I don't know where these figures are from but the consensus documents says that 135 or less is only potentially pathological. I suspect it's possible for people like gymnastics or ballet dancers to have a CXA lower than 135 but be perfectly healthy.
If you read either of the full Henderson papers on cxa I believe he says that the mathematical modelling (finite element annalysis) shows that anything below 150 or 145 is abnormal and potentially pathological , but that below 135 is a different category, like clearly pathological.
In the study i think he said that he included someone with a 139 cxa bc of their clinical picture indicating greater disability.
The cxa does seem like its emphasized the most, but it seems that Bolognese and these other surgeons put a clear emphasis on looking at more than one measurement at once and also sometimes response to traction, and clinical picture.
In this Swedish study the ME/CFS patients had a CXA of 148±10 degrees, which seems rather normal. That would be in contrast to the theory that a substantial subgroup of ME/CFS patients has very low CXA angles. So I'm not sure that the Swedish study should be seen as a confirmation of what Henderson, Bolognese en Gilete are saying.
In the Bolognese and Milhorat study that i posted in this thread and another thread, all of the supine measurements (cxa and others) were within normal range, and then when taken while upright, were quite different and clearly abnormal.
There were no healthy controls in this study (which is too bad) but there was a comparison between patients that had chiari plus connective tissue disorder, ans patients who had only a connective tissue disorder, and comparison between the measurements of cci on both of these populations.
The argument has been made that there are not studies validating these measurements as compared to controls, establishing a normal range, etc.
I can see this line of argument as valid but im not sure that we have enough information here to know how CCI used to be diagnosed and whether the measurements that used to be used (of which it seems the group that made the consensus statement has picked a few and simplified) had any more validation than cxa, Bai, etc.
In fact, it seems like perhaps, CCI has just not been an object of much research and interest and clinical practice until recently. So perhaps there just isnt a ton of data.
@Jonathan Edwards says, you dont need these measurements (which he points out do not have controlled studies , besides the mathematical modelling) to diagnose CCI, the compression is obvious on scans and clinical picture.
But is there any citations or body of evidence to show that the "old way" of diagnosing CCI is correct?
I would think that Bolognese or Henderson would have similar confidence in their own clinical judgment. But I think the history of these measurements and what the "normal range" is need to be clarified and we cant just rely on someone's clinical experience.
My perspective, which may be somewhere in the middle on this, is that I have confidence in bologneses acumen as a surgeon and innovation in surgical techniques, and confidence in his diagnostic abilities. But i do wish that some of these measurements were validated against healthy controls, which seems like it would be easy to do.
I dont think , personally, that dr b or Henderson have refused to do those kind of studies because they dont believe in science, I just think that it seems like neurosurgeons may see themselves more as artisans than scientists and be less interested in proving their findings than getting results clinically though.
So like i said i dont think theres any sinister reason for skipping the step of validating these measurements against controls. And im not sure if the "old way" of diagnosing based on eyeballing scans and more obvious clinical signs is any more validated than the methods we are discussing. But i do wish there were more studies on all of this.
Also, i still dont understand what a finite element analysis is. Anyone know?
