The complex characteristics of 282 unsatisfactory shoulder arthroplasties.

The purpose of our study is to augment the knowledge of patient dissatisfaction after a shoulder arthroplasty. A total of 353 shoulders were prospectively enrolled into the Shoulder Arthroplasty Failure Experience (SAFE) project. Of these, 282 patients had complete data for the final analysis, including demographic information, medical history, physical examination, standard radiographs, and the Simple Shoulder Test (SST) scores. These data were analyzed to determine the frequency of 17 possible characteristics of an unsatisfactory arthroplasty. Pain was the most common reason for patients to seek an evaluation (241 of 282 shoulders). Shoulder function was substantially reduced at presentation, with patients only able to perform an average of 2.6 of 12 SST functions. Overall, technical factors such as component malpositioning and glenohumeral malalignment were the most common characteristics identified among all the shoulders. Loosening of glenoid components was noted in 85 of the 136 total shoulder arthroplasties, and glenoid erosion was found in 51 of 80 hemiarthroplasties performed for degenerative conditions. Patients with an unsatisfactory outcome after shoulder arthroplasty present with poor shoulder function and pain. Component malposition, glenohumeral malalignment, and glenoid failure are all prevalent features among patients with an unsatisfactory outcome.