Histological Feature of Ossification of the posterior longitudinal ligament of the spine

Abstract

Histological Feature of Ossification of the posterior longitudinal ligament of spine (OPLL) was studied using undecalcified grinded sections. All specimen were obtained from patients with OPLL, who had already done double bone labelling. The specimens were observed by light, polarized, and fluoro-microscopies.
Tetracycline bone labelling was found at the level of vertebral edge in OPLL. but little bone labelling was found in the middle part of OPLL.
Mineral apposition rate (MAR), which was calculated from double labelled width, was compared among ilium, vetebra, rib, and OPLL. The patients with OPLL were deviled into two groups; the OPLL group, which showed symptom due to OPLL, and the CSM+OPLL group, which showed symtom due to cervical spondylosis, not OPLL. In both groups, MAR in vertebra was higher than that in ilium. But MAR in OPLL was changeable. In OPLL group, MAR in OPLL was higher than that of ilium, vertebra, and rib. In CSM+OPLL group, MAR in OPLL was same to that of vertebra.