I have found information that states with osteoporosis the spine is impacted first (people in their 60’s , the hips become impacted later in life, more in the 80’s. I think it probably has to do with the fact that the mesenchymal area of the vertebrae of the spine is where the differentiation of cells is determined ie…how many and what will become osteoclasts (bone eaters) versus osteoblasts (bone builders). A balance needs to be established for building and keeping bone at good levels. Sometimes it’s also my understanding that within the mesenchyme the cells may become fat cells , not bone related cells at all.