Posterior shoulder dislocation: presentation, recurrence, treatment options and rehabilitation
Posterior shoulder dislocation: a rare trauma that's difficult to detect
Posterior glenohumeral dislocation of the shoulder is difficult to diagnose. First and foremost, it is a rare trauma, accounting for less than 3% of all shoulder dislocations. Diagnosis is not straightforward, and requires a high-quality clinical examination.
The challenge of immediate detection is, however, a challenging one: late detection of the pathology often leads to a stiff, painful shoulder, and this chronicity leads to complex surgery, not always followed by recovery.
What is a posterior shoulder dislocation?
The most common posterior shoulder dislocation involves the arm being internally rotated and held in adduction. Its external rotation is limited, as are its elevation possibilities.
Dislocation is most often caused by direct or indirect high-energy trauma, such as a violent anteroposterior shock, or by convulsive seizures: epilepsy, alcoholism or electroshock.
Dislocations of this type are difficult to detect at first glance, and do not always lead to the correct procedures being applied when treating shoulder pathologies. This is why they often recur, because they are not treated in time or are not properly assessed. The shoulder remains painful, with highly disabling glenohumeral instability, the major risk being avascular necrosis of the humeral head.
>Why is glenohumeral dislocation difficult to diagnose?
A patient with a glenohumeral dislocation presents with a stiff, painful shoulder on examination. Initially, the naked eye reveals no change in the shoulder's curvature, nor any particular swelling. Palpation also fails to reveal any changes in appearance.
On closer examination, radiology is not always able to detect it either, as the clinical signs of posterior shoulder dislocation are not loud enough on x-ray, hence the importance of the axillary view.
To avoid misjudging the trauma, the practitioner will need to apply a strict and exhaustive examination, particularly for the radiological examination, in order to properly detect rounding of the humeral head due to internal rotation of the limb and loss of congruence of the joint.
What treatment options are available for posterior shoulder dislocation?
Immobilization of the shoulder and closed reduction under narcosis is indicated to reduce pain and improve healing potential, depending on the patient's age, stamina and state of fitness. Surgical techniques that tend to restore anatomy (grafting, osteosynthesis, etc.) have better results than so-called non-anatomical techniques (arthroplasty, rotational osteotomy, McLaughlin subscapularis tendon transfer, etc.).
Depending on the protocol, the arm may be immobilized for 45 days before rehabilitation begins, but surgeons such as Christophe Charousset recommend early self-education from D0 to D21, with training in active shoulder positioning (internal bell and humeral plunger), mobilization in the plane of the scapula, in passive, active aided then active free, from decubitus to sitting position, and finally static and dynamic contractions of all shoulder muscles, but especially the subscapularis, in the authorized sector. This is followed by active recovery of mobility in all sectors and muscle strengthening, proprioception and plyometrics. In throwing sports, the Thrower's Ten Program (TTN) rehabilitation protocol can be applied.
Shoulder rehabilitation with the Allyane method
Posterior shoulder dislocations, particularly in young women, often have a strong emotional component, and it's with this in mind thatAllyane offers an innovative, non-invasive global rehabilitation method. The primary aim of neuromotor reprogramming is to rebuild the muscle tone and balance required for function and movement, while also reducing pain. Rather than focusing on treating pain, the aim is to restore the shoulder's motricity using a low-frequency sound generator and motor mental imagery. Low-frequency sounds put the brain into alpha mode, a kind of hypovigilance that optimizes kinesthetic visualization and provides a bridge between the voluntary conscious and the subconscious. These proprioceptive visualization techniques unconsciously modify our muscle tone and normalize our spatial and temporal recruitment during voluntary movements. These modifications take place in a mirror-therapy type of work, shifting sensations from the healthy to the pathological side using a mental imagery protocol guided by the therapist.
This involves reafferenting two key muscles that are often centrally inhibited to protect the joint: the serratus anterior and subscapularis.
The serratus anterior or serratus major is the guarantor of scapulothoracic stability, a sine qua non for a functional shoulder. It shows elective amyotrophy and recruitment deficits from the very first days of immobilization. It is vital to reafferent it with mirror therapy from the healthy side.
The subscapularis is considered an internal rotator of the humerus, but it's much more than that. Nicolas Blanchette perfectly underlines the sub-scapular's preponderant role in shoulder biomechanics. It is far from being a simple internal rotator. This internal rotation function is overshadowed by the much more powerful pectoralis major and dorsalis major. The subscapularis lowers the humeral head during shoulder abduction. Together with the other cuff muscles, it thus counterbalances the superior force exerted by the deltoid. Without this function, soft-tissue compression by the humeral head in the subacromial space (where there is a large bursa) would be greatly increased.
The subscapularis tendon blends with the anterior shoulder ligament capsule, playing a stabilizing and protective role. It stabilizes the anterior humerus. In other words, it prevents the humeral head from sliding too far forward. It is also the most powerful stabilizer of passive external rotation at zero degrees of abduction. It therefore plays a vital role in preventing dislocation during violent movements.
The lower part of the tendon blends with the transverse humeral ligament, which encapsulates the tendon of the long head of the biceps. Together, they form the key mechanism for stabilizing the long head of the biceps during shoulder movements.
According to recent studies, the upper part of the subscapularis tendon also plays a significant role in humeral abduction, a function similar to that of the supraspinatus muscle.
Allyane neuromotor reprogramming will therefore aim to :
- reafferent these two key muscles for glenohumeral stability,
- remove motor inhibitions and improve muscular play in the shoulder complex, thanks to a general relaxation protocol,
- The result is a rapid return to function and, ultimately, a significant reduction in pain.
It's probably in complex pathologies such as posterior dislocation of the shoulder, with a strong emotional connotation, that the Allyane concept finds its full raison d'être: a non-invasive, rapid and long-lasting method.
Are you a healthcare professional with questions about the Allyane method? Do not hesitate to contact our team by telephone on 04 28 29 48 14 or by email on contact@allyane.com
Do you have any questions about Allyane sessions? Contact our medical secretary on 04 28 29 58 10 or contact@allyane.com.