Cherub, I had a TKR in Dec last year. The new joint is solid as a rock but I, too, still have a lot of painful swelling & inflammation over a year later. It might interest you to know that my surgeon is convinced this swelling is caused by peroneal nerve entrapment and is recommending a nerve decompression procedure. Reading your post made me wonder if something similar is happening to you. This large nerve branches into two further down the shin - one branch is called the deep peroneal nerve and the other branch is called the superficial peroneal nerve. By palpating certain points on my lower leg (including the front of my ankle & my knee) there was aching nerve pain. He couldn't even palpate the outer side of the knee, it is far too sensitive.
I had a lateral release at the same time as my TKR. Crucially, my patella had been badly positioned directly on top of the peroneal nerve. He thinks that the nerve entrapment further down the leg combined with the fact I was chopped about a bit during the process of having my kneecap repositioned, has not only slowed down soft tissue healing but has actually aggravated the knee pain, causing the swelling.
I have other symptoms too. A bit of a numb big toe. Also I get foot cramps sometimes AND when trying to do my ankle circling exercise, it's much harder to do on the operated leg. These are all areas touched by the peroneal nerve. Basically the sheath surrounding the nerves is tight & pressing on the nerves, causing a chain reaction aggravation up into my knee.
The op I'm having involves the widening of the nerve sheath, using two incisions, it is done as day surgery under general anaesthetic & I'm told it has a very good success rate. My surgeon feels that this op combined with being able to do more exercise (I empathise with you regarding the pain - it holds you back from exercising if all it does is increase swelling) will do the trick. I am very relieved to think there might be a solution to my continuing pain & have an excellent surgeon. When you mentioned the front of your ankle hurting, it rang bells for me. It may be worth mentioning this to your surgeon next time you see him/her? Good luck to you, & let me know how you get on