title: Ultrasonographic appearance of os acromiale.
abstract: OBJECTIVE
  Ossa acromiale are rare anatomical conditions and have been evaluated with plain radiographs, CT- and MRI-scans, but not with ultrasound. The purpose of this study was to evaluate the appearance and the characteristics of os acromiale with ultrasound.
  
  
  METHODS
  25 patients with unilateral radiologically prediagnosed os acromiale had bilateral examination with ultrasound. Recorded details were bilateral appearance, the width of the non-ossified space and the shape of the bony margins of the os acromiale. As a control group 25 patients without radiological appearance of os acromiale had identical ultrasound examination.
  
  
  RESULTS
  The os acromiale could be identified in all 25 patients (100%) with radiologically confirmed os acromiale. In 12 patients an os acromiale could be identified on the contralateral side (48%). The average width of the non ossified space was 4.3 mm (2.5 to 7.6 mm). Three different sonographic types of bony margins of the os acromiale and the acromion exist: Type I with flat bony margins; Type II with marginal osteophytes and Type III with inverted bony margins. In the control group no os acromiale could be identified.
  
  
  CONCLUSIONS
  With ultrasonographic assessment, os acromiale can be accurately identified in each case. Three differently shaped bony margins exist. Ultrasound can give additional information about the os acromiale if radiological assessment is unclear because of superimposing bones.
authors.affiliation: Department of Orthopaedic Surgery, Koenig-Ludwig-Haus, University of Wuerzburg, Germany. dr.dirkboehm@web.de
authors.forename: T D
authors.initials: TD
authors.lastname: Boehm
authors.forename: W
authors.initials: W
authors.lastname: Kenn
authors.forename: M
authors.initials: M
authors.lastname: Matzer
authors.forename: F
authors.initials: F
authors.lastname: Gohlke
mesh_terms: D000174:Acromion / Q000000981:diagnostic imaging*; D000328:Adult; D000368:Aged; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D008875:Middle Aged; D009999:Ossification, Heterotopic / Q000000981:diagnostic imaging; D017006:Rotator Cuff / Q000000981:diagnostic imaging*; D000070636:Rotator Cuff Injuries; D014463:Ultrasonography