Mechanical stamping: a cause of fatigue fracture

Failure analysis of a retrieved flexible intramedullary nail was performed by standard optical and scanning electron microscopy. Results show that the corrosion fatigue at the stamped label caused the nail fracture. The authors strongly recommend that the American Society for Testing of Materials standard F86-91 be modified to exclude mechanical stamping from the repertoire for labeling implants. Surgeons also must avoid using mechanically stamped hardware that will be subject to cyclic loads in vivo.