Can you please explain what the "knots" in your feet are?

Are they swellings at the joints? On the tendons...? or just tight feelings?

I am getting an impression you have an inflammatory thing going on since you had that synovitis in you knee.

It may be a combo of things with you. Inflammation, left over issues from the surgery, etc. What injections did you get in the feet? What was in them?

Have you ever been tested for gout (uric acid)? Or pseudogout (calcium)?

I think you have more than one thing happening and it is confusing your issues.

For inflammation you will need much more fish oil. More like 3 a day. I'd also stop taking extra B6 if you are taking a multiB complex.

I'd also make sure your magnesium is NOT OXIDE form.

And get tested for Vit D3. ASAP and take appropriate doses determined by your test results. Do not accept the RX 50,000 that doctors write for...as it doesn't work well.
Figure 1000IU D3 for every 10 points you want to raise based on your blood work. Proper Vit D levels will prevent upper respiratory infections and calm the immune system.

There are anti-inflammatory antioxidants. The most affordable one that works is grapeseed extract. At least 200mg a day of this may help with arthritis. There are others... enhanced absorption curcumin and also astaxanthin. Eat as much antioxidant containing foods that you can. Blueberries, strawberries etc.

People very low in Omega-3's often have inflammatory problems, poor stomach lining and poor lining of the lungs. (this latter issue results in many infections and pneumonias.)
Our Vitamin forum has EFA information and a Vit D thread. Both can help you, I believe.

If your magnesium is Oxide...then change that to a chelate that is better absorbed. Omega-3s need magnesium to be metabolized properly.

I think you have some very complex issues, and they are not going to go away quickly. So you have to be patient, and try to read the posts here that we have amassed over the years.