# Clinical implications of reverse total shoulder arthroplasty with an os acromiale: a systematic review

## TL;DR

This study reviews the effects of a shoulder condition called os acromiale on the outcomes of a specific shoulder surgery called reverse total shoulder arthroplasty.

## Contribution

This is the first systematic review to evaluate clinical outcomes of reverse total shoulder arthroplasty in patients with os acromiale.

## Key findings

- Os acromiale prevalence in rTSA patients ranged from 5% to 22%.
- Patients with os acromiale showed improved outcomes with minimal complications after rTSA.
- Inferior tilting of the os acromiale was the most common radiographic finding.

## Abstract

Os acromiale is defined as a developmental failure of fusion of one of the primary ossification centers of the acromion. This anatomic variant can be identified in the presentation and workup of patients with various shoulder pathologies. Reverse total shoulder arthroplasty (rTSA) is a common surgical procedure for a multitude of underlying conditions. The purpose of this study was to conduct a systematic review of the literature to determine the clinical implications of rTSA in those with os acromiale.

This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses: the PRISMA checklist. In April 2024, the following online databases were accessed: PubMed, Embase, and Cochrane. All clinical studies assessing os acromiale in rTSA were considered for inclusion and evaluated.

The initial search result provided 569 studies to be assessed. After careful screening, 4 studies were included in this systematic review. A total of 573 patients undergoing rTSA with underlying os acromiale were included in this review. The prevalence of os acromiale in patients undergoing rTSA ranged from 5% to 22%. All patients had improvements in patient reported outcome measures with minimal complications. The most common radiographic finding was inferior tilting of the os acromiale.

The presence of os acromiale does not appear to have a negative impact on the clinical outcomes after surgery and rTSA remains a safe and effective treatment option.