Suggest Treatment For Sacroiliac Joint Pain

I m trying to determine the best options for my 92 year old mother..she fell in the bathtub in November and now has severe pain which the Dr. diagnosed as sacroiliac..her Dr. is reluctant to advise due to her age..she is currently on Extra strength Tylenol which is not helping much..as she has also been diagnosed with kidney disease..which has been going on for over 20 years..any suggestions as to getting her mobile again?Her mental health is excellent and she is bound and determined to rid herself of the walker she now has to use. Two x-rays indicated no fractures.