Choosing an uncemented femoral prosthesis means first choosing a concept and to be effective, an operator has to have access to all the information that will allow them to reach the desired goals. This is the first step to be made.The quality of a surgical procedure does not depend on the manual skills of the surgeon performing it, but on how he has prepared and performed the operation "virtually" before actually performing it. This is the second step.An operating technique must be adapted to the chosen concept and the purpose of every surgical procedure must be clearly formulated and understood by the operator. This is the third step.Every surgeon has to have a reliable and rigorous radiological method of analysis for evaluating overall results and which suggests ways of improving results.