Abstract : Progress in implant design and surface properties have improved long-term survival of total hip prosthesis and lowered the incidence of dislocation. New materials, particularly ceramics and metals, decrease the risk for implant loosening because they induce less particle disease than polyethylene debris. These new materials have been submitted to simulator studies before being released for clinical use. They have been used since a sufficient amount of time in clinical practice to consider them as being part of our current armamentarium. They enable the orthopaedic surgeon to tailor the optimal hip prosthesis to each patient’s need, depending on his/ her bone stock, activity level and life expectancy. Disk prostheses and the general concept of non fusion surgery in spine surgery seems atractive, since intervertebral fusion carries a number of drawbacks, particularly at the level of adjacent segments. However, the documented follow-up of non-fusion spine surgery is at present insufficient to consider a widespread use of these new technologies. Their own possible complications are largely unknown and they do not replace bone fusion in the most clear-cut accepted indications for spine surgery. The use of disk prostheses should therefore be strictly limited according to present knowledge.