title: Acromial morphology: relation to sex, age, symmetry, and subacromial enthesophytes.
abstract: OBJECTIVE
  To evaluate acromial shape in relation to age, sex, symmetry, and presence of subacromial enthesophytes.
  
  
  METHODS
  Three hundred ninety-four cadaveric scapulas were reviewed. Specimens were categorized by sex and age (age range, 20-89 years). Acromial morphology was typed according to the Bigliani classification: type I, flat; type II, curved; and type III, hooked. The presence and degree of subacromial enthesopathy was recorded. Selective radiographic correlation was obtained.
  
  
  RESULTS
  The relative percentages of acromial types I, II, and III were 22.8% (90 acromions), 68.5% (270 acromions), and 8.6% (34 acromions), respectively. There was a greater percentage of type III in men (10.2% [21 of 205] vs 6.9% [13 of 189] and type I in women (27.5% [52 of 189] vs 18.5% [38 of 205]). There was no relationship between acromial type and age (P = .667). Enthesophytes were most common in type III (20 [59%] of 34 acromions) versus type II (115 [42.6%] of 270 acromions) and type I (22 [24%] of 90 acromions). Acromial morphology was symmetric in 135 (70.7%) of 191 pairs of acromions and asymmetric in 56 pairs (29.3%).
  
  
  CONCLUSIONS
  Acromial shape does not vary significantly with age. It does, however, differ between sexes. The relative percentages of the types differ from previously reported values. Acromial shape tends to be symmetric. A trend between acromial type and the presence of enthesophytes is observed.
authors.affiliation: Cleveland Clinic Foundation, OH 44195, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Getz
authors.forename: M P
authors.initials: MP
authors.lastname: Recht
authors.forename: D W
authors.initials: DW
authors.lastname: Piraino
authors.forename: J P
authors.initials: JP
authors.lastname: Schils
authors.forename: B M
authors.initials: BM
authors.lastname: Latimer
authors.forename: L M
authors.initials: LM
authors.lastname: Jellema
authors.forename: N A
authors.initials: NA
authors.lastname: Obuchowski
mesh_terms: D000174:Acromion / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D002102:Cadaver; D005260:Female; D006801:Humans; D008022:Ligaments / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011859:Radiography; D012727:Sex Characteristics; D013710:Tendons / Q000033:anatomy & histology* / Q000000981:diagnostic imaging