    So all it depends on what problem do you want to solve. The problem of people not born yet or the problem of the people living today.
    I‘m realizing that you not referred mainly to the 1° cause, but to the cause-effect chain. All what I said was about the ‘detective’s game’ of researchers to know that first cause.. as trying to know the origin of the Big Bang.
    It's true that this chain should to be known in any case, but not necessarily all of it. You may solve a problem knowing about only a part of the chain. Some parts are already known as the scoliosis vicious cycle, but of course is not enough to know about that chain to solve a problem. Some questions like those http://www.scoliosis.org/forum/showt...ight=pneumatic should to be answer.

    Trying to known the 1° cause may be something probably impossible, depending on the kind of problem. There are good (and really funny) examples about that given in Systems theory.

    And scoliosis seems to be an enough complex problem to think that it may happens.
    Suppose that the ‘1° cause’ is what ABR people says, something as a short neurologic dysfunction affecting internal organs leading then to the collapse of the pneumatic skeleton which in turn twist the spine. (a good example of an original cause not remaining as current one).
    As they want to help that people and know that cannot reverse the time, they are focused in the link of the chain corresponding to the pneumatic skeleton and try to recompose it reducing/stopping in that way the curve.

    But if you want to prevent scoliosis, you should to avoid the possibility of that neurologic disruption, so you should to know the causes provoking it. So it was not the first cause.
    Surely the same may be saying about other theories like that or http://www.sciencedaily.com/releases...0226204549.htm
    You may be focused in reduce the effects provoked by the asymmetry of vertebras or muscles or improve the regulation of functions performed by RERE or Nr2f2.. Or you may try to find the first cause leading some people to born with this defect in some genes.
    Maybe the regulation of that functions could not be improved so you should to try in other part of the chain. Something as the Backtracking strategy is needed.

    And also, supposing that researchers find in an absolutely uncertain future the REAL first cause, it not implies they will prevent the scoliosis problem. If they are ‘playing Dr. House’, may happen as in some chapter when of course he found the first cause, but... it was a disease without cure.
    Last edited by flerc; 09-07-2011 at 12:11 PM.

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    Quote Originally Posted by flerc View Post
    So all it depends on what problem do you want to solve. The problem of people not born yet or the problem of the people living today.
    Certainly, if you solve the problem of next generations preventing the scoliosis, you would not solve the problem of the people alive today, but if you help them finding a really acceptable solution (impossible only improving fusion techniques), the same solution may be used for people of next generation at least until someday the 1° cause may be avoided.
    But I really understand how much fascinating should to be for people not suffering this problem to ‘playing Dr. House’.

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    I'm not trying to solve anything, or stitch the research together in ways that the researchers aren't suggesting. It was a simple comment that got out of hand. My only point is just that just because different researchers are coming up with different "causes" doesn't mean that one is right and the others have to be wrong. It is a complex problem that could have more than one answer -- either for different types of scoliosis (possibly even classifications that don't exist yet), or that there are multiple factors that add up to the perfect storm of scoliosis, or that it is a chain reaction of events set off by one thing but that knowing any of the things along the way may help. Obviously the ideal is to understand everything we can that could help anyone with scoliosis whether they are not born yet or an adolescent just showing the first signs. Maybe even some day we will know enough that will lead to better solutions for untreated adults. But until then, I don't see any reason to argue over what is right and what is wrong. Everything is on the table.
    1993, Age 13, 53* Right T Curve w/ Left L compensatory
    2010, Age 30, 63* or 68* (depending on the doc) Right T Curve w/ Left L compensatory

    http://livingtwisted.wordpress.com/

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