Reverse Total Shoulder Arthroplasty in Patients with Os Acromiale: A Systematic Review of Clinical and Radiographic...

Background/Objectives: This study aims to conduct a systematic review to determine the clinical and radiographic outcomes and postoperative complications of reverse total shoulder arthroplasty (RTSA) in patients with os acromiale. Methods: A systematic review was conducted according to PRISMA guidelines. Studies investigating outcomes of RTSA in patients with os acromiale were included. Data regarding prevalence, clinical outcomes, range of motion, complications, and radiographic findings was extracted. Results: Six studies were included involving a total of 161 patients with os acromiale who received an RTSA. Os acromiale was present in approximately 6.4% of the total RTSA cases. Comparative studies reported no significant differences in clinical outcomes, complication rates, or reoperations between patients with and without os acromiale. One study with consecutive follow-up evaluations reported postoperative acromial tenderness in up to 27% of patients, which resolved spontaneously in most cases. Radiographic inferior displacement of the os acromiale occurred in 54% (range: 28-63%) of cases, but did not correlate with worse functional outcomes. Conclusions: Os acromiale does not represent a contraindication to RTSA and does not significantly compromise clinical outcomes. Radiographic acromial tilt often occurs without clinical relevance. Preventive surgical fixation of the os acromiale is not routinely recommended. Nonetheless, acromial tenderness may be present postoperatively, with a high likelihood of spontaneous symptom resolution.