The purpose of this study is to determine whether the combination of removal of the calcification in calcific tendinitis of the shoulder (supraspinatus and/or infraspinatus tendon) by aspiration with a needle and syringe (barbotage) and a corticosteroid injection is more effective than corticosteroid or sham injection alone.

Barbotage is a sonographically guided percutaneous needle aspiration and lavage of the calcium deposit in calcific tendinitis of the shoulder. Persisting pain in cacific tendinitis is considered to be a consequence of increased tendon volume or changed tendon texture in the area of the calcification which leads to secondary impingement and inflammation. Consequently, removal of the deposit should be a causal treatment measure.

Scientific evidence for the efficacy of the barbotage procedure in patients with persistent symptoms from calcific tendinitis is still limited. The cyclic often self-limiting course of the disease, and an anticipated placebo effect, questions about the method's efficacy can only be answered by high-quality randomized studies. In this trial the investigators want to randomize a cohort of patients to (1) Ultrasound guided needling, lavage and subacromial steroid injection, (2) Ultrasound guided subacromial steroid injection or (3) Ultrasound guided lidocain injection (sham). The investigators want to follow the patients over two years with repeated testing with a set of validated outcome measures together with radiologic re-examinations. The investigators want to find out whether the active treatments (1, 2) are more effective than the sham treatment and whether there are differences in outcome between the two active treatments. To increase the generalizability of the investigators' results, the investigators want to perform the study as a multi-centre study.

Inclusion Criteria:

1. 30 years or older
2. 3 months or more of shoulder pain
3. Moderate to strong pain localized on the top and/or lateral side of the shoulder, exaggerated by activities above shoulder level
4. Painful arc
5. Positive Hawkin's test and/or Neer's sign for impingement
6. Finding of one or more calcifications ≥5 mm in size on a standard anteriorposterior radiograph, localized proximally to the greater tubercle, together with a sonographic finding of one or more calcifications ≥5 mm in size on the short or long axis view, localized in the supraspinatus or infraspinatus tendon
7. Morphological radiographic appearance of Molé type A, B or C12 (appendix 2) A: Dense, homogeneous with well-defined limits B: Dense, fragmented with well-defined limits C: Heterogeneous with poorly defined limits and sometimes with a punctuate appearance
8. Ability to understand written and spoken Norwegian (Swedish/English)
9. Existing signed informed consent and expected cooperation of the patients for the treatment and the follow-up

Exclusion criteria:

1. Clinical and radiological signs of a recent spontaneous release of the deposit such as a sudden change in size or density of the deposit on ultrasound together with an acute onset of extreme shoulder pain
2. Clinical signs of shoulder instability, glenohumeral arthritis, AC pathology, inflammatory arthropathy, fibromyalgia, frozen shoulder or cervical radiculopathy
3. Sonographic signs for a rotator cuff tear (full thickness or partial thickness) and of a tear or a dislocation of the long head of the biceps tendon
4. A history of surgical treatment of the relevant shoulder
5. A subacromial injection with a corticosteroid during the last 3 months before inclusion
6. Medical contraindications for any of the invasive procedures
7. 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.
8. 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.
9. 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.
10. Any history of prior allergic/hypersensitivity reactions related to the study medication
11. 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)
12. Nursing women