OSSIFICATION OF THE POSTERIOR LONGITUDINAL LIGAMENT MIMICKING CORD COMPRESSION FROM A DORSAL DISC PROTRUSION - A CAUTIONARY TALE

A patient with focal anterior compression of the dorsal cord at the le vel of the D6/7 disc was mistakenly diagnosed as a dorsal disc protrus ion on the basis of CT myelography. The CT scanning had been confined to axial views at the level of the cord compression. A transthoracic e xploration failed to reveal a disc protrusion and the correct diagnosi s, ossification of the posterior longitudinal ligament, was only revea led by a subsequent sagittal CT scan. This case emphasizes the dangers of relying on limited axial imaging in diagnosing a spinal lesion.