Corrosion-Fatigue Performance of Stainless Steel Hip Nails—Jewett Type
SourceCriteria and standards for the corrosion-fatigue performance of orthopedic fixation devices are reviewed in general and with specific reference to hip nails. The development and application of a simulated, in-vitro, performance test for a fixation device are demonstrated for the Jewett combination nail plate. Corrosion-fatigue results obtained both in air and in Ringer's solution and failure modes are presented and discussed with regard to the Jewett device. The importance of fatigue crack initiation on the fatigue life of fixation devices is demonstrated, and the mechanisms and locations of fatigue crack initiation are documented in detail. This study has shown that initiation is dependent not only on the location of maximum stress but also on the environment and on the incidence of fretting or fretting corrosion. Minor surface scratches appear to have no effect on fatigue crack initiation.