Aseptic loosening in total hip implants: the role of polyethylene wear debris.

Radiologic and routine histologic examinations, transmission electron microscopy and scanning electron microscopy were carried out on membranes retrieved from the following hip implant prostheses: loose cemented metal-on-polyethylene, resorptive cysts around fixed cemented metal-on-polyethylene, cemented without polyethylene (Thompson), noncemented without polyethylene (Moore), loose ceramic-on-ceramic and loose noncemented metal-on-polyethylene. From histologic analysis the most common factor in the membranes reviewed, in terms of production of multinucleated giant cells, is the presence of polyethylene wear debris. Neither loosening of the implant nor the presence or absence of bone cement produces such cells within the membrane.