[Loosening of a total hip arthroplasty due to metastasis]

A case report of a metastatic caused loosening of a total hip arthroplasty one year after primary implantation is presented. A primary cancer was unknown at surgery. Due to suspected low-grade infection, a revision surgery was performed and the diagnosis of a metastatically caused loosening could be made. A bronchial carcinoma was identified as primary cancer. In spite of the rare incidence of the described metastatic loosening, the significance of a differential diagnostic strategy and the importance of a histological examination in revision surgery is depicted.