Ionogran in revision arthroplasty

Glass ionomer cement (Ionocem) was developed for use in bone surgery and is reported to be notably biocompatible. Between 1991 and 1994 we performed r evision operations for aseptic loosening of arthroplasties of the hip on 45 patients using this material in its granulate form (Ionogran) mixed with h omologous bone as a bone substitute. Of these 45 patients, 42 were followed up for a mean of 42 months, Early reloosening of the acetabular component has occurred in ten after a mean of 30 months. Histological examination sho wed large deposits of aluminium in the adjacent connective tissue and bone, Osteoblastic function and hone mineralisation were clearly inhibited. The serum levels of aluminium were also increased. The toxic damage at the bone interface caused by high local levels of aluminium must be seen as an impo rtant factor in the high rate of early reloosening, Our findings cast doubt on the biocompatibility of this material and we do not recommend continuat ion of its further use in orthopaedic surgery.