A metal-on-ceramic total hip replacement uses metal for one side of the hip joint prosthesis and ceramic for the other. The metal forms the femoral (thigh-side) component and the ceramic surface is on the acetabular (hip socket) side. The potential advantage of a ceramic component over a plastic (polyethylene) component is that it is harder, so it is believed to have less particle wear over time. This results in less local inflammation and a decreased risk of aseptic loosening (loosening of the prosthesis in the absence of infection). The advantage of a ceramic component over a metal component is there is less metal ion release over time -potentially decreasing local inflammation and eliminating any potential side effects of elevated metal ions in the blood stream. Metal-on-ceramic total hip replacements may be considered in younger patients because there is less risk of implant loosening and wear over time, potentially increasing the lifespan of the hip replacement.
Although there are advantages, using a ceramic material can be problematic because ceramic is hard and brittle. However, improvements have been made on the composition of ceramic prostheses that make them less likely to break. Some metal-on-ceramic implants may cause a “creaking” noise with certain movements. This noise can be very annoying to patients.