hello arbito mate .. speaking as an ex nurse.. your actually probably better not having a knee replacement .. the scarring and adhesions you’ll incur through multiple ops will only aggrevate the tissue and muscles.. you actually dont need a knee cap like a few other organs and bones in the human body, and might find that just strengthening your upper thigh muscles and ligaments around the knee area will work better .. my sister in law had a car crash and ended up having her knee cap breaking through her skin (compound fracture) they took it out.. offered her a plastic one.. we went online to check it out… for the last 6 years she’s been without a knee cap and doesnt have to worry about it being either rejected by her body, nor infection .. check it out. it might not be what you need but i thik every little bit of info helps xx best of luck hun hope everything goes well xx