First thing.

Drink 0.5oz of water for every lbs of body weight daily. Add a pinch of unprocessed sea salt per liter.

Many other things but if not doing this likely rest almost pointless.

cartilage of joint, partly made of water
lube in joint, largely made of water
water used to flush acid out of the joints
+much more

if you are dehydrated the body will scavenge water from areas of the body less important and use them for more important areas... joints are not high on the list of importance

Try that for a week, even though there are often many pieces to a puzzle I wouldn't be surprised if you saw (read felt) some great results.

If you lived out this way I would do some work on them - pay for results only