In the last two decades the performance of total hip replacements (THR) has constantly improved, thanks largely to advances in the field of material science and technology. Although contemporary devices are clinically very reliable, some problems still need to be addressed: the wear of ultra high molecular weight polyethylene components, the release of metal ions from metal-on-metal joints, the toughness of the ceramic cups and the possibility of squeaking for ceramic-on-ceramic couplings. All these drawbacks become particularly relevant in case of THR for young and active patients, when the life expectancy of the orthopedic device is very high and the possibility of mechanical shocks is not negligible.In the last few years an innovative ceramic-on-metal tribologic coupling has been introduced in clinical use. This novel configuration represents a very promising solution to all the aforementioned issues. Ceramic-on-metal offers both the strength points of ceramic and metal surfaces, and overcomes the limits of metal-on-metal and ceramic-on-ceramic bearings. For this reason, the ceramic-on-metal coupling has become the object of investigation for several laboratory studies and has been tested in clinical trials. This review study compares the scientific outcomes of the research on ceramic-on-metal bearings, confirming that this innovative articulation has the potential to be a suitable and attractive solution for young and active patients.
