Failure Analysis of a Commercially Pure Titanium Tibial Plate: The Drawbacks of a Non-preserved Fracture Surface

The importance of the study failures of surgical orthopedic implants increases more and more, due to two main factors: the increase in people’s longevity, as well as the greater exposure to different types of accidents. Just a consolidated knowledge of the modes and causes of these failures will lead to the development of implants to repeat the same type of failure. The purpose of this work is the failure analysis of a tibial plate manufactured with commercially pure (CP) titanium. Analytical techniques such as light optical microscopy and scanning electron microscopy (SEM) produced results that led to the conclusion that the plate was fractured by fatigue. Although the unsatisfactory quality of a significant part of the fracture surface has impaired the analysis, precluding the determination of the fracture origin site, it is believed that inadequate machining or even project errors, allowing the presence of sharp cavities on the holes surface where screws are inserted in the plate, acting as stress raisers, can be a contributing factor for the occurrence of fatigue fracture. The purpose of this work is the failure analysis of a tibial plate manufactured with commercially pure (CP) titanium. Analytical techniques such as light optical microscopy and scanning electron microscopy (SEM) produced results that led to the conclusion that the plate fractured by fatigue. Although the unsatisfactory quality of a significant part of the fracture surface has impaired the analysis, precluding the determination of the fracture origin site, it is believed that inadequate machining or even project errors, allowing the presence of sharp cavities on the surface of the holes where screws are inserted in the plate, acting as stress raisers, can be a contributing factor for the occurrence of fatigue fracture.