(Chapter 25) Footnote 2:

Or more accurately xei/r a/)krh, in On Fractures 9.2. In the 1543 Fabrica, Vesalius’ summa manus for “hand” imitates Galen’s a)/kra xei/r, employed because Gk. xei/r can mean the arm or the hand and arm combined ( LSJ 2). Galen explains this usage at the beginning of Ch. 2 in Bk. III of De anat. adm. The Latin term is something of an affectation, as manus is not ambiguous in the same way as the Greek. Here as elsewhere in the 1555 edition, Vesalius substitutes manus for summa manus. Vesalius’ digression on nomenclature was also deleted from this point in the later edition and moved (with revisions) to the beginning of the narrative section. See note14 below.