a close-up of a mri

Os acromiale

Diagnosis certain

A 40-year-old lady with chronic hand pain after 3 months ago trauma and distal radius fracture with following wrist casting

  • unfused accessory center of ossification of the acromion of the scapula without causing rotator cuff impingement
  • Os acromialeis relatively common, seen in ~8% (range 1-15%) of the population and can be bilateral in 60% of individuals .
  • The subtypes develop due to the fusion pattern of the three acromial ossification centres (preacromion, mesoacromion and meta-acromion)  and are classified on their pattern of articulation with the acromion (from proximal to distal) :
  • basiacromial
  • meta-acromial
  • mesoacromial
  • preacromial

Meta- and mesoacromial are the most common .

An Os acromiale is readily identified if care is taken to examine the acromion in the superior axial plane as it can easily be mistaken for the normal acromioclavicular joint.

 

  • Kaplan P. Musculoskeletal MRI. W B Saunders Co. (2001) ISBN:0721690270. Read it at Google Books- Find it at Amazon
  • Papatheodorou A, Ellinas P, Takis F et-al. US of the shoulder: rotator cuff and non-rotator cuff disorders. Radiographics. 26 (1): e23. doi:10.1148/rg.e23- Pubmed citation
  • Haaga JR, Boll D. CT and MRI of the whole body. Mosby. (2009) ISBN:0323053750. Read it at Google Books- Find it at Amazon
  • Butler P, Mitchell A, Healy JC. Applied Radiological Anatomy. Cambridge University Press. (2012) ISBN:0521766664. Read it at Google Books- Find it at Amazon
[case_author_box]

Same Cases