[A case of myelopathy caused by calcified nodules of cervical ligamentum flavum].

A case is reported of a 71-year-old female with cervical myelopathy caused by calcified nodules in the cervical ligamentum flavum and improved by en bloc laminectomy. The calcified nodules were formed by the deposition of two crystals, hydroxyapatite (HAP) and calcium pyrophosphate dihydrate (CPPD). Light microscopy, scanning electron microscopy, energy dispersive X-ray microanalysis and X-ray diffraction study disclosed that the larger nodule located on the right was composed mainly of HAP in the central part and CPPD in the circumference. On the other hand, the smaller nodule located on the left was composed mainly of CPPD crystal. These findings support the hypothesis that calcification of the ligamentum flavum and CPPD crystal deposition disease in the cervical region are the same entity and the both are merely different aspects of the same entity at different chronological stages.