Shoulder pain and periarthritis; what to do ?
Some shoulder pain is called "periarthritis": what does this term mean, and what can be done?
Most of the time, "periarthritis" means that the patient has pain when raising the arm, often with a feeling of blocking at 90 degrees of elevation (arm horizontal). These pains can occur spontaneously or be triggered by trauma.
In the drawing below, we see the shoulder joint. The pain is caused by impingement between the tendon of the supraspinatus muscle and the bone called the acromion, which is actually part of the shoulder blade.
The infraspinatus is part of a set of tendons which surround the head of the humerus and which is called "the rotator cuff". On the image above, we see the entire rotator cuff, with wear of the supraspinatus by friction under the acromion.
Treatment is usually started by making an "infiltration" (injection) between the acromion and the tendon, using a small amount of cortisone. This has the effect of rapidly decreasing the inflammation, and sometimes the "periarthritis" is cured.
You can also inject PRP (platelet rich plasma) , which has a longer lasting effect.
Sometimes, unfortunately, the symptoms return after some time: it is then necessary to push further the investigations, and to make x-rays and magnetic resonance.
Below, the left x-ray shows normal space between the acromion and the head of the humerus. On the image on the right, we can see that the acromion is "hooked": this explains why the symptoms persist.
The MRI shows the impingement area (arrow): the impingement lasted for many years, and caused a rupture of the tendon:
This rupture can be due to wear and tear, but also sometimes to trauma: a fall on the shoulder or on the hand, during sports or at work.
When the symptoms do not subside after an infiltration, it is sometimes necessary to have recourse to surgery: the simplest intervention is called "acromioplasty". This involves removing the hooked part of the acromion, using different instruments, to obtain more space for the tendon, as shown below:
This operation can be done either openly or by arthroscopy; this last technique is minimally invasive, and involves only a few small incisions (“small holes”) around the shoulder.
Sometimes it is necessary to carry out a more important operation, with a small incision in addition: the reconstruction of the rotator cuff, by which the torn tendons are reinserted on the humerus.