Osteoarthritis is the result of the progressive wear of the articular cartilage. When the cartilage is gone, the bone surfaces rub directly against each other causing pain and stiffness.
The shoulder is less frequently affected by osteoarthritis than the hip or knee, because it does not support the body weight.
Osteoarthritis of the shoulder is, however, not exceptional, especially after the age of 60. It is more common in women than in men, the two shoulders are often affected to varying degrees.
At first the pain occurs during movement. It then becomes almost constant, keeping the patient awake at night and feeling very uncomfortable when lying on the affected side.
The diagnosis is easily made on X-rays. Cortisone injections, hyaluronic acid and medical treatment may help relieve pain at an early stage.
What is a shoulder prosthesis ?
Shoulder prostheses have existed for over 30 years. The principle is the same as for hip prostheses.
There are different types of shoulder prostheses:
Anatomical total prostheses reproduce the original shape of the anatomical articular surfaces:
– On the humeral side by a convex metal component,
– On the scapular side by a concave polyethylene component.
The components may either be impacted by force or sealed with surgical cement into the bone.
These prostheses are indicated in shoulders with good bone stock and no rotator cuff tendon rupture.
Reverse total prostheses transform normal anatomy
– On the humeral side by a concave polyethylene component
– On the scapular side by a convex metallic component
Reversed prostheses are indicated in shoulders with rotator cuff tendons ruptures or deficiency.
The specific risks of this surgery are the same as for hip prostheses:
– Material intolerance or infection.
– Wear and loosening of the prosthesis in the long term.
What is needed before surgery?
– X-Rays and a CT scan of the shoulder are needed to establish a treatment plan.
– Pre-anaesthetic assessment.
– Any infection must be completely treated before the insertion of the prosthesis. A preoperative check is done and includes urine tests, dental X-Rays and blood tests.
The procedure is performed under general anaesthesia. Postoperatively a simple sling or a cushion protects the shoulder. The drain is removed after one or two days.
The hospitalization lasts a few days.
The fixation of the prosthesis is optimal at the time of surgery, so rehabilitation may be started immediately.
What is the postoperative rehabilitation protocol?
Postoperative rehabilitation is usually started during hospitalization.
Its purpose is to maintain the mobility of the shoulder while protecting the repair of tendons and ligaments around the prosthesis.
It is adapted to each case but the general pattern is in three phases:
– During the first 3 weeks, the mobilization of the shoulder is only passive, that is to say by the physiotherapist. Pulley-assisted exercises should be avoided.
Elbow, wrist and fingers should be moved and used as much as possible.
– Between the 3rd and 6th weeks, the physiotherapist will show you how to contract the muscles without causing movement: this is called isometric contraction.
The physiotherapist will also show you how to move your shoulder by yourself : this is called active assisted rehabilitation.
– After the sixth week, normal activity may be resumed.
Rehabilitation usually lasts 3 to 6 months, it must be gradual and painless.
What are the results?
The results depend on the initial state of the muscles, ligaments and bones .
Statistically 80% of patients regain a painless shoulder, but the mobility and strength are highly dependent on the initial condition.
– Osteoarthritis of the shoulder is debilitating because it compromises the function of the upper extremity.
– If conservative treatment is inadequate, the only effective treatment is a shoulder prosthesis .
– Mobility may be recovered according to the initial state of the muscles prior to surgery.
– Pain relief is almost constant after 3-6 months.
An informed consent form will be given before surgery. We hope to inform you as objectively as possible of the principles of intervention, but also of the risk of complications.