The later part is me

Sorry to hear that - it's a pain eh!
I suppose it depends on the type of arthritis - I'm guessing from the wide spread that you have rheumatoid arthritis.
The laughable proper name for my type is - non-sero ( or sero-negative) which basically means the serum test shows NOTHING! But I nevertheless display inflammed and painful joints - hence the "itis" which means irritated - and it certainly irritates the hell out of me! Oh and BTW "arthro" stands for joint I think - as in arthropod.
So from this you may deduce that the entire array of medical science is at a COMPLETE LOSS as to what is actually causing my problems - but I really do have them and they've thought up a really cool sciencey name for it! This in iteself is quite good for doctors in general because they usually think you are mad if you complain about things they can't immediately see!
Osteoarthritis isn't the immune system attacking the body - it's wear and tear.
This is both right and wrong.
By my understanding, it's the immune system that decides what one's body is in shape and operation and attempts to keep things ticking along in the manner it found when it first switched on - so for ANYTHING bad to occur - something has gone wrong with it first. Thus a damaged joint is not perfectly repaired but left in a condition that causes further inflammation and this in turn encourages a vicious spiral of yet more eccentric repair.
The body will re-model the joint to some extent
The immune system has a copy of one's original DNA as a reference - when working properly it should rebuild any joint or organ perfectly - as it doesn't - there are imperfections in the system AND degenerative diseases of the system itself - we have NO IDEA what they are or how they work - hardly anyone is looking.
......so anti-inflammatories can slow down the progress of osteoarthritis a bit but the main reason for giving it is to control symptoms and relieve pain.
Quite so, but my symptoms overwhelming react to the amount of work / rest that I have as compared with the weather element - temperature is far more operative but affects me in both extremes of heat or cold.