Can Knee Replacement Surgery Be Done If X-ray Shows Degenerative Changes?

Hi, may I answer your health queries right now ? Please type your query here...My mom is 85 and in good health. She line dances twice a week, drives, and goes to the gym three times per week. She had right meniscus surgery 12 years ago. Last 6 months lots of right knee pain, 3 cortisone injections. X rays show lots of wear and tear. Is she still a candidate for knee replacement surgery?