Suggest Remedies For Chronic Knee Pain

hi,
my mother having ankle pain and she is feeling with pain from last 4 years,and we consulted many doctors and taken different kind of medicines but we haven't seen any cure...she got it when she was felt with fever ..4 yrs back...from that time to till she is feeling with pain,on the spot of ankle getting blow and if she takes any medicine then immediately will go off....but again after 2 days it will come back with pain,so plz suggest me what is th e solution for it,which is best hospital/doctor/consultant for it?