Ossification of the posterior longitudinal ligament of the cervical spine in Asian Indians--a multiracial comparison.

Ossification of the Posterior longitudinal ligament (OPLL) has been thought to be a predominantly Japanese disease with few reports among the non-orientals and Caucasians. A prospective clinicoradiological study of 47 symptomatic Caucasoid Indians is reported. Twenty-seven patients presented with myelopathy, twelve with myeloradiculopathy and six with radiculopathy. 'Total' configuration of OPLL was the most frequent (70%). The most frequent location was at C3 and C4 levels. The thickness of OPLL ranged from 2.5 mm to 11.5 mm. Canal stenosis was most severe in patients with 'total' type of OPLL. Ossification of other spinal ligaments were seen in 50% of the patients. Twenty-one patients underwent decompressive laminectomy and twenty of them improved. The difference in the cervical canal diameters and the configuration of OPLL between the Japanese and our population (Caucasoid Indians) may be of therapeutic relevance.