[Paget's disease, ankylosing vertebral hyperostosis and hyperostosis frontalis interna].

Ankylosing vertebral hyperostosis and internal frontal hyperostosis have a frequency of 5% and 8% respectively. In Paget's disease, these two disorders are found with a frequency of 40% and 19.1% respectively. This frequency is not due to chance. There exists a link between the 3 diseases. Ankylosing vertebral hyperostosis is thusa new pathological association in Paget's disease. It is even the most frequent of these associations. It seems Paget's disease induces hyperostosis and not the contrary. The authors suggest the theory that cortical and periostal hypervascularisation in pagetoid bone favour the development of these hyperostoses.