Acetabulumpfanne

Acetabulumpfanne, commonly referred to as the acetabular cup, is the hemispherical component of a total hip arthroplasty that is implanted into the acetabulum to form the socket of the artificial hip joint. Along with the femoral stem and head, the cup enables articulation and stable hip motion. The term combines acetabulum, the pelvic socket, with pfanne, a German term for pan or cup.

Construction and materials vary by design. Modern cups are metal shells, typically made of titanium or cobalt–chromium alloys. They may be cemented into the acetabulum or implanted as a cementless, press-fit component with a porous or textured outer surface to encourage bone ingrowth. A liner, made from high-density polyethylene, ceramic, or metal, is fixed inside the shell and provides the articulating surface for the femoral head. Bearing combinations include ceramic-on-ceramic, metal-on-polyethylene, and ceramic-on-polyethylene, among others. Some systems use modular liners to allow intraoperative customization of offset and version.

Indications and procedure. The acetabular cup is placed during total hip arthroplasty for end-stage hip diseases such as osteoarthritis, rheumatoid arthritis, avascular necrosis, or trauma with joint destruction. After preparing the acetabulum with reaming to create a congruent socket, the cup is positioned with careful attention to orientation, commonly toward about 40 to 45 degrees of abduction and 15 to 25 degrees of anteversion. Supplemental fixation with screws may be used in cementless designs.

Outcomes and considerations. Longevity depends on bearing surface, fixation, and patient factors; common long-term issues include loosening, wear of the liner, dislocation, and infection, potentially requiring revision. The acetabular cup remains a central element of hip replacement success and continues to evolve with advances in materials and fixation techniques.