Our pointer/dalmation mix has had both rear acl's go. In the first case it was a partial tear and the crappy vet we had at the time recommended waiting for it to go entirely. It did finally go while we were in the middle of moving. We had the 'fishing line' surgery done because the new vet we went to recommended it since it was inexpensive, moderately effective, and didnt rule out doing the other surgeries in the future. When he operated he found that having waited a long time created extensive arthritis. Had we had the surgery done sooner rather than waiting for a full tear, it would have been nominal.
The extra load from having her favor the leg caused the other leg to go just a little over a year later. We had the bone surgery with a titanium plate done on that one. Minimal arthritis in the joint. The 2.5 month recovery was a good workout for me as I got to carry a 70lb dog up and down 3 flights of stairs the whole time.
About 5 months after the surgery she developed a couple of infections on the leg, which to me looked like they came from inside rather than something external like a bite or puncture. The vet disagreed, thinking it was a foxtail that went in at one site and came out the other. He operated extensively on the leg, found nothing, cleaned out the wound and closed it up. About 3 days after the antibiotic course was done, the sores opened up again.
We went back to the orthopedic surgeon, who suggested it may be a problem with the plate and he removed it. Once she recovered from the 3rd leg surgery in six months she's been fine.
I'm not sure how a titanium plate with stainless steel screws can cause an infection unless there was something wrong with the plate or how it was put in, but everyone said it was 'just one of those things that happens'.
She's now on a daily dose of doggie vioxx to combat the arthritis. We had a lot of trouble with the meds, going through 3 different ones. They all make her puke, although Deramaxx seems to cause her the least trouble. Unfortunately Deramaxx is about $600 a year.
My MIL had the same surgery on her chihuahua's rear leg. Took the same amount of time to recover. Didnt hear about any problems with the plate after that.