Table 1 Inclusion criteria

Age of 30 years or older

3 months or more of shoulder pain

Moderate to severe pain localized on the top and/or lateral side of the shoulder, exaggerated by activities above shoulder level

Pain at night when lying on the affected shoulder

A painful arc [32]

A positive Hawkin’s test [33] or Neer’s sign [34] for impingement

A finding of one or more calcifications ≥5 mm in size on a standard anterior posterior radiograph, localized proximally to the greater tubercle, taken not more than 4 weeks prior to the intervention

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

A morphological radiographic appearance of Molé type A, B or C [13]

The ability to understand written and spoken Norwegian (Swedish)

An existing expected cooperation of the patient for the treatment and the follow-up