Transdural Nerve Rootlet Entrapment in the Intervertebral Disc Space through Minimal Dural Tear : Report of 4 Cases
A 49-year-old female had back pain and left leg pain for 6 months. Initial MRI showed extraforaminal disc herniation at L4-5 on the left side (). She underwent PELD at this location. Her symptoms improved but recurred after 2 months. Repeat MRI showed recurrence of extraforaminal and paramedian disc herniation at the L4-5 level on the left side (). She underwent HLD on the left side with interspinous soft stabilization at the L4-5 level. During the operation, a severe ventral dural adhesion was observed that was attributed to prior endoscopic surgery. The patient's symptoms improved after surgery. However, she again complained of left leg pain after 20 days. Repeat MRI showed rootlet entrapment through a dural defect at the L4-5 level on the left side (). During subsequent operation, L5 nerve root entrapment through the dural defect was confirmed. The small ventral dural defect may not have been identified during the previous operation. We repositioned the entrapped rootlet and performed duroplasty. Her symptoms improved and finally disappeared after 6 months.