ACROMIAL MORPHOLOGY - RELATION TO SEX, AGE, SYMMETRY, AND SUBACROMIALENTHESOPHYTES

PURPOSE: To evaluate acromial shape in relation to age, sex, symmetry, and presence of subacromial enthesophytes. MATERIALS AND METHODS: Thr ee hundred ninety-four cadaveric scapulas were reviewed. Specimens wer e categorized by sex and age (age range, 20-89 years). Acromial morpho logy was typed according to the Bigliani classification: type I, flat; type II, curved; and type III, hooked. The presence and degree of sub acromial enthesopathy was recorded. Selective radiographic correlation was obtained.RESULTS: The relative percentages of acromial types I, I I, and III were 22.8% (90 acromions), 68.5% (270 acromions), and 8.6% (34 acromions), respectively. There was a greater percentage of type I II 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 be tween 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 morpho logy was symmetric in 135 (70.7%) of 191 pairs of acromions and asymme tric in 56 pairs (29.3%). CONCLUSION: Acromial shape does not vary sig nificantly with age. It does, however, differ between sexes. The relat ive percentages of the types differ from previously reported values. A cromial shape tends to be symmetric. A trend between acromial type and the presence of enthesophytes is observed.