[Value of radiologic evidence for the diagnosis of the loosening of cement-fixed total prostheses of the hip joint].

A diagnosis of loosening of cement-anchored alloarthroplasties of the hip joint is mainly based on morphological x-ray film findings. Definite signs of loosening, however, are represented by drastic positional changes or ruptures of the implant only. All other radiological signs, such as concentric or defined osseous absorptions (bordering), damage of the osseous implant bed with slight positional change, or reactive ossifications of the osseous prosthesis bed, as well as disruption of the bone cement alone, are useful only as pointers or as latent signs of loosening. It is only when several of these signs appear together in a typical constellation, that one can safely concluded that loosening has actually occurred.