The first mould arthroplasty was made from glass in 1923 and was inserted in an ankylosed hip by Smith-Petersen at the Massachusetts General Hospital. Over the next decades, various other materials were used such as Vitallium (cobalt-chromium alloy), introduced in 1938 and polymethylmethacrylate (PMMA) by the Judet brothers in 1950. These prostheses are no longer in use. We report the case of a patient with a Judet acrylic prosthesis which has remained in place since 1951.