【Abstract】 Objective To explore the flexibil ity and rel iabil ity of cementless total knee arthroplasty (TKA) without patellareplacement through a retrospective study of the mid-term therapeutic effect of the treatment of the patients. Methods FromJune 1997 to March 2000, a consecutive series of 152 (152 knees) cementless TKA performed in Hessing-Stiftung was studied. Among them, there were 63 males and 89 females, with 70 left knees and 82 right knees. Their ages ranged from 51 years to 72 years, with an average of 59 years. There were 146 cases of osteoarthritis and 6 cases of traumatic arthritis. The course of the disease lasted for 1.0 years to 3.5 years. The EFK prostheses of German Plus company were used in all the cases. The HSS score before the operation was 41.5 ± 12.3, and the average range of motion was 55º (ranging from 30º to 90º). Results Five patients underwent anterior knee pain, and the pain was released after the appropriate treatment. No deep infection happened in all cases. A total of 145 patients (145 knees) were followed up for 5 years to 8 years. The HSS score was 87.5 ± 8.2 at the end of the follow-up, showing significant difference (P lt; 0.05). The average range of motion was 95º (ranging from 90º to 110º). Partial radiolucencies occurred at the tibia side in 18knees 3 to 6 months after the operation. Among them, the width was less than 2 mm in 15 knees without symptom, and more than 2 mm in 3 knees. There were 2 of the 3 knees which were revised at the tibia side because of the aseptic loosing, while 1 patient had only mild pain in the knee during the follow-up, with no sign of loosing. Conclusion The mid-term effect of cementless TKA is satisfactory. The ingrowth of femur and tibial bones is rel iable. The early stage migration of the component is the main reason of loosing. Satisfying outcomes can also be achieved without patella replacement during TKA.