I agree. It could be that you had this condition, to a lesser degree before surgery and the Anaesthetic made it worse. I can't think of any other reason unless you severely reacted to a particular medication.
If you have a cardiologist, he or she should have explained things to you. I think you are going to have to pursue answers quite aggressively, both by quizzing your cardio and be doing a lot of reading.
No an EKG was not performd before surgery and yes I do have a cardiologist
Yes the reason I asked is that if rbbb or lbbb exists before general anaesthetic, it has happened where the anaesthesia has increased the severity, even moved it to full block. In some cases, after a few months, it has reverted back.
As ed says, you should have had an EKG before your surgery, because this is standard procedure before any surgery involving anesthesia. Was one done? That is the first and most important question for you to ask whatever doctor you are seeing.
Second, you should now be under the regular care of a cardiologist, one who will keep an eye on you for years, to say nothing of answering your questions. Do you have a cardiologist? If not, you should get a referral to one about now.
Third, there are a number of causes of third degree heart block. You can read about some of them here:
http://www.chop.edu/service/cardiac-center/heart-conditions/heart-block.html
I hope you get answers soon--and continued good care by a qualitified specialist.
Third
Did you have an ECG before the procedure on your knee?