She can try going for a non invasive treatment, something that would not involve surgery but cure the disease effectively. My father is a recovering patient of Osteoarthritis. He was treatment by SPMF Therapy, where he had to lie down on an SPMF Machine for 1 hour everyday for 21 days. During those 21 days, except for that one hour on the machine, he could carry out normal activities at home. The patient does not need to stay in the hospital, one has to go only during the treatment time everyday. After 21 days, there was an improvement in his condition. Over the next few months, he started feeling even better. Before the treatment, he was unable to walk around the house too, now he is able to walk and carry out his usual chores and he takes a light walk outside too. He avoids over working his legs but he is much better now, the treatment worked really well for him.

You can visit their website and decide, http://sbfhealthcare.com

Since your grandmother iis sceptical about surgery, this treatment may be a good alternative for her.