Failure investigation of a prematurely fractured stainless steel bone fixation implant

Metallic orthopedic fixation implants are devices which are used to accelerate the healing process of bones after fractures. Fixation implants may fail within short period of time because of the fatigue mechanism when they are improperly installed and subjected to cyclic loads. Since replacing failed implant places emotional, physiological, and economic burden on the patient, a failure analysis can be carried out to understand causes and the mechanisms of the implant fracture that would help to develop better implant devices.In this study, an orthopedic fixation implant (compression plate) made of 316L stainless steel that failed prematurely was examined for determining the basic mechanism/s responsible for the fracture. Fixation implant that was mounted to a broken right femur of a 22-year-old male patient was prematurely failed by fracture after seven months of installation. Failed implant was examined visually and metallographically to analyze the failure mechanism and its cause(s). The results of the surface topology showed that fixation implant was failed due to low energy fracture behavior of fatigue and cleavage mechanism due to post operational malpractice without any deterioration by corrosion.