Acromion Classifications
- Acromion morphology: Bigliani Classification
- Acromion morphology based on sagittal oblique MRI: Epstein Classification
- Os Acromiale Types: Liberson
- Types of scapular notch: Rengachary
Acromion morphology: Bigliani Classification
Type 1: Flat, 17%
Type 2: Curved, 43%
Type 3: Hooked, 40%
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Acromion morphology based on sagittal oblique MRI: Epstein Classification
Epstien R E et al, Radiology,187: 479-481, 1993
Type 1- flat
Type2- smoothly curved
Type 3- hooked
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Os Acromiale Types: Liberson
Lieberson F, JBJS 19:683-689, 1937
Incidence 1.4%
Type1: non-union between meso and meta acromion (typical os acromiale)
Type 2: non-union between pre and meso acromion
Type 3: non-union between pre and meso as well as meta acromion
Type 4: non-union between pre and meso acromion, meso and meta acromion as well as meta and basi acromion
Types of scapular notch: Rengachary
Rengachary et al, Neurosurgery, 5:447-451, 1979
Type 1: No notch, 8%
Type 2: blunted ‘V’ shape, 31%
Type 3: symmetrical ‘U’ shape, 48%
Type 4: small , narrow ‘V’ shape, 3%
Type 5: Type 3 but with ossified medial part of ligament, 6%
Type 6: Completely ossified bony foramen, 4%
