I never heard anything about this, but the Blue Jays sent out this press release:

Following the 2012 season, Toronto Blue Jays LHP RICKY ROMERO underwent arthroscopic surgery performed by Dr. Lewis Yocum to clean up his left elbow. The recovery time for this routine procedure is approximately six weeks. Romero also received PRP treatments to both knees to enhance the recovery of his quadriceps tendinitis.

Romero's off-season throwing program and his readiness to participate in Spring Training will not be affected by these procedures.

It sounds like is was pretty minor, hopefully he'll be all ready to go by spring training and all will be well.