Dictionary.net

• This was so called from its consisting of three branches, uniting above in one common trunk. The latter part was traversed by a long screw, having below a kind of hook, and above a handle for turning it. By turning the screw, the hook was drawn up, and the bone thus elevated. The simple lever is the only one now used, owing to the want of facility and advantages in the use of the others.

1846 - Medical lexicon: a dictionary of medical science
By Robley Dunglison