The Utility of MARS MRI in Patients with Metal-on-Metal Bearings

Abstract

Listen

Translate article

Metal-on-metal bearings for total hip arthroplasty have a long history of use that dates back to the introduction of the McKee-Farrar prosthesis in the 1960s. Metal-on-metal bearings ultimately fell out of favor because of the excellent clinical results of the Charnley low-friction arthroplasty concept, which employed metal-on-UHMWPE (ultra-high molecular weight polyethylene) bearing surfaces. However, the use of metal-on-metal bearings was revisited in the 1990s as polyethylene-associated periprosthetic osteolysis emerged as a major clinical problem limiting the longevity of hip reconstructions in high-demand patient populations. Within the last decade, numerous metal-on-metal designs for both total hip arthroplasty and hip resurfacing arthroplasty have been introduced into the marketplace. However, over the last several years it has become evident that contemporary metal-on-metal bearings are not immune to some of the problems, including periprosthetic osteolysis, that have plagued other bearing surface combinations. In addition, investigators described a distinct histological pattern, termed “aseptic lymphocyte-dominated vasculitis-associated lesion” (ALVAL), that was associated with symptomatic metal-on-metal bearings. More recently, investigators described local soft-tissue reactions termed “pseudotumors” in association with symptomatic metal-on-metal devices. Initially, studies of adverse local tissue reactions (including osteolysis, ALVAL, and pseudotumors) in retrospective studies of metal-on-metal implants did not indicate the prevalence. However, case-control studies and registries began to document that certain metal-on-metal bearing designs were associated with an unacceptably high failure rate, leading to high-profile device recalls that captured the attention of the worldwide media. In some cases, the adverse local tissue response …