Objective To evaluate the short-middle term clinical effects of the fixed platform stabilized prosthesis in the treatment of the elderly patients with rheumatoid arthritis(RA).Methods The clinical data of 53 cases elderly RA patients who were admitted to the People's Hospital of Liuzhou from January 2009 to January 2013 and were treated with fixed platform and stable prosthesis in 62 knees were retrospective analyzed.Results Fifty-three patients were followed up for 24.0-43.0 months with average (25 ± 2.1)months.At the last follow-up,the degree of knee motion was improved significantly compared with the preoperative((116.0±6.0) ° vs.(46.0±7.0)°),the difference was significant(t=35.323,P＜0.01).The HSS score was significantly improved compared with the preoperative ((85.3±7.6) points vs.(50.2±11.3)points),the difference was significant (t=4.002,P＜0.05).At the last follow-up,35 cases (66.0％) of excellent,11 cases (20.8％) of good,and 7 cases (13.2％) of normal.After the operation,all patients obtained obvious improvement in joint pain,swelling,dysfunction,deformity and so on.Conclusion The fixed platform stabilized prosthesis is simple,effective,and less postoperative complications,and it is a better choice for the elderly patients with high flexion activity.