Thoracic radiculopathy caused by ossification of the ligamentum flavum
A 67-year-old male visited our clinic with severe back pain radiating to the right abdomen without preceding trauma. The symptom deteriorated while sitting or standing. It was completely relieved by supine position. He has had diabetes mellitus for 5 years treated by medication.\nNeurological examination revealed mild sensory deficit at the right side of the abdomen at the T9–10 level. Manual muscle testing showed no muscle weakness of lower extremities. The tendon reflexes were normal.\nPlain radiographs of the thoracic spine showed mild degenerative changes in the T3 to T11 vertebral bodies and discs (). T2-weighted magnetic resonance imaging (MRI) demonstrated thickening of the ligamentum flavum at the right T9–10 level (). Computed tomography (CT) after conventional myelography demonstrated OLF at the right T9–10 and bilateral T10–11 levels. Though compression of the spinal cord was not clear, compression of the right T9 nerve root at the T9–10 level was suspected (). We performed a selective nerve root block of the right T9 nerve root for diagnostic treatment. The patient's pain decreased just after the procedure; however, the effect was temporary. From these findings, we diagnosed right T9 radiculopathy caused by OLF at the right T9–10 level.\nPain killers were prescribed at first, but the symptoms did not improve. Then an operation was scheduled. Because there remained a possibility that OLF at the right T10–11 level contributed to the symptoms and the patient occasionally complained about left back pain, fenestrations of the right T9–10 and bilateral T10–11 levels were performed under general anesthesia. Epidural fat tissue disappeared at the right T9–10 level, which indicated that OLF compressed the dura matter. OLF at the T10–11 level was smaller than that of the T9–10 level, and there was no apparent compression sign of the T10 nerve roots.\nThe pain disappeared, and sensory deficit improved just after the operation. CT after the operation demonstrated that decompression was enough at the right T9–10 () and bilateral T10–11 () levels.\nThe patient was informed that his clinical data would be summarized in a manuscript and be submitted for publication. He gave his consent.