There is no reason why you should have any problems with your knee surgery because of your encapulated breast.
Encapsulation of knee
It's my opinion that all prostheses whether breast or made of metal or ceramics will have some type of scar around them. Because a knee prosthesis is of a firmer or metal like consistency there's nothing for the capsule to squeeze against. Therefore, even if there is a capsule it's of no consequence. I would have no problem recommending that you have knee surgery. Good luck.
Repetitive Capsular Contracture
Your recurrent capsular contractures are not an indicator of a problem with your body, and you shouldn't be concerned about your orthopedic procedure.
Best of luck!
Encapsulation indicator of touble with knee surgery
Encapsulation of your breasts has to do with free silicone material; please note that this should not affect your knee surgery in any way.
That's a very good question, and one I've wondered about over the years as well. I'm not sure I've ever seen convincing evidence that problems with another implantable device (joint replacements, ports, pacemakers, shunts, etc.) correlate with breast implant capsules. We don't know for certain what causes problems w/ breast implant capsules (contracture), although there are several leading theories. It probably is more related to bacterial infection or device-specific interactions w/ our bodies. I hope that helps a bit. Best wishes.