Human body is a fantastic but complicated bones puzzle. Some joints between two bones can be prone to different level of strain and depending of the forms of the bone those stresses can lead to cracks or worst to the bone fracture. Moreover the interface between the two bones is absolutely essential to avoid friction and its absence or its attrition will lead to serious discomfort and pain. The science of biomaterials and tissue engineering has allowed us to cope with those situations thanks to the works scientists who, by discovering replacement materials, developing new tools, and above all by working year after year to improve this kind of surgery to reach a state or quasi perfection, have given to many people a kind of second life. Thus, facing the problem of hip diseases like fracture of the femoral head or more usually the osteoarthrisis, artificial hip joint have been developed among the world throughout the 20th century and hence we can find nowadays several solutions available. This essay explains how artificial hip joints have appeared, why they have their actual shapes and compositions, and, eventually, which improvements are needed to obtain a flawless item.

[1] The osteoarthrisis, as shown below, is caused by a deterioration of the cartilage situated between the two bones. This problem mainly appeared among the elderly and often among the sportsman who are applying bog strain to their body and so to their articulation. By the deterioration of the cartilage, the friction coefficient increase and the bones get damaged. Hence the patient suffers of great pain and is unable to walk normally.

The main and first problem for researcher has been to find materials that can replace the cartilage, and/or the bones. Those materials must have different properties in order to fit well within our body: * Biocompatibility: the body have to accept the material * Bioactivity: interaction between the body and the material * [3]
Corrosion