The Clinical Significance of Low Thoracic Vertebral and Thoraco lumbar Posterior Marginal Intraosseous Cartilaginous Nodes

Objective To study the clinical features, etiology and pathology of posterior marginal intraosseous cartilaginous node of the thoracic vertebrae. Methods 6 cases of thoracic and thoracolumbar spinal compression were proved with plain X-ray film and CT scanning to have 9 posterior marginal intraosseous cartilaginous nodes:4 cases have one each, and the other two have 2 and 3 respectively; one at the inferior margin of T11, five at the inferior margin of T12 , one at the superior margin of T12 , and one at the inferior margin of L 1 and L 2 respectively. Lateral X-ray film showed that 5 cases presented defects and free bone fragments. At postero inferior or postero superior angles of the vertebrae there were linear cracks and osteosclerosis at the corresponding regions; two had horizontal defect and osteosclerosis in the posterior 1/3-1/2 region of the end plates of the vertebrae; 2 had posterior marginal osteophytes. CT scanning revealed vertebral canal defects and osteosclerosis at posterior aspect of the vertebrae, 5 defects were elliptical and the other 4 irregular with the same density as the intervertebral discs, ranging from sizes of 4 mm×6 mm-10 mm×15 mm;the defect marginal osteosclerosis expanded towards the interior of the vertebrae, together with the posterior marginal, linear or arched plate ossifying shadow projecting into the vertebral canal. 2 cases had simultaneously ossification of ligamentum flavum. Results All the cases were treated with the posterior decompression and two cases had additional anterio lateral decompression with excision of the transverse rib process. At the follow up study, 4 had excellent, 1 good and the other one poor result. Conclusion The cartilaginous node of inferior thoracic vertebrae and that at the posterior thoraco lumbar margin has the same X-ray and CT scanning manifestation as the lumbar posterior marginal intraosseous cartilaginous node.