The standard implant is available in 6 right sizes and 6 left sizes, with and without collar. Standard OPALE presents a fixed neck length of 36.5mm whatever is the size of the implant. Since 2005, OPALE XS has been re-inventing the concept of the anatomic implant by freeing itself from its distal tip, but by preserving the essential elements of the success of its standard version: implant designed for a purely metaphyseal anchoring metaphysis length from 75 to 91mm reduction of the length equivalent to 40mm compared with the standard version conventionnal cervical height and angle of resection of 45 ° femoral preparation in the axis of the femur with compacting rasps compatible with the anterior, anterolateral and posterior surgical approaches homothetic neck length micro-grooved and short 12/14 taper suitable with metal and ceramic heads