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