Ossification of the spinal ligament. A radiographic reevaluation in Bologna, Italy

A radiographic reevaluation of cervical spine films of 1,258 adult patients and of thoraco-lumbar spine films of 488 of these was performed at the Rizzoli Orthopaedic Institute (Bologne, Italy), in order to detect ossification of the posterior longitudinal ligament (OPLL), the anterior longitudinal ligament (OALL), the yellow ligament (OYL) and the nuchal ligament at the cervical level, and OPLL, OALL and OYL at the thoraco-lumbar level. The incidence of OALL, OYL and ossification of the nuchal ligament corresponded with those previously reported in the literature. Cervical OPLL was found in 1.83%, with a definite prevalence in the 45-64 age group where the figure was 2.83%. This incidence is much higher than that hitherto reported in Caucasians, and is nearly the same as that in Japan. Possible explanations for this discrepancy are proposed.