My Daughter In Law Who Has Had Hip And Knee

My daughter in law who has had hip and knee replacements has suddenly had a pain in her groin they say the hip joint is ok she cannot weight bare has been to dr. has had blood tests taken but no results yet had 2 injections for pain in her buttock but still no relief. so also has pain pills. really what is likely to cause such pain in groin all of a sudden she works and is trying to walk with 2 crutches. but said yesterday the pain is just as bad what is it likely to be. thanks