The shoulder’s joint is the most mobile in the body but the low congruence (humeral head - shoulder blade’s glene) makes it more prone to anterior dislocation than any other joint.
This fact is partly offset by :
-the capsulo-ligament structures
- the tendons of the rotators’ heads
This unsteadiness may appear in the aftermath of the shoulder’s dislocation or without any history of shoulder trauma, namely among hyperlax patients.
The shoulder’s joint or gleno-humeral joint is a synovial joint between the humeral head and the glene, strengthened by the fibro-cartilaginous ring, the glenoid ring.
The joint’s capsule is reinforced by 2 or 3 ligaments. It is broad and loose in its lower part.
Most of the stability of the joint is ensured by the muscles of the head:
The sub-scapula muscle at the front
The sub-spinal muscle at the top
The sub-spinal muscle and small round muscle at the back
They insert themselves into the proximal part of the humerus via their tendons, making up a fibrous blade difficult to sever from the underlying joint capsule: the head of the rotators.
Above the head, but separated from it by the sub-acromial purse, is the the arch made up by the acromion (a bone structure of the scapula located just above the humeral heads) and the coraco-acromial ligament.
In case of a typical reiterative dislocation, the problem of a diagnosis does not exist, and the unsteadiness is confirmed by the iterative dislocations. In the opposite case, the patient will often complain about a feeling of dislocation of the shoulder, sometimes painful, for typical movements with which the surgeon is well acquainted. Of course, in both cases, the clinical exam will be significant, and when manipulating the shoulder, what will be looked for will be an antero-posterior draw, the sign of the hollow line witnessing a lower laxity, or else the reluctance to making certain moves.
It will be necessary, sometimes, to confirm the diagnosis by X-rays:
- A plain X-ray of the shoulder might find a posterior notch on the humeral head or else a tearing of the antero-lower edge of the glene.
- The exam which will confirm the unsteadiness of the shoulder is the arthroscanner or the MRI which will show, most of the time, an injury of the glenoid ring.
Without any treatment, with patients who have already dislocated their shoulder, other dislocations will appear during movements which will be less and less traumatizing.
For other patients, the notion of instability with pains and dislocation will worsen with time.
In both cases, the middle-term evolution towards injuries of arthrosis is unavoidable and will require at that time a prosthesis of the shoulder.
There are two kinds of operation:
The bone End-stop (Latarjet’s operation)
The re-insertion of the ring and the capsule’s tension (Bankart’s operation under arthroscopy)
The Bone End-stop consists in removing a bone graft from a bone excrescence of the scapula in order to set it with a screw in front of the shoulder joint, enabling thus the head of the humerus to stay within the joint without any likelihood of dislocation. This operation is reserved to sportsmen or to patients who have a physical job. It requires a skin incision of about 5 cm on the anterior face of the shoulder, as well as an immobilization of 3 weeks after the operation, followed by sessions of re-education.
The second operation which consists in stitching the ring and stretching again the capsule is done entirely under arthroscopy through 2 or 3 holes. It consists in repairing the injuries caused by unsteadiness and re-stretching the various ligaments. It is effected with stitches and anchors that may be resorbed. It just requires the wearing of a sling during the night for a month after the operation, possibly followed by sessions of re-education.
They are not specific to arthroscopic surgery. The anaesthetist will provide you with all relevant information during the pre-operation consultation.
The main blood vessels: (arteries, veins) can exceptionally be affected, which may have serious consequences; with less serious consequences, other little veins may be hurt, which will lead to a haematome of the shoulder called haemarthrosis.
Complications of the nerves:
It may be possible to have an area of skin anaesthesia round the scar and even localized itches because of small nervous ramifications under the skin being affected. Generally, these unpleasant sensations diminish with time.
It is a post-op infection of the joint. It is not so frequent: -0.4% of all arthroscopies. The treatment requires another operation with an arthroscopic cleansing of the joint and a suitable antibiotics treatment.
It is a serious and painful blood flow in the joint.
A stiffness (retractable capsulitis) of the shoulder may appear.
Rare scar problems.
This complication in surgery may also occur outside of all operation gesture. It often seems to affect women over 40. Its symptoms are a decalcification of the shoulder joint along with invalidating pains. We often observe a redness of the skin, a rising of the sweating, heat, a stiffness in the joint. It requires a functional and medical treatment by easy re-education. It can also be provoked by unsuited physiotherapy. It usually disappears spontaneously. The recovery can be achieved over a few weeks but can also take up to 2 years.
Failure of the treatment by bone End-stop:
Reiteration of dislocations provoked by the breaking of the material set in or by the absence of consolidation of the bone End-stop: it will then be necessary to operate again and to implant a bigger bone End-stop (5% of the cases).
Failure of the Bankart’s operation under arthroscopy:
The various stitches come off (8% of the cases). It will then be necessary to realize a bone End-stop.
The stay in the clinic for the setting of a bone End-stop will last 48 hours because of the presence of a drain. The patient will leave with his shoulder immobilized for three weeks during which he will have passive re-education sessions with his physiotherapist.
As regards the Bankart’s operation under arthroscopy, the patient will be able to go back home on the same day as the operation and will only have to wear a sling during the night, without having any re-education sessions during the first month.
The patient will leave the clinic the same day as the operation without being immobilized and without any plaster. An immediate mobilization of the upper limb might be done depending on the pain.
Pain care will be shared between the anaesthetists, your surgeon and the nurses on duty. When you leave the clinic, your surgeon will give you the prescriptions for painkillers, dressing, re-education, work-leave if necessary and your next appointment. Of course your GP will receive an account of the operation as well as a mail explaining the therapeutic act carried out and the operating consequences to foresee.
On leaving, you will have to make quickly an appointment with your physiotherapist. Your surgeon will give you a prescription with a re-education protocol.
It is only possible to consider resuming one’s activity after a minimum of 2 months of course depending on the degree of the physical activity of the patient.
Everydayt gestures can be resumed immediately after the Bankart’s operation and after a month with the operation on the bone End-stop.
Strenuous physical tasks will only be possible after 3 months.
Whatever the technique that has been used, the strength and the mobility of the shoulder should be recovered entirely from the 3rd or 4th month onwards.
The shoulder should be entirely stabilized after 3 months, once the muscular recovery has been completed.