Hello and welcome to HCM
I don't think the pain and swelling is due to the implant in the knee unless you get any infection over their or injury
after the implantation
. Please let me know when implantation was done? and was you get any complication or not?
The other possibility for your symptoms might be Osteoarthritis
. Their is strong possibility for this because you age is above 40, You have two previous injury and get operated for that. Their are more risk in the patients for OA of Knee who had undergone surgery.
Please consult your doctor and get treated for the cause. Till that you can try Local application of gel, Crepe bandage, Hot fermentation and analgesic
. To reduce swelling keep the leg raised.
Best Wishes and have a speedy recovery