- Fratigue Fracture:
    - frx or break or a metal caused by repetitive applications of loads in between the fatigue limit and the Yield Strength;

- Fatigue Limit:
    - load that a metal can endure indefinitely without bending or breaking when subjected to cyclic bending;

- Fatigue Strength:
    - maximum load that metal can withstand w/o fracturing when subjected to 10 million cyclic loads;
    - it is sometimes referred to as the endurance limit;
    - this is probably the most important characteristic of a femoral stem because it determines ability of device to withstand long term loading without fatigue fracture