Acutely progressing paraplegia caused by traumatic disc herniation through posterior Schmorls node opening into the spinal canal in lumbar Scheuermanns disease

Study Design: A case report. Objective: To report an unusual neurologic complication caused by traumatic disc herniation through atypical posterior Schmorls node (SN) opening into the spinal canal in lumbar Scheuermanns disease. Summary of Background Data: Neurologic complications in Scheuermanns disease are rare and disc hernia has been reported as one of the causes of neural compression. However, there has been no report on acutely progressing paraplegia caused by traumatic disc herniation through an atypical posterior SN opening into the spinal canal in lumbar Scheuermanns disease. Methods: A clinical and radiologic review of such a case of traumatic disc herniation through an atypical posterior SN that resulted in acutely progressing paraplegia in Scheuermanns disease was performed. Results: The patient presented with severe back pain after a fall, without any neurologic abnormalities. Computed tomographic scan revealed lumbar Scheuermanns disease, acute compression fracture of T12, and a large posterior SN with "trough-like" indentation of the lower endplate of T12 opening into the spinal canal. Abruptly progressing paraplegia occurred in less than 24 hours after the first visit and the magnetic resonance imaging revealed severe spinal cord compression by large disc extrusion with superior migration at T12-L1 through the atypical posterior SN at the lower endplate of T12. The patient underwent posterior decompression and discectomy at T12-L1 through transfacet pedicle-sparing approach. Postoperatively, the patient showed immediate improvement in the sensory deficit on L1 dermatome and the perianal area and motor function of the hip flexors to grade 2 without further neurologic improvement, at 2-year follow-up. Conclusion: The case report highlights the clinical significance of the atypical posterior SN that could be a channel for large disc extrusion after a traumatic event in Scheuermanns disease and the clinical importance of surgeons close attention to the possibility of abruptly progressing neurologic compromise in this situation.