Definition of acromio-clavicular joint dislocation:
An acromio-clavicular joint dislocation is a dislocation of the acromion and the clavicle; this trauma shouldn't be confused with gleno-humeral shoulder dislocations which are dislocations between the humeral head and the glenoid of the scapula. Acromio-clavicular joint dislocation is a frequent traumatic pathology of the shoulder, resulting from a violent fall on the point of the shoulder.
Video of arthroscopic surgery for acromio-clavicular joint dislocation:
Diagnosis of acromio-clavicular joint dislocations:
In early forms, no shoulder deformity is visible, the clinical examination only reports exquisite shoulder pain when palpating the acromio-clavicular joint. At this stage, shoulder surgery is not necessary.
However, in this shoulder injury, dislocation between the acromion and the clavicle can extend to the coraco-clavicular ligaments (between the scapula and the clavicle), this is known as omoclavicular dislocation (between the shoulder blade and the clavicle). In this case a piano key of the clavicle forms under the skin. In these severe traumatic forms, specialist shoulder repair surgery must be performed.
This x-ray shows the shoulder opposite the injured one, with the joint between the acromion and the clavicle perfectly centred.
On the side of the injured shoulder, however, there is a loss of articular contact and at the point of the shoulder, it is possible to see the clavicle protruding under the skin.
Surgical treatment of acromio-clavicular joint dislocations:
In this arthroscopic shoulder surgery, only 3 mini-incisions are needed, one superior 3,5 cm away from the free edge of the clavicle and 2 arthroscopic portals, one anterolateral for optics and one anteromedial for instruments.
Dissection begins in the subacromial interval of the shoulder and then, following the acromiocoracoid ligament, the inferior edge of the coracoid is found. The acromioclavicular ligament will thus be perfectly preserved; besides it can be used to reinforce the surgical repair in forms treated belatedly. The inferior edge of the coracoid is released gradually until its process is visible at one extremity and the conjoint tendon at the other extremity.
A target guide is then introduced for a coaxial tunnel to be opened between the clavicle and the coracoid. First a pin is introduced, whose perfect centring under the coracoid is verified, then a cannulated drill bit and finally, through the cannulated drill bit, a guide can be passed and retrieved from the anteromedial incision.
A relay thread can then be passed, which will allow the implant to be positioned between the clavicle and the coracoid. Once the implant is positioned, it is put under tension so as to achieve reduction of the coracoclavicular interval and then the acromio-clavicular joint of the shoulder. The relay thread can be removed.
In dislocations that are treated early, the surgical procedure ends here.
This is the x-ray of the reduction, with the 2 plates of the implant perfectly positioned, one over the clavicle, the other underneath.
Recovery of the shoulder after acromioclavicular joint dislocation surgery
The shoulder needs bandaging for 2 weeks, scarring at the shoulder is minimal. The shoulder must be immobilized for 1 month. Specialized rehabilitation starts after 3 weeks. Daily life activities can resume at 4 weeks, forceful movements such as rugby can resume at 3 months.