An implant is a medical device manufactured to replace a missing biological structure, support a damaged biological structure, or enhance an existing biological structure. Medical implants are man-made devices, in contrast to a transplant, which is a transplanted biomedical tissue. The surface of implants that contact the body might be made of a biomedical material such as titanium, silicone or apatite depending on what is the most functional. In some cases implants contain electronics e.g. artificial pacemaker and cochlear implants. Some implants are bioactive, such as subcutaneous drug delivery devices in the form of implantable pills or drug-eluting stents.

Among the most common types of medical implants are the pins, rods, screws and plates used to anchor fractured bones while they heal.^{[citation needed]}

United State Classification

Medical devices are classified by the FDA under three different classes depending on the risks that the medical device may impose on the user. Class I devices are considered to be devices that pose the least amount of risk to the user and require the least amount of control. Class I devices include simple devices such as arm slings and hand held surgical instruments. Class II devices are considered to be devices that need more regulation than Class I devices and are required to under go specific requirements before FDA approval. Class II devices include x-ray systems and physiological monitors. Class III devices are medical devices that require the most regulatory controls since the device supports or sustains human life or may not be well tested. Class III devices include replacement heart valves and implanted cerebella stimulators. Many implants typically fall under Class II and Class III devices (Syring, 2003).

Medicine is the field of applied science and the art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness in human beings.

Contemporary medicine applies health science, biomedical research, and medical technology to diagnose and treat injury and disease, typically through medication or surgery, but also through therapies as diverse as psychotherapy, external splints & traction, prostheses, biologics, ionizing radiation and others. The word medicine is derived from the Latin ars medicina, meaning the art of healing.

Prehistoric medicine incorporated plants (herbalism), animal parts and minerals. In many cases these materials were used ritually as magical substances by priests, shamans, or medicine men. Well-known spiritual systems include animism (the notion of inanimate objects having spirits), spiritualism (an appeal to gods or communion with ancestor spirits); shamanism (the vesting of an individual with mystic powers); and divination (magically obtaining the truth). The field of medical anthropology examines the ways in which culture and society are organized around or impacted by issues of health, health care and related issues.