Intermediate bipolar acetabular system These intermediate bipolar acetabular cups consist of a polyethylene liner made of UHMWPE in compliance with ISO 5834-2 and a metal back manufactured from stainless steel (ISO 5832-1). The outer metallic surface treatment has been prepared with the greatest care since it is placed in direct contact with the pelvic acetabulum. The polyethylene liner is interdependent from the metal back. This bipolar acetabular cup is indicated in femoral head or neck trauma without destruction of the acetabulum. CHIBF intermediate bipolar cups are available to match modular femoral heads of 22.2 mm (sizes 39 to 57 mm) and 28 mm diameter (sizes 45 to 59 mm).