[Ossification of the posterior longitudinal ligament of the lumbar spine]

The authors present five cases (4 men, 1 women) of ossification of the posterior lumbar longitudinal ligament. The mean age is 61 years. They emphasize the extreme rarity of this location, its association with ankylosing spinal hyperostosis and diabetes in three patients; they also give a reminder of the characteristics of this radiological symptom. They discuss the etiology on the basis of three hypotheses (disc deterioration, hyperostosis, disease described by Japanese authors).