Answer: Rolando Fracture

Rolando Fracture is a 3+ part intraarticular fracture at the base of the first metacarpal (ie thumb)

Reference: http://radiopaedia.org/articles/rolando-fracture

Don't confuse it with the Bennett fracture, ie only a single fracture line with 2 parts.

Maybe this will help. Bennett starts with a B which is the 2nd letter of alphabet and it has 2 fragments. Rolando = comminuted. It just may be stupid enough to remember!