Orthopedic implants can be quite complex, and the materials used to make them, called biomaterials, are highly developed. New materials require extensive testing before they can be used in an orthopedic implant. The materials most commonly used have a long history of clinical use with great success.
There are many different biomaterials, and there’s no single biomaterial that’s best for all implants and all patients. The specific requirements of an implant’s material varies depending on how the implant is designed to be used.
An orthopedic implant has a challenging job. As you go about your daily activities, an implant will encounter mechanical forces that push on it, pull on it, bend it, scrape it, and wear against it. These forces can cause parts of the implant to break or wear out over time. The implant is also exposed to the many natural chemicals inside the human body. Some of these chemicals may be corrosive to some materials. In order for an implant to perform under these conditions, it should be designed to address all of these factors. Remember, however, that medical implants are artificial and not as strong as healthy, natural bone; implants can wear out, loosen, or break, and it is important to discuss these potential risks with your surgeon.
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 will be the best to use.
The ideal implant material should have physical characteristics that match those of the bone it’s replacing or reinforcing. After all, orthopedic 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.
Obviously, physical characteristics are important to orthopedic 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.
If you’re considering joint replacement, make sure to discuss your options with your doctor. They can advise which products are right for your specific case.