In this study, the morphology of the acromion in neonatal cadavers was
investigated. The hooked-type acromions (Bigliani and Morrison type I
II), which are said to be responsible for rotator cuff lesions in adul
ts, were found to have a very low incidence in this age group (5%). Th
is finding challenges the validity of the assumption that some individ
uals have a congenital tendency for rotator cuff lesions, depending on
their acromion types.