Inter- and Intraobserver Reliability of the Radiographic Diagnosis and Treatment of Acromioclavicular Joint Separations

The management of acromioclavicular joint separations, in particular Rockwood types III and V, remains controversial. The purpose of this study was to investigate the observer reliability of shoulder surgeons when presented with the same cases of acromioclavicular joint separations. The authors retrospectively identified 28 patients who were diagnosed with a type III, IV, or V acromioclavicular joint separation. A PowerPoint presentation was compiled that contained an anteroposterior and axial radiograph from each patient prior to treatment. Radiographs were sent to surgeons, who diagnosed each injury according to the Rockwood classification and stated whether they recommended operative or nonoperative treatment for each patient. Inter- and intraobserver reliability were calculated from the surgeons' reviews. Repeat diagnoses were returned by 8 surgeons. A single-measure intraclass correlation coefficient (ICC) was used to determine interobserver reliability for the surgeons' Rockwood classifications (ICC=0.602) and their decision to operate (ICC=0.469). Intraobserver reliability also was calculated for Rockwood classifications (rho=0.694) and decision to operate (kappa=0.366). Two (25%) of 8 surgeons stated that they would have used open and arthroscopic techniques for repairing the dislocations, whereas the remaining (75%) surgeons would have performed open techniques. Individual surgeons were consistent in their grading of acromioclavicular joint dislocations, but less observer agreement existed among the surgeons. Poor agreement among surgeons for the decision to operate indicates that this decision is heavily influenced by clinical factors and the radiographic classification.