Yes,my Wife Had A Cortizone Shot In Her Leftt Knee

yes,my wife had a cortizone shot in her leftt knee due to swelling and Was told either knee replacement or cortizone.she is 65 and has never had probs with knee till this summer.it had been operated on when she was a teen.pain initially started in back of knee.she is now having similar pain in back of right knee.a)would a reaction to shot perhaps cause low back pain that has confined her pretty much to recliner for last couple weeks ? b) she is very similar in gene/personality makeup to her deceast dad who had a bout with intestinal cancer at a little later age and he also was dignosed with alzheimers,might this be a more probable diagnosis ? i will not hold anyone to their answers,only looking for direction in which she may ask ?'s to her own primary care Dr. Thank You !!