[Roentgenological manifestation of ossification of the posterior longitudinal ligament in the cervical spine causing severe spinal canal stenosis--a group comparison with and without marked spinal cord dysfunction].

Relationship between the degree of clinical symptoms and the lateral roentgenograms of the cervical OPLL causing severe spinal canal stenosis was studied among patients whose roentgenological minimum antero-posterior diameters of the available spinal canals were under 9mm. Lateral roentgenograms of 28 clinically mild patients were compared with those of 20 clinically severe patients. The type of ossification, the extent of OPLL, the narrowest level of the available spinal canal, and the minimum a-p diameter were not statistically significant parameters. The degree of canal stenosis at the 1cm cranial and 1cm caudal levels from the narrowest level, and the axial extent of canal stenosis around the narrowest level were less significantly in the group with mild symptoms than in the group with severe symptoms.