Multidirectional shoulder (glenohumeral) instability, (MDI) is a common symptom/complication of generalised joint hypermobility. It is usually an atraumatic, bilateral condition characterised by recurrent subluxations/dislocations in two or more directions, i.e. anterior, posterior and/or inferior. Multidirectional shoulder instability may be described medically as AMBRII (Atraumatic onset of multidirectional instability, accompanied by bilateral laxity/hypermobility.) The shoulder joint is a multiaxial ball-and-socket joint attached to the axial skeleton via the clavicle at the sternoclavicular joint. Stability is sacrificed for flexibility. The shoulder joint is mainly stabilized by the glenohumeral ligaments and unlike the hip-joint, another ball-and-socket joint, the joint lies superficial rather than deep, a factor which further increases both flexibility and the risk of instability. Shoulder instability is common.
Rehabilitation through intensive physiotherapy focused particularly on strengthening the rotator cuff muscles is the first step in treatment. If no improvement is seen after 12 months, surgery, like a capsulorraphy to tighten the inferior capsule and the rotator interval may be considered. As usual, the prognosis for MDI is generally good, except in the presence of an underlying collagen disorder, like EDS. Surgery is not recommended for those with EDS, although it may be considered as an option despite the risks if long-term conservative treatment proves unsuccessful.
I’ve suffered from MDI for more than a decade through various rounds of intensive physiotherapy and creative bracing. Surgery has been suggested, but I don’t feel the odds on that are in my favour. For those with EDS, surgery often simply leads to more surgery as stretchy ligaments have a tendency to stretch out gradually after tightening and soon need tightening again. I have significant skin issues that have caused stitches to tear out, wound healing to be delayed, abnormal unsightly scarring and bleeding is a significant risk. In my view, a year or two after the surgery I would most likely have my MDI back in addition to the ordeal surgery would’ve been with an outlook of yet another surgery on the horizon. Thankfully, my Rheumatologist agrees and support my decision.
Usually, multidirectional instability is seen in the absence of trauma, but in those with EDS, it may be seen in conjunction with traumatic shoulder dislocations. I developed MDI before I suffered any of the injuries that caused traumatic shoulder dislocations. I still experience both spontaneous and traumatic subluxations and dislocations. Traumatc dislocations are much worse and require medical treatment, but we’ve become pretty adept at dealing with most of it at home. Thankfully, the standard rules do not apply and sometimes that’s a plus rather than the usual minus.