Metallographic examinations of retrieved intramedullary bone pins and bone screws from the human body
✍ Scribed by Gray, R. J.
- Publisher
- John Wiley and Sons
- Year
- 1974
- Tongue
- English
- Weight
- 825 KB
- Volume
- 8
- Category
- Article
- ISSN
- 0021-9304
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✦ Synopsis
Abstract
Substantial improvements have been made by the surgical manufacturing industry in the development of implants and by the orthopedic surgeon in the use of prosthetic appliances. In spite of these advancements, some prosthetic devices completely fail of do not provide satisfactory performance. Hostile environmental conditions of the human body are highly influential in limiting the service life of the implants, so the material selection and the design and fabrication must be made with extreme care. Examinations we have made of intramedullary pins retrieved from femurs reveal examples of fretting and/or crevice corrosion and in‐service failures that nucleated in microscopic surface gouges. Self‐tapping screws, essential for securing bone implants, failed due to fractures originating in the thread roots. Failures by merely exceeding the ultimate strength of the material and by the more involved process of stress corrosion cracking are shown.
An evaluation laboratory for failure analyses of prostheses is recommended.