Medical implants fall under the larger category of medical devices, which are defined as products used for medical purposes in patients, in diagnosis and/or treatment. There are three classes of devices that are controlled by the Food and Drug Administration (FDA). Class I devices present the lowest safety risk and are only subject to general controls; Class II devices require general and special controls involving labeling requirements, mandatory performance standards and adequate surveillance; Class III devices must have the same general and special controls as Class I and II devices, and undergo scientific review. Class III is the most scientifically rigorous classification of medical devices and encompasses most of the orthopedic implants on the market today. In this paper, different categories of orthopedic implants will be discussed, including the development of artificial anterior cruciate ligament (ACL) grafts and FDA approval of alumina ceramic-on-ceramic (COC) total hip prostheses.