1. 2019;22;E97-E103Prognosis for Recovery of Foot Drop after Transforaminal Endoscopic Decompression of Far Lateral Lumbar 5-Sacral 1 Herniated Disc: Case Series
   Observational Report
   Albert E Telfeian, MD, PhD, Adetokunbo Oyelese, MD, PhD, Jared Fridley, MD, Cody Doberstein, BS, and Ziya L. Gokaslan, MD.

BACKGROUND: Foot drop that results from compression of the exiting L5 nerve as a result of far lateral disc herniation (FLDH) at L5-S1 poses a significant surgical challenge to the minimally-invasive spine surgeon given the narrow corridor for an extraforaminal approach because of the high iliac crest.

OBJECTIVES: Here we describe our experience with transforaminal endoscopic decompression for the treatment of foot drop secondary to FLDH at L5-S1.

STUDY DESIGN: Retrospective case review.

SETTING: This study took place in a single-center, academic hospital.

METHODS: A technique for the transforaminal endoscopic treatment of foot drop secondary to L5-S1 FLDH is presented in a series of 5 consecutive patients treated over a period of 3 years. Preoperative and postoperative clinical data with 1-year follow-up are presented.

RESULTS: A consecutive series of 211 patients who underwent transforaminal endoscopic treatment for lumbar radiculopathy between 2011 and 2014 are presented. Seventy-seven patients had L5-S1 discectomies and 5 of those patients presented with foot drop and FLDH. The mean visual analog scale score for radicular pain improved from an average pain score before surgery of 7.2 to 0.8 one year after surgery, and the mean motor score for anterior tibialis strength improved from an average motor score before surgery of 2.6 to 4.8 one year after surgery.

LIMITATIONS: Small case series evaluated retrospectively with one year follow-up.

CONCLUSIONS: Transforaminal endoscopic surgical access to FLDH pathology may be a unique approach to the treatment of foot drop because it allows for neural decompression of disc and foraminal pathology without requiring significant destabilizing bone removal.

KEY WORDS: Endoscopic spine surgery, minimally-invasive, transforaminal, foot drop, far lateral disc herniation