Joint hypermobility: emerging disease or illness behaviour | by Rodney Grahame
Joint hypermobility syndrome is a common clinical entity which is much misunderstood, overlooked, misdiagnosed and mistreated. It was first described in the 1960s as a purely musculoskeletal condition due to joint laxity and hypermobility occurring in otherwise healthy individuals.
Some four decades later it is now perceived to be a multi-systemic heritable dis- order of connective tissue with manifestations occurring far beyond the confines of the locomotor system and with ramifications potentially affecting most, if not all, of the bodily systems in one way or another.
Most authorities in the field find it clinically indistinguishable from EDS type III, the Ehlers-Danlos syndrome hypermobility type.
In > 50% of patients the diagnosis is delayed for 10 years. Failure to diagnose and treat the condition correctly results in needless pain and suffering and in many patients to a progressive decline in their quality of life and in some to a loss of independence.
There is a common tendency in medicine when faced with medically unexplained symptoms to assume that they are psychogenic in origin.
This is a high-risk approach that can have disastrous consequences. The joint hypermobility syndrome (JHS) story is a good illustration of this.
The realisation that the joint hypermobility syndrome (JHS), as HMS is now principally known, is a multi-systemic illness rather than a mild (seemingly trivial) mechanical disorder of lax joints in otherwise healthy subjects was slow to dawn and even slower to consolidate.
When the evidence came, it did so from multiple and sometimes unlikely sources. It is a process that is still unravelling as it becomes increasingly clear to hypermobility-watchers that there is hardly a single medical specialty that is untouched by the condition
HMS was regarded (by rheumatologists) as a purely rheumatological disorder in otherwise healthy individuals who happened to be at the upper end of a spectrum of normal joint mobility.
With the passage of time and the advent of new knowledge, it has become clear to clinicians seeing many of these patients that, to all intents and purposes, the two diseases are indistinguishable from one another.
The tragedy is that it took four decades to achieve this consensus. Sadly, even today, there are sceptics who do not yet accept this hypothesis and fervently advocate the separation of the two conditions. For them (principally, but not exclusively, rheumatologists), lax-jointed patients with HMS are ‘otherwise healthy subjects’ whose extra-articular symptoms are taken to represent illness behaviour, rather than bona fide symptoms of systemic complications of EDS III
Thus far, seven key elements, unearthed over the course of nearly half a century, have served to transform our understanding of the nature of JHS, and thereby shape our current concepts of the condition.
- The overlap with established HDCTs (Heritable Connective Tissue Disorder)
- The important association with uterine and rectal prolapse
- The association with chronic pain
- The relevance of anxiety and phobic disorders
- The high prevalence of dysautonomias
- The impact of gastrointestinal dysmotility
- The progression to major physical disability – the new ‘rheumatological disability
Many people who inherit the defect remain symptom-free throughout their lives, whereas others may develop minimal mus- culoskeletal symptoms after unaccustomed exercise. The full panoply of complications does not appear all at once, but gradu- ally over the first 2–3 decades of life.
The natural history of JHS can be seen to comprise three principal phases.
- The first phase results from connective tissue laxity and fra- gility and comprises multiple soft tissue injuries, joint and spinal instability and dislocation, and complications of weakness in supporting structures (pelvic floor, herniae and varicose veins).
- Phase 2 is the superimposition of non-articular complications: pain amplifi- cation, kinesiophobia deconditioning (widespread chronic pain often described as ‘fibromyalgia) and fatigue (which is often promi- nent and may be misdiagnosed as CFS/ME). It is in this phase that orthostatic intolerance, PoTS and other dysautonomic features as well as GI symptoms make their presence felt.
- The final phase is the emergence of psychosocial sequelae such as anxiety or depression, obesity (often associated with comfort eating), work incapacity, isolation and despair. There is often a downward spiral of loss of mobility, self-efficacy and self-esteem as the quality of life diminishes.
The reasons for this decline are complex and multifactorial. At this stage, the patients are severely disabled in spite of the fact that their musculoskeletal system is usually grossly intact. It would appear that the combination of overriding chronic pain (which is largely unresponsive to analgesics) and systemic components (PoTS and GI problems) is the determining factor in this decline.
Far from being a minor disorder occurring in essentially normal individuals, as is perceived by many of our colleagues even today, there is abundant evidence of a multisystemic hypermobility-related disorder that causes much suffering in the community.
This is an emerging disease, which bears little resemblance to the joint hypermobility diseases originally described in the 1960s. To dismiss disparate symptoms as ‘illness behaviour’ is, in my view, wrong and does much disservice both to our patients and to our reputation as a profession.
More often than not, JHS is still overlooked, misdiagnosed and hence untreated.