The influence of postoperative acromial and scapular spine fractures on the results of reverse shoulder arthroplasty.

Fractures of the acromion or scapular spine are recognized complications of reverse arthroplasty. This study reviewed the outcome of reverse arthroplasties with such fractures and compared the results to arthroplasties without the fractures. A consecutive series of 125 reverse arthroplasties were reviewed for the development of a postoperative acromial or scapular spine fracture. Nine cases were identified, all treated nonoperatively. Five fractures occurred from falls, and the remainder were fatigue fractures. These results were compared to 67 patients with similar diagnoses in the series without such fractures. No significant differences existed between the 2 groups in terms of age, sex, side of surgery, or diagnosis. Preoperatively, both groups had substantial pain, limitation of motion, and poor American Shoulder and Elbow Surgeons (ASES) and Simple Shoulder Test (SST) outcome scores. No significant differences existed between the 2 groups. At minimum 1-year follow-up, results in the shoulders with fractures were improved. Mean visual analog score (VAS) was 4.0, flexion was 89.3 degrees, ASES score was 47.9, and SST score was 5.6. Nevertheless, these results were inferior to those in shoulders without a fracture, whose mean VAS was 0.7, flexion was 152.1 degrees, ASES score was 87.7, and SST score was 10.2. Nonoperative management was chosen in these cases due to a concern that stable fixation would not be obtained with surgery. Although the final outcome was diminished, these patients improved their preoperative state. A decision for surgical treatment will need to weigh the challenges of internal fixation with the incremental improvement that may occur with improved fracture healing.