First of all, you might have mistyped above regarding her Thyroid. Thyroid is a gland which is present in the neck and cannot be in tte knee. She might have Thyroid disease
if that is what you are trying to suggest? As far as the knee is concerned, she might have advanced knee disease
for which she has been advised Knee surgery
. However you should be very careful with regards to surgery, as you have already mentioned that she has been taking a lot of medicines. Do get a consultation from a good anaesthetist as to whether she is fit to undergo surgery. Your last question was about the leg cramps
, this can be due to a number of illnesses and you should get it checked. If you want more detailed opinion, please mention all the drugs she is taking right now and the diseases that she may have.
Wishing good health to you and your mother. Stay blessed.