Cherington said Pedroia had the less complicated ligament surgery on his thumb. No issues expected. #redsox— Pete Abraham (@PeteAbe) November 13, 2013
The more-complicated version of the procedure, which would require a tendon from his wrist to be taken to replace the damaged one in his thumb, is (to simplify things massively, I'm sure) not unlike Tommy John Surgery for the thumb. The major difference being that it would have extended Pedroia's recovery time by all of a couple of weeks, still leaving him ready to go months in advance of spring training.
Still, it stands to reason that the less complicated the procedure--the less fiddling needed to make it all work--the better.