Performance of CF/PA12 composite femoral stems.

This study presents the microstructural and mechanical behavior of the CF/PA12 composite material developed as well as its biomechanical performance when used for the fabrication of femoral stems. The static tests were performed to evaluate the compressive and flexural modulus as well as the ultimate compressive and bending strength. It was found that CF/PA12 composite had bone-matching properties in the same order of magnitude as cortical bone in the femur. Density and void content measurements were also done to assess the consolidation quality. Dynamic fatigue testing was conducted on both CF/PA12 cylinders and femoral stems to evaluate the long term durability and mechanical reliability of the composite. Compression-compression cyclic loading was used at a frequency of 6 Hz with loads varying between 17 kN and 22 kN for the composite cylinders while a frequency of 10 Hz and load of 2300 N was employed for the femoral stems. Results indicate that the fatigue performance of CF/PA12 composite surpasses by far the required fatigue performance for total hip prosthesis (THP) stems. The overall performance of the CF/PA12 femoral stems confirms that this composite is an excellent candidate material for orthopedic applications such as THP stems.