SURGICAL PROCEDURE:
The aim of surgery was to prevent the tethering effect on the cord by the fibro-neural stalk. A midline vertical skin incision encompassed the flat lesion. Then, the incision was deepened, and the tract was dissected off the fascial defect. There was the absence of L5-S1 posterior elements. L4 laminectomy was done. The dural tube, tract, and skin lesion were delineated separately.
The simulation threshold for the filum / non-functioning tract was at 100 times the root/rootlets. The dura was opened, and tract stimulation (10mA) was carried out to demonstrate the absence of neural elements. Then, the tract was disconnected with the dura fully opened. The filum was identified and, upon stimulation (10mA), showed no response (Figure 4 A-E ). The quadriceps, anterior tibialis, Abductor Hallucis and External Anal Sphincter, were assessed before the closure by triggered EMGs at 1 mA current and the recordings are attached in the figure. The operation was concluded by performing dural reconstruction using 6-0 prolene. The lumbodorsal fascia was reconstructed. Lastly, the subcutaneous tissue and skin were closed in layers, and a sterile dressing was applied. The post-operative period was uneventful.