The mineral content of 42 normal and 19 vertebrae with metastases obtained at postmortem was determined by a dual energy method and this was related to their ability to fracture. In the normal vertebrae, this relationship was expressed in the form of a logarithmic function. Amongst vertebrae with osteolytic lesions, liability to fracture increased more rapidly than mineral loss. Vertebrae with osteoblastic metastases showed increased mineral concentration with an increased liability to fracture as compared with normal vertebrae.
