Traumatic Intradural Lumbar Disc Herniation without Bone Injury
A 52-year-old man presented at the hospital with numbness in his left calf and ankle after falling accident two days ago. The patient was initially admitted at another medical center after the accident but transferred to our hospital at his request. A motor power grade was intact with slightly decreased sensation along the left L5 dermatome. The patient did not have back pain. Bladder and bowel functions were intact, and no other significant abnormalities were found upon neurological examination.\nIn his medical history, he had visited our hospital six weeks ago with complaints of radiating pain in his right leg along the L5 dermatome after falling down from 2m height. At that time, his lumbar spine magnetic resonance image (MRI) scan exhibited diffuse bulging intervertebral disc in L4-5 (). The patient had received a conservative treatment with a non-steroidal anti-inflammatory drug and discharged with the improvement of symptoms.\nAt this time, the patient's plain radiography did not present bony abnormalities such as fractures or dislocations. In his lumbar computed tomography (CT) scan, a small calcified lesion was found at the L1-2 level, posterior to the disc (). On his lumbar T2-weighted MRI, a high signal intensity with an amorphous shape lesion was located intradurally and it compressed the spinal cord anteriorly at the L1 level (). In his gadolinium-enhanced MRI, the lesion exhibited mild rim enhancement () and it presented heterogeneous low signal intensity in the gradient echo (GRE) image (). We considered the lesion to be a spinal SDH, and decided to perform a conservative treatment. At the follow up MRI scan after two weeks of treatment, the lesion still remained unchanged without any improvement of numbness, so we decided to operate.\nA subtotal laminectomy was performed at L1, which revealed an out-punching whitish soft particle on the dorsal dura. The particle was thought to be a ruptured disc material and removed gently, then sent for pathology. The pathologic results determined the particle to be degenerating fibrocartilagenous tissue corresponding to an intervertebral disc. After removing the extradural lesion, a midline durotomy was done from the dura defect uncovering large, cartilaginous disc particles in the middle of the intradural space (). After removing the disc particles, a hard bony lesion remained adhesively to the ventral dura and a small ventral dura defect was identified around the bony lesion (). The hard bony lesion was thought to be a calcified lesion at the posterior L1/2 intervertebral disc in his lumbar spinal CT scan. We tried to repair the dura defect to protect a leakage of cerebrospinal fluid (CSF), but the ventral dura tear could not be repaired due to its severe adhesion. A watertight closure on dorsal dura was performed. After the operation, the patient's numbness in his left leg has gradually improved. Two weeks after surgery, the patient was discharged from the hospital with free of symptoms.