Loosening-proof of the femoral component stem
Grant-in-Aid for Scientific Research (C).
|Research Institution||Yamagata University|
NASU Yasuo Yamagata University, Faculty of Engineering, Professor, 工学部, 教授 (50007001)
|Project Fiscal Year
1990 – 1991
Completed(Fiscal Year 1991)
|Budget Amount *help
¥1,900,000 (Direct Cost : ¥1,900,000)
Fiscal Year 1991 : ¥400,000 (Direct Cost : ¥400,000)
Fiscal Year 1990 : ¥1,500,000 (Direct Cost : ¥1,500,000)
|Keywords||Femoral prosthesis / Bone cement / Loosening-proof / Testing jig / Failure of stem / cement interface / cement mantle strain / Acoustic emission / Axial subsidence of stem / 人工股関節 / 骨セメント / 耐緩み特性 / 骨代替冶具 / ステム / セメント界面破壊 / セメントマントルひずみ / アコ-スティックエミッション / ステムの軸方向沈み込み / ステムーセメント界面破壊 / 骨セメントマントル内ひずみ / ステム軸方向沈込み|
In order to evaluate the loosening-proof of femoral component stem quickly without a human femur, a substitute jig for human femur(testing jig)was simply designed from the data of the size of the human femurs. The cement mantle strain analysis was carried out on the simplified model by using FEM. Outer shape of the testing jig was determined in the same cement equivalent strain as one with the femur model.
Several stem (made of SUS316L steel, CoCrMo alloy and Ti-6Al-4V alloy) were tested. The femoral stems were implanted into the testing jig and were subjected to the cyclic loading (-500N- -2000N) at a frequency of 1- 5Hz at a room temperature. The cement mantle strain and the micromotion (bi defined as the axial motion between the implant and the testing jig due to applied axial load) were measured. In addition, the acoustic emissions from the implanted stem component were analyzed. According to the laser displacement sensor (LDS) record at the minimum loading(-500N), axial subsidence,
which was the amount of unrecovered micromotion at each loading cycle, was determined.
The stem had subsidence rate about 30- 180/mum/10000C. T-28(4045-02), with trapezoidal cross-section)stem had the much greater axial subsidence rate than others. The stem size as well as surface morphology(such as surface roughness)is effective in enhancing loosening-proof. The axial cement strain data by using a substitute jig for femur agrees approximately with others experimental data by using a cadaver femur.
The AE were detected from T-28(4045-02)and TR-28(4045-16)stems. Both stems were made of SUS316L stool and polished. The AE from the stems had a special characteristics of 10K Hz- 20KHz. In order to investigate the cause of these AE, the push-out test was carried out. The AE from the push-out test was similar to the AE from the stems. The comparison of the AE analyzed data suggests that the both AE from T-28(4045-02)and TR-28(4045-16)stems might be produced in the stem/cement interface failure and micro stick-slip.
Research Output (3results)