Calcifying tendinitis of the shoulder

Calcifying tendinitis of the shoulder is an acute or chronic painful disorder that is characterized by calcifications in rotator cuff tendons.

The main clinical symptom is shoulder pain, often aggravated by lying on the shoulder or elevation of the arm above shoulder level. The patient may be awoken from sleep by the pain. Other complaints may be weakness, stiffness, snapping or catching of the shoulder. Diagnosis is based on the clinical features of the disease and on imagery.

The disease usually presents in four stages:
(i) precalcific stage (usually without symptoms), involving fibrocartilaginous metaplasia within the tendon;
(ii) formative phase (with or without pain), with calcific deposits formed in the fibrocartilaginous matrix;
(iii) resorptive phase (massive pain), with deposits disappearing by cell-mediated resorption (inflammatory response); and
(iv) final stage (with or without pain), involving healing and rotator cuff repair. Notably this cycle can be blocked at any one stage in chronic calcifying tendinitis.

The initial treatment should be conservative including rest, physiotherapy, and nonsteroidal anti-inflammatory drugs. In later stages, radial shock wave therapy (RSWT) should be considered (not in the resorptive phase), or subacromial infiltration with corticosteroids. Surgery should be considered for recalcitrant cases of calcifying tendinitis of the shoulder.