ASPECTS RADIOLOGIQUES DU CRANE DANS L'HYPEROSTOSE VERTEBRALE

Skull radiographs were studied in patients with Forestiers's disease (FD)(57 patients, mean age 67.3, 25 males). The results were compared to a control series of subjects with normal spine radiographs (54 controls, mean age 71.2, 29 males). Four kinds of radiographic findings are found in relationship with FD: (a) hyperostosis frontalis interna (45.6% in FD versus 13% in controls): (b) ossification of the Gruber's ligament (28% versus 9.2%): (c) Calcification of the falx cerebri (42% versus 18.5%): (d) ossification of the insertion of the posterior longitudinal ligament of the cervical spine (42.8% versus 7.4%). These findings are non-specific but their high frequency in FD suggests the occurrence of a diffuse ossification process. Previous studies of the limb joints also pointed out this feature. The pathogenesis of the skull changes probably involves an ossification process of the membranous type with osseous metaplasia of the dura mater. The basic mechanism of this ossification of FD remains unknown.