Hernandez-Ortiz EG, et al. - Patients undergoing revision of a previous anatomic total shoulder arthroplasty (TSA) were assessed for relative preoperative radiographic evaluation with intraoperative video and explant analysis. Assessment of preoperative radiographs of 165 revisions of failed TSAs for component loosening and glenohumeral registry (ie, the spatial relationship of the glenoid component and the prosthetic humeral head) was done and evaluation of 79 intraoperative videos for component stability, rotator cuff (RC) integrity, synovitis, and glenoid bone loss was undertaken in addition to reviewing 87 explants to assess wear patterns and presence of backside cement. Of 79 glenoid components, 47 were radiographically loose, but only 30 of 79 were loose intraoperatively. Observations revealed that radiographic evaluation of glenoid loosening often differed from intraoperative findings in patients undergoing revision of TSAs (40% false-positive rate and 17% false-negative rate). RC deficiency could be predicted via assessment of glenohumeral registry, with posterior and anterior registry associated with RC deficiency. Higher tendency for severe synovitis and more severe glenoid bone deficiencies was noted among patients with a loose glenoid. Asymmetrical wear of the glenoid component was more frequently observed with failed TSAs, suggesting altered pathomechanics that may have led to failure.