The Many Names


You like 'to-may-to', I like 'to-mah-to'




If you are new to the literature on hypermobility, you are likely to get confused with the different names used to describe this condition and other related conditions.

BJHS, HMS, JHS, H-EDS  and recently, EDS-HT are the most common abbreviations you will come across in literature. What do they mean and how are they different from each other? And do the names matter?

Here are some explanations to make things clearer.

What are ligaments?



Ligaments are connective tissue that join bones to bones in a joint. Muscles arise from one bone and insert into another bone by forming tendons. When muscles contract, they make the bone, the joint and the body part move.

What is hypermobility of joints?

The relative stiffness or laxness of ligaments determine the extent of mobility at a joint and the hyperlaxity of ligaments lead a joint to move to an abnormal extent. A joint can have hyperlax ligaments also due to habitual wrong posture using that joint or habitually doing a movement where the muscles are not supporting the joint well. But it can also occur due to a structural abnormality of the ligaments, like a constituent protein called collagen and possibly other proteins as well.

In case of hypermobility syndrome, there is a genetic abnormality that leads to defective coding for collagen - leading to a multisystemic heritable disorder of connective tissue affecting not just teh musculoskeletal system but also many other bodily systems [1].

If the muscles are strong and flexible, they prevent damage to ligaments. As Katy says in her blog explaining hypermobility, the muscles are the brakes of a joint and the ligaments are the seatbelts.
Lax ligaments cannot support the joint well, and may lead to subluxation (partial dislocation) or dislocation of a joint. 


Are joint hypermobility (JHM) and joint hypermobility syndrome (JHS) the same?

No. Joint hypermobility per se is not a disorder or a disease that requires treatment. If a bad postural habit is causing it, the person may benefit from posture and body alignment training to keep their ligaments from getting lax or damaged. It can also be beneficial or desirable and deliberately achieved in some professions, like ballet dancers. Yoga practitioners also have some hypermobile joints. When hypermobility of the joints leads to other symptoms in the body, it is called joint hypermobility syndrome.

How is hypermobility of joint assessed? 

Assessment of hypermobility of joints is not routinely taught in the textbooks to doctors. Therefore, there is a lack of knowledge even among doctors regarding hypermobility and they miss it because they do not look for it. There have been many criteria described to assess and describe the hypermobility of joints. At present, the Beighton score is commonly used to assess hypermobility and Brighton criteria is used to diagnose joint hypermobility syndrome [2, 3]. 

What is HMS?


Hypermobility syndrome or HMS was coined in 1967 by researchers who reported on joint hypermobility leading to musculoskeletal symptoms in some individuals [4].

What is JHS?

Other researchers subsequently mentioned hypermobility of joints in connection with the term "joint hypermobility syndrome", or JHS [5].

JHS = HMS

What is BJHS?

BJHS is Benign Joint Hypermobility Syndrome. As far as I could find, the word benign was used by researchers from Virginia to describe hypermobility of joints which was not associated with rheumatic or cardiac symptoms [6]. They concluded:
"Thus the benign hypermobile joint syndrome appears to be one extreme of the range of normal joint motion and not a systemic connective tissue disorder."

The term BJHS was used by some researchers in 1996 in a study that found that individuals with hypermobility did not have any other systemic abnormalities and thus their joint hypermobility was benign [7]. Their conclusion was:
"Thus, patients with BJHS do not have an increased prevalence of significant cardiac, bone, skin or eye abnormalities, helping differentiate BJHS from other more serious hereditary disorders of connective tissue."

The titles like "Is hypermobility benign" and the phrase "not so benign" started appearing in the nineties itself [8, 9]. Through the nineties and the noughties more and more studies started showing the life changing, debilitating nature of hypermobility syndrome in adults and in children, and more and more people started adding the phrase "not so benign multi system disorder" to describe JHS. Also, patients also found each other on the net and they too started objecting to the adjective "benign", because it sounds dismissive about a condition that is devastating to many people around the world.

What is EDS-HT?

EDS-HT is Ehlers-Danlos Syndrome, hypermobility type. Ehlers-Danlos Syndrome is a group of connective tissue disorders classified into several types depending on the clinical presentation. At present, most eminent authorities on this disease are of the opinion that hypermobility syndrome is the same as Ehlers-Danlos Syndrome Hypermobility Type (also described as H-EDS in many studies), which was previous known as EDS type-3. The underlying pathophysiology is considered to be the same and this disease is understood to manifest in a spectrum of severity, therefore there being considerable differences among patients in their symptomatology. It is often said by experts that if you get diagnosed by a rheumatologist, you are likely to get the diagnosis of hypermobility syndrome, where as if a geneticist sees you, he is likely to diagnose the same condition as EDS-HT. Until the genetic mutations and pathophysiology are understood in greater detail, these ambiguities will remain. However, there is enough evidence now that

HMS = JHS = BHJS = EDS-HT = HEDS 

So the answer to my earlier question is, yes, the names do matter. Drop the word benign. Do not try to downplay the pain, difficulties and sadness of millions who have this condition. Do not trivialize my life of losses. And this blog is just a way to make my life mean more than the sum total of my losses. 

It is high time the experts sat down together and achieve a consensus on an appropriate name.

Anything but BJHS

========================================================================

UPDATE Feb 2017: A new article by Castori et al proposes a new classification system. See here.


                                                                                                                                                           

References:

[1] Malfait, F. R. A. N. S. I. S. K. A., et al. "The genetic basis of the joint hypermobility syndromes." Rheumatology 45.5 (2006): 502-507.
[2] Beighton, P. H., L. Solomon, and C. L. Soskolne. "Articular mobility in an African population." Annals of the rheumatic diseases 32.5 (1973): 413.

[3] Grahame R, Bird H. "The revised (Beighton 1998) criteria for the diagnosis of benign joint hypermobility syndrome (HMS)". J Rheumatol 27 (2000): 1777–9.

[4] Kirk, J. A., B. M. Ansell, and E. G. Bywaters. "The hypermobility syndrome. Musculoskeletal complaints associated with generalized joint hypermobility." Annals of the Rheumatic Diseases 26.5 (1967): 419-425.
PDF available at http://ard.bmj.com/content/26/5/419.full.pdf

[5] Handler, CLIVE E., et al. "Mitral valve prolapse, aortic compliance, and skin collagen in joint hypermobility syndrome." British heart journal 54.5 (1985): 501-508.
PDF available at http://heart.bmj.com/content/54/5/501.short

[6] Jessee, E. Forrest, Duncan S. Owen, and Kiran B. Sagar. "The benign hypermobile joint syndrome." Arthritis & Rheumatism 23.9 (1980): 1053-1056.

[7] Mishra, M. B., et al. "Extra-articular features of benign joint hypermobility syndrome." Rheumatology 35.9 (1996): 861-866.
PDF available at http://rheumatology.oxfordjournals.org/content/35/9/861.short

[8] El-Shahaly, Hassan A., and Assem K. El-Sherif. "Is the benign joint hypermobility syndrome benign?." Clinical rheumatology 10.3 (1991): 302-307.

[9] Yathish, G. C., et al. "Benign Joint Hypermobility Syndrome–not so ‘Benign’." Internet Journal of Rheumatology and Clinical Immunology 3.1 (2015).