The authors conducted two studies to demonstrate the presence of a relationship between osteoporosis and arthrosis: the first study was experimental involving thirty femoral heads removed during hip arthroplasty, and the second was a clinical study conducted on forty patients with coxarthrosis. The results obtained confirm how the presence of one of the two pathologies may prevent or delay occurrence of the other, and on this basis the authors review the literature. Finally, also taking into account the interpretations of other authors, possible hypotheses on the inverse relationship that links the two pathologies are proposed