Radiographic assessment of calcifying tendinitis of the rotator cuff : an inter- and intraobserver study


Rotator cuff ; calcific tendinitis ; classifications ; radiographs ; agreement ; reliability

Published online: Feb 13 2021

Jan K.G. Louwerens, Femke M.A.P. Claessen, Inger N. Sierevelt, Denise Eygendaal, Arthur van Noort, Michel P.J. van den Bekerom

From the Department of orthopaedic surgery, Spaarne Gasthuis Hospital, Hoofddorp, The Netherlands & Shoulder & Elbow Platform collaborators


The radiographic appearance of calcific tendinitis of the rotator cuff varies according to the stage of the disease. We compared currently used classification systems in a large group of observers to identify the most reliable classification system. Thirty-seven orthopaedic surgeons evaluated shoulder radio- graphs of 25 patients to classify the stage of the calcific tendinitis according to the classifications by (1) Gärtner and (2) Molé on a Web-based study platform. Inter and intraobserver agreement among observers was measured using the Siegel and Castellan multirater κ. Both classification systems had fair interobserver agreement : κ was 0.25 for the Molé classification and 0.34 for the Gärtner classification. The Gärtner classification was significantly more reliable than the Molé classification. Currently there is no radiographic classification that can serve the purpose of guiding the treatment in a reliable way.