ABSTRACT
I. CEMENTED ACETABULAR COMPONENTS A. Polymethylmethacrylate Cemented acetabular components are held in place by polymethylmethacrylate (PMMA). Bone cement comprises powder and liquid components. The powder is made up of granules of prepolymerized methacrylate with 2% benzoyl peroxide. The liquid is methylmethacrylate monomer with 1-2% dimethyl paratoluidine and a very small amount of a polymerizing inhibitor, such as hydroxyquinone. On mixing the powder and liquid, a growing chain of methacrylate molecules forms. This material, in various proprietary forms, has in essence remained unchanged for more than 20 years. Various efforts, over the years, to improve bone cement have failed, some dramatically.
