Table 2 Exclusion criteria

The presence of clinical and radiological signs of a recent spontaneous release of the calcific deposit such as a sudden change in size or density of the deposit on ultrasound together with an acute onset of extreme shoulder pain

Clinical signs of shoulder instability, glenohumeral arthritis, AC pathology, inflammatory arthropathy, fibromyalgia, frozen shoulder or cervical radiculopathy

Sonographic signs of a rotator cuff tear (full thickness or partial thickness) or of a tear or a dislocation of the long head of the biceps tendon

A history of surgery or barbotage of the relevant shoulder

A subacromial injection with a corticosteroid or treatment by ESWT during the last 3 months before inclusion

Medical contraindications for any of the invasive procedures

One of the following contraindications for the use of Lidocaine 10 mg/ml: Patients with serious hypovolaemia, known cardiac conduction disturbances, epilepsy or porphyrias, patients with known serious dysfunction of the liver or the kidneys

One of the following contraindications for the use of Triamcinolone 20 mg/ml: Patients with systemic infections unless specific anti-infective therapy is employed, patients with a local infection in the area of application, patients recently vaccinated with live vaccines, patients with known diabetes mellitus, renal or cardiac insufficiency, ulcerating colitis, gastric ulcer, psychosis, idiopathic thrombocytopenic purpura or ocular herpes simplex

Concomitant medication with one of the following medicinal products: Anti-arrythmics such as mexiletine or class III antiarrythmics (e.g. amiodarone), muscle relaxants (e.g. suxamethonium) or antipsychotics (e.g. pimozide, sertindole, olanzapine, quetiapine, zotepine, tropisetrone, dolasetron), antibiotics such as quinopristin/dalfopristin, anticoagulants suchas warfarin (if INR > 2) or novel oral anticoagulants

A history of prior allergic/hypersensitivity reactions related to the study medication

Knowledge of an ongoing pregnancy (fertile women not using contraception and who are uncertain whether they are pregnant or not will have to perform a pregnancy test

Nursing women