[Histopathological studies of the osteophytes and ossification of the posterior longitudinal ligament (OPLL) in the cervical spine].

To obtain information on ossification around the vertebral body of the cervical spine, we carried out histopathological investigation on 30 autopsy cases. The results were as follows; Intervertebral discs were untouched, anterior osteophytes developed along the anterior longitudinal ligament and they corresponded to anterior spur in spondylosis deformans. Posterior osteophytes around the posterior edges of vertebral body resulted in intervertebral insufficiency, and corresponded to hypertrophic spur in osteochondrosis. Histopathological findings of hyperostotic anterior osteophytes were similar to anterior osteophytes, but in the former there were advanced osteophyte formations. In OPLL of the segmental type, intervertebral discs were degenerated, and ossified mass did not involve the posterior longitudinal ligament of the parts of discs. With regard to morphological appearance and the tendency of increasing ossification, OPLL of the continuous type was similar to hyperostotic anterior osteophytes, without involvement of intervertebral disc. OPLL of the distinctly continuous type was differentiated from that of the segmental type.