Acromial apohysiolysis is a finding on shoulder MRI that may be encountered in patients with an unfused acromial apophysis. It is associated with athletes in throwing sports.
Presents with superior shoulder tenderness in a patient <25 years old, often in a young throwing athlete (~100 pitches/week in American baseball). May clinically mimic a shoulder labral tear.
Repetitive stress across a meta-acromion-meso-acromion type unfused acromion. The injury is analogous to epiphysiolysis at incompletely fused growth plates.
STIR / PD FS
- increased signal intensity across an unfused acromion
- STIR sequence is useful to avoid inhomogeneous fat suppression
- decreased signal intensity across an unfused acromion
Treatment and prognosis
Patients are usually treated conservatively, with rest and NSAIDs.
- in a throwing athlete with shoulder pain, edema signal intensity across an unfused acromial apophysis, and no other cause for shoulder pain consider acromial apophysiolysis
- 1. Roedl JB, Morrison WB, Ciccotti MG et-al. Acromial apophysiolysis: superior shoulder pain and acromial nonfusion in the young throwing athlete. Radiology. 2015;274 (1): 201-9. doi:10.1148/radiol.14140587 - Pubmed citation
- 2. Pagnani MJ, Mathis CE, Solman CG. Painful os acromiale (or unfused acromial apophysis) in athletes. J Shoulder Elbow Surg. 2006;15 (4): 432-5. doi:10.1016/j.jse.2005.09.019 - Pubmed citation