Jonathan Edwards
Senior Member (Voting Rights)
Dr. Edwards, you mentioned that ligaments more or less (I am paraphrasing here) either snap or are the way they are predestined by your genetics and that you doubt that that an inflammatory process could increase the laxity of this type of tissue.
I have to say I that my own experience (and that of a hundred patients with EDS that I spoke too, not exaggerating here) says otherwise, but I can absolutely not prove it, I also do not know if that process that changed my ligaments and or joint mobility is of an inflammatory nature, but I do know the process exists, such as there is a sudden worsening in my and other patients joint laxity after „crisis“ like infection and/or antibiotic use.
This is an observation that many EDS clinicians also made.
I am one of maybe no more than a score of musculoskeletal physicians worldwide who have made connective tissue structure, pathology and biomechanics a special interest. I used to write the chapters in textbooks on connective tissue physiology. I still sometimes get things wrong but the situation here is pretty clearcut I think.
Along the length of a ligament the maximum stretch is set by the collagen fibres - like a rope. Just like a rope you cannot lengthen it without damaging so many fibres that it tears. So we can discount inflammatory or enzymatic effects leading to ligament lengthening without snapping along their length.
The place where a ligament gets longer during growth, and yes, @Skycloud, during pregnancy a bit, is at its attachment or enthesis. There is a transition zone of cells that are neither bone cells nor ligament cells but sort of 'superglue cells'. In inflammatory diseases like rheumatoid arthritis this area can undergo change so that the bone at point of attachment is eroded away and the ligament may possibly lengthen. I say possibly because the normal mechanism for ligaments getting lax in inflammatory conditions like RA is something quite different. It is that the bearing surface of joints and discs are eroded away, making them loose in the way that a worn axle gets loose - the ligaments are actually unchanged.
The long and the short of this is that for basic physics reasons ligaments can only get laxer if bone or cartilage is removed either at the attachment or a bearing surface. (During growth the situation is different because the attachment is growing - paying out new ligament on demand. So during childhood ligaments can become lax through growth.)
Removal of bone or cartilage shows easily on an x-ray if it is enough to allow laxity. In RA and pregnancy we see the bone dissolved. In EDS as far as I know there has never been any suggestion of this. There would be no reason because the genetic basis is in defects in the structure laid down during growth. There is no suggestion of a genetic tendency to inflammation.
I do not know how to interpret a sense of increased laxity after an acute illness. The only thing I can think of is that if one loses weight the mobility of certain joints increases because they are naturally limited by muscle or other tissues (elbow flexion for instance).
I would be very surprised if real EDS specialists thought this could occur. But then I would distinguish EDS specialists in the sense of clinical geneticists, who by and large do not see hEDS because there is no gene, and the 'EDS specialists' who diagnose all hypermobility as 'hEDS' and associate it with widespread pain and fatigue. I have reason to think the latter mostly do not know anything much about connective tissues.