Eighty-eight bipolar Bateman hip endoprostheses for medial femoral neck fractures were implanted. The average age of the patients was 75 years. Intrahospital results proved the morbidity and mortality rates to be well within acceptable limits. Thirty patients were followed during periods of 12-74 months (median, 33 months). According to Charnley evaluation, mobility was excellent and very good in 20 patients (86%). Good function was present in 63% of patients. The majority of patients belonged to category C as defined by Charnley. Mild pain was present in 19 patients (63%); in only two cases, involving severe rheumatoid arthritis, pain was clearly related to sinkage. Radiographically, no visible protrusion or socket wear was present. Periarticular ossification occurred in 19 patients, but this did not impair function.