Materials Used in Orthopaedic Implants

Importance of Materials

As you go about your daily activities, an implant may encounter mechanical forces that tend to push on it, pull on it, bend it, scrape it, or cause its parts to rub together. These forces can cause the implant to break or wear out over time.

It is also subjected to the many natural chemicals inside your body. Although normal, some of these chemicals may tend to corrode some materials. In order for an implant to perform under these conditions, it must be made from materials that can withstand these forces and chemicals.

Whether an implant is designed to replace a joint, or help repair a fracture, several physical and biological characteristics are important when selecting the material for the implant. For example, an implant must be sufficiently strong, flexible, and resistant to wear. But that doesn’t mean the strongest material, or the most flexible material, is the best material.

The ideal implant material would have physical characteristics that match those of the bone it is replacing or reinforcing. After all, orthopaedic implants are attached to your bones, and they must work with your bones to restore function. This usually requires a balance of physical characteristics. Your bones, for example, are strong but flexible. This combination helps them withstand forces as high as several times your weight without breaking.

Obviously, physical characteristics are important to orthopaedic materials; but biological characteristics are just as important. When we talk about biological characteristics, we mean the biological effect the material has on the body, as well as the effect the body has on the material.