Syndesmo-odontoid joint and calcium pyrophosphate dihydrate deposition disease (CPPD).

Twenty-seven patients with definite or probable CPPS have been investigated with systematic frontal and lateral tomograms of the cervicooccipital region. In 12 cases there were calcifications of the syndesmo-odontoid region. These calcifications are of two different types: linear calcifications (5 cases) and mottled calcifications (7 cases). The anatomic location of these calcifications is the transverse ligament or other structures of the syndesmo-odontoid joint. Although this type of calcification has already been described in other rheumatic diseases, it must lead to search for CPPD in the usual locations.