As for your concern about UCSD, most programs do exactly that... your advancement into the susequent year is predicated on your performance in the previous year(s). That isn't to say that you are recompeting for your ortho spot all over again... it is yours. But, if someone turns out to be a screw-up, that person doesn't have the "right" to continue on in the program and the program can replace them. This is something that I think is almost universal for residency programs.

I believe UC Davis has a few 5 y spots and a few 6 y spots.

UC-Davis has two 5 year spots and a 6 year spot. they are listed as two separate match numbers, so if you are totally against 6 years, you don't even have to rank that possibility. but, if you are willing, you get two ranks for one interview.

Davis actually has THREE 5 year spots, plus ONE 6 year spot, for 4 total per year.

I was just upset that UC-SD requires MCAT scores on the application. Are there lots of places like this? How lame.