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Although surgical techniques, materials, and prosthetic components have substantially decreased the rate of loosening in total hip replacements, osteolysis has continued to be one of the major factors compromising results.
It has become clear that the production of polyethylene wear debris is not only an important issue in the fate of prostheses, but is one of the most important issues in determining the longevity of total joint replacements.
Charnley, in 1968, identified aggressive osteolysis occurring around some of the cemented components. He believed that these lesions were secondary to a chronic infection. Since that time, many studies have established the association of the foreign body reaction with the development of osteolysis in the absence of infection.
Early in the 1980s, it was believed thai the main factor responsible for the production of osteolysis was the methylmethacrylate bone cement used to secure the components to the bone. Abnormal tissue reaction to the "cement" was blamed for the development of osteolysis (cement disease). This ultimately led to "cementless" implants, which have become very popular. However, it has been recognized that osteolysis is related more to the polyethylene wear than to the type of fixation. There are several reports illustrating the relentless progression around cementless components. These reports emphasize the need to understand the mechanisms involved in the production of osteolysis, the need to develop preventive measures, and the importance of early recognition and intervention.
The authors in this repon demonstrate a case of massive acetabular osteolysis and make recommendations in regard to its early recognition and timely surgical correction.
Arnold T Berman, MD
PATHOGENESIS
Mechanical friction between the metal and polyethylene components leads to the development of polyethylene debris. The debris incites a foreign body granulomatous reaction that induces localized bone résorption, similar...