Rapid Early Motor Improvement After Full Endoscopic Interlaminar Discectomy for L4–L5 Disc Herniation Presenting With Foot Drop: A Case Report

Lumbar disc herniation with foot drop is a clinically significant presentation because delayed decompression may adversely affect neurological recovery. Full endoscopic interlaminar lumbar discectomy (FELD-IL) is an increasingly adopted minimally invasive technique, but its role in patients presenting with acute motor deficit remains less clearly defined than in routine radiculopathy. We report a case of L4-L5 disc herniation presenting with foot drop that was managed with urgent FELD-IL and resulted in favorable early motor improvement. A 26-year-old man presented with a four-month history of low back pain radiating to the right leg, followed by three days of sudden right foot drop. Neurological examination showed weakness of ankle dorsiflexion and great toe extension (Medical Research Council grade 2/5), decreased pinprick sensation over the dorsum of the right foot and great toe, and a positive straight leg raise test. Lumbar magnetic resonance imaging demonstrated a right paracentral L4-L5 disc herniation with inferior migration compressing the traversing right L5 nerve root. The patient underwent urgent full endoscopic interlaminar lumbar discectomy under general anesthesia. Radicular pain improved immediately after surgery. On postoperative day 1, ankle dorsiflexion improved to MRC 4/5, and at two-week follow-up, the patient had a normal gait and MRC 5/5 strength on bedside examination. Early postoperative magnetic resonance imaging demonstrated satisfactory decompression of the right L5 nerve root. In this selected patient, urgent FELD-IL was technically feasible and was followed by favorable early motor improvement. This case supports the potential applicability of the interlaminar endoscopic approach in carefully selected patients with lumbar disc herniation and foot drop, but it does not establish superiority, safety, or effectiveness relative to other decompressive techniques. Larger comparative studies with longer follow-up are needed before stronger conclusions can be drawn.