KALK study: ultrasound guided needling and lavage (barbotage) with steroid injection versus sham barbotage with and without steroid injection - protocol for a randomized, double-bl... oleh Stefan Moosmayer, Ole Marius Ekeberg, Hanna Bjørnsson Hallgren, Ingar Heier, Synnøve Kvalheim, Jesper Blomquist, Are Hugo Pripp, Nils Gunnar Juel, Stein Harald Kjellevold, Jens Ivar Brox, KALK study group