For orthopedic devices, such as spinal implants, knee implants, and hip implants, the verification protocols are usually defined by ASTM standards which govern how these devices must be tested. For each type of device, FDA provides guidance on the modes of testing which should be conducted on the device, and ASTM standards dictate how each of these tests must be performed. Any deviations from the standard must be stated and rationalized. The acceptance criteria that the device must meet in order to be deemed acceptable is up to each individual company. Most companies state that the performance of their device to be tested must be equal to or greater than that of a predicate device. Another strategy is to use clinical data from white papers showing the physiological forces that the particular device could be exposed to, and using this data as your acceptance criteria.