It is a mechanical conflict between the tendons of the head of the bone and the acromion, which is a bone structure of the scapula situated just above.
The causes of this conflict:
- The space through which the tendons slide is narrowed because of this phenomenon of arthrosis, by the shape of the acromion which looks like a bone beak.
- The repeated movements of the shoulder attack the tendons : painting, bricklaying or any repetitive action of daily life.
Consequences of this conflict:
- Tthe emergence of an inflammation of the tendons which can consequently wear out or break.
It is a very frequent pathology since the coraco-acromial arc is rigid and aggressive (especially the outer end of the coraco-acromial ligament). The tendons are often stuck between the humerus head and the coraco-acromial ligament during the abduction or the rising of the arm. These repeated traumas may provoke the wear of the head of the rotators and may be sometimes at the origin of the breaking. Numerous professional or sports activities favour these traumas.
The tendinitis (also commonly called ‘periarthritis’) of the head is very frequent : 30% of the population suffer from degenerative injuries of the rotators’ head at about 50 years old, and the incidence increases with age.
The shoulder joint or glenohumeral joint is a synovial joint between the humeral ball and the glenoid cavity, strengthened by the fibro-cartilaginous ring, the glenoid ring. The joint’s capsule is reinforced by 2 or 3 ligaments. It is wide and loose on its lower part.
Most of the joint’s stability 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 and little round muscle at the back
They are inserted into the proximal part of the humerus via their tendons which form a fibrous tissue blade difficult to separate from the joint capsule below: the head of the rotators.
Above the head, but separated from the latter by the sub-acromial purse, lies the arc constituted by the acromion (a bone structure of the scapula located just above the humeral head ) and the coraco-humeral ligament.
The patients complain about a dull pain in the shoulder, with no accurate topography but very often located at the front of the shoulder with an irradiation of the pain all along the arm when moving it. The pain often occurs at night and can wake the patient up.
On examination, active mobility is often slightly reduced because of the pain, particularly during lateral elevation or abduction. Passive mobility is not limited but there is a painful arc during lateral or anterior elevation.
The various tests on the head of the rotators are painful, but with a normal resistance that can often show the absence of tendinous break.
When X-rays are done, they will reveal most of the time a reduced space between the acromion and the humeral head, and often the presence of an acromial beak.
If no treatment is considered, the wearing out and the inflammation of the tendons will carry on developing leading little by little to an ulceration (a non-transfixing perforation) of the tendons, entailing little by little a transfixing perforation and tendinous break which will make the functional prognosis of the shoulder even worse.
The pains will worsen, especially at night.
The operation, which then becomes necessary, will thus be longer and the result more uncertain.
The treatment’s aim is to reduce the pain, to re-establish as well as possible the shoulder’s functioning, to prevent further complications, particularly the evolution towards a breaking of the tendons and to educate the patient so as to avoid the coming back of this affection.
The failure of the medical treatment confirms the evolution towards a chronic form of the disease, requiring a surgical operation.
It consists in a resection of part of the acromion as well as that of the coraco-acromial ligament: this operation is called ‘acromioplasty’.
Of course it is accompanied by a cleaning of the tendons so as to eliminate all the inflammation. This operation is carried out under arthroscopy through 2 incisions less than 1cm wide.
Before the operation: presence of an aggressive bone beak.
After the operation: bone beak has been retrieved
Anaesthetic complications :
They have nothing to do with the specific arthroscopic surgery. The anaesthetist supplies all information during the pre-op consultation.
Local complications :
Vascular complications :
The main blood vessels (arteries, veins) may be exceptionally affected, which can have serious consequences; with less serious consequences, other little veins can be affected, and lead to a joint haematoma of the shoulder called: haemarthrosis.
It is a post-op infection of the joint. It occurs rarely: - 0.4% of all arthroscopies. The treatment requires another operation with an arthroscopic cleaning of the joint and an adapted antibiotics treatment.
It consists in a large and painful blood shed in the joint.
A stiffness (retractable capsulatis) of the shoulder may occur.
This complication in surgery may also occur outside of all operating gesture. It seems to affect most frequently women over 40. Its symptoms are a decalcification of the shoulder along with invalidating pains. We can often observe a redness of the skin, an increase in sweating, heat, a stiffness of the joint. It requires a functional and medical treatment with a slow re-education. It can also be provoked by unsuitable physiotherapy. It usually goes away spontaneously. It is cured over a period of a few weeks, but it may go on for up to two years.
Nerve complications :
An anaesthesia of an area of the skin around the scar and even localized itches may occur through an affection of the little nervous branches located under the skin. Generally, these unpleasant sensations diminish with time.
A swelling or a serious oedema of the shoulder :
May occur and usually diminish during the first post-op night without any aftermath.
The patient will leave the clinic the same day as the operation without being immobilized or in plaster. An immediate moving of the upper limb will be done while taking the pain into account.
Pain care is shared between the anaesthetists, your surgeon and the nurses on duty.
When you leave the clinic, your surgeon will give you the prescriptions relating to painkillers, dressing, re-education, leave from work if necessary and the next appointment. Of course, your GP will have a surgical account and a mail to explain the therapeutic gesture carried out and the consequences to be envisaged.
When you leave, you must quickly make an appointment with your physiotherapist. Your surgeon will deliver a prescription with a re-education protocol; this re-education will have to be easy, careful and progressive.
You may envisage to resume your activities only after about 6 weeks.
It will naturally be in relation with your degree of physical activity and your profession. The daily life gestures will be carried out quickly, but without any strenuous work.
The patient usually feels a significant improvement about his shoulder after only three months, both regarding the functioning and the pain.
The patient will have re-education sessions as long as pains or a functional impotence of the shoulder persist.