How to prep for eventual TKR?

51 y.o. male, 5'11", 180 lbs. 3.5 years ago I had abrasive arthroplasty for a Gr IV chondral defect on the medial side. After a lengthy rehab I saw considerable benefit, but the knee has been getting progressively worse in recent months.

I saw a new ortho doc last month - new x-rays & MRI indicate that I've once again got a pretty worn-out knee. He's put me on a PT program that has helped somewhat, but he acknowleges that I'll need a TKR at some point, that the current P.T. regimen is a conservative treatment, and that we'll likely need to explore other options to delay TKR as long as possible.

I'm wondering what I might do to give myself the best shot as a successful, long-lasting TKR when the time comes. I know that losing ~10 lbs would help, and I intend to that. Additionally, maintaining muscle tone to the extent possible can only help.

What about dietary supplements like Sally Fields talks about to improve bone density? Does anyone know if they'd be beneficial for a future TKR candidate? My new ortho guy just kind of shrugged when I asked him, and said to just maintain a healthy diet.

A related side-note: The new ortho doc took several x-rays of the bad knee, including one from the front including my good knee. Upon his second review of that image (during MRI review) he noticed an unusual indication in the good leg's tibia, and sent me to an oncologist. The oncologist ordered an MRI, the MRI review described the growth as having "aggressive features" consistent with several types of cancer, but a biopsy/tumor removal/marrow transplant procedure last week proved it to be benign. Whew!!

Now I'm non-weight-bearing on crutches for 6 weeks waiting for the 1/4" access hole the oncologist drilled in my good leg's tibia to close, using my bad leg as my sole means of getting around. (no snickering!)

I asked him if supplements such as calcium or Vitamin D or anything else might help with the bone healing, and he also just said to eat a healthy diet.

I guess I'm just surprised at both doc's responses about supplements and dietary changes. Seems like I should at least try to eat a lot of bone, gristle and ligaments like you'd get in a bucket of KFC. (I wouldn't eat any of that greasy, salty chicken)

Gn