Device for holding the pelvis comprising - two components (40, 80), each component comprising a substantially horizontal part (44, 84) and a part directed upwards (42, 82), the substantially horizontal parts of the two components being able to slide one relative to the other in order to adjust the said device - a clamping system (60) for clamping the said two components which collaborates with the substantially horizontal part of each component - two means (30) for clamping the said device to the said pelvis, each means collaborating with the upwardly directed part of each component - the substantially horizontal overall cross section of the said device being equal to each cross section of the substantially upwardly directed parts. The system proposed is simple to use because it is made up of a minimum number of components it minimizes the risk of puncturing the pelvis thanks to a system that limits the clamping force and the presence of a grip washer (7) with studs (702). In addition it is radio-transparent and in a preferred alternative form is a single-use item.
