Prevalence of os acromiale in an indigenous East African population: a computerized tomography scan-based study

Background: Failure of fusion to any of the acromion physes at maturity may lead to an os acromiale. A radiological review into the prevalence of os acromiale in an indigenous East African population was performed using computer tomography (CT) imaging. The study aimed to demonstrate a lower prevalence of os acromiale in an urban population compared with cadaveric studies. Methods: This was a cross-sectional study with consecutive sampling. CT scans of both shoulders obtained for non-shoulder pathology were used for the analysis. CT scanning was performed at a tertiary referral hospital from January 2019 to July 2020. Results: Nine hundred eighty-two CT studies were eligible for the review. There were148 os acromiale identified that were either pre-acromiale or meso-acromiale. The study found a 15% prevalence of os acromiale among an ethnic East African population, of which almost 40% were meso-acromiale and 60% were pre-acromiale, with no meta-acromiale. Conclusion: The prevalence of os acromiale found in this study is similar to that observed in earlier cadaveric studies.