Calcifying Tendinitis of The Shoulder
CALCIFYING TENDINITIS OF THE SHOULDER
Calcifying tendinopathy of the shoulder is a painful acute or chronic disorder characterised 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 the 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 AND TREATMENT
Diagnosis is based on the clinical features of the disease and on imagery.
‘The calcifications occur most commonly in the supraspinatus tendon (51%–90%) and least commonly in the subscapularis tendon (3%).’
The aetiology is largely unknown. It has been hypothesised that the condition may be related to hypo-vascularity-induced fibrosis and necrosis within the tendon with subsequent degeneration. The characteristics of an existing, symptomless calcific deposit may be changed by minor traumatic episodes, leading to acute symptoms. The condition may also be related to mechanical irritation by deposits when the arm is abducted and deposits impinge on the acromion.
The disease usually presents in four stages:
1. Pre-calcific stage (usually without symptoms), involving fibrocartilaginous metaplasia within the tendon;
2. Formative phase (with or without pain), with calcific deposits formed in the fibrocartilaginous matrix;
3. Resorptive phase (massive pain), with deposits disappearing by cell-mediated resorption (inflammatory response); and
4. 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 incidence is approximately 3% in the healthy population and approximately 7% in those with shoulder pain. The predominant age is 30 to 50 years. Women are two times more affected than men.’
In the later stages (except the resorptive phase), shock wave therapy should be considered.