Traumatic lesions of the discovertebral junction in the lumbar spine.

Lumbar discovertebral abnormalities thought to be due to endogenous or subclinical trauma were evaluated in 22 cases. These consisted of predominantly lytic areas due to intrabody disc herniation in five cases, broad zones of vertebral body sclerosis due to reactive osteitis in 11, and destruction of the vertebral endplates surrounded by diffuse sclerosis in six. Spinal biopsy and negative bacterial cultures were consistent with the diagnosis in eight cases. Follow-up roentgenograms and further clinical evaluation in the remaining 14 showed either no progression or changes consistent with trauma. Only four cases had a history of exogenous trauma. Intrabody disc herniations usually affected the upper vertebral body with characteristic sparing of the adjacent endplate. The sclerotic lesions tended to occur in the anterior portion of the vertebral body, with the inferior aspect of L4 most frequently involved. These may be confused with osteoblastic metastases, particularly if adjacent disc narrowing is minimal. The lack of progressive vertebral fragmentation helps to distinguish this condition from neuroarthropathy. Lesions characterized by destruction of the vertebral endplates and reactive sclerosis simulate infection; absence of a soft tissue mass and clinical signs of sepsis as well as lack of progression are important differential features.