3-DIMENSIONAL COMPUTED-TOMOGRAPHY OF OSSIFICATION OF THE SPINAL LIGAMENT

Ossification of the posterior longitudinal ligament in the cervical sp ine was studied 3-dimensionally using computed tomography scans of 32 patients, The images produced were classified into 3 types based on th e posterior configuration of the ossification: (1) plank shaped, (2) s pindle shaped, or (3) rod shaped, Lesions with radiographically contin uous and mixed type ossification on 3-dimensional computed tomography were plank shaped or spindle shaped. Rod shaped type lesions usually w ere radiographically segmented or showed some other type of ossificati on, The 3-dimensional computed tomography images change with the growt h of ossification. Plank shaped type lesions appear to be the final re sult of ossification, Three-dimensional computed tomography scans of o ssification of the longitudinal ligament are useful for decompressive surgery, providing valuable information regarding the site of concentr ation of compression of the spinal cord or nerve roots and the choice of surgical procedures.