EC Orthopaedics

Foraminal stenosis is a type of lumbar spinal canal stenosis. This pathology is a good indication for full-endoscopic decompression surgery using a transforaminal approach, called foraminotomy. However, considering the proximity to the iliac crest, decompression at L5/S1 may be challenging. In this technical note, the technique used to perform foraminotomy at L5/S1 is explained step by step. After local anesthesia with 1% lidocaine, an 8-mm skin incision is made, usually 4 to 5 cm away from the midline. Using a serial dilating maneuver, an 8-mm cannula is docked on the lateral aspect of the superior articular process (SAP). Decompression is started at the SAP and pedicle junction. Drilling then proceeds cranially to the tip of the SAP. About 80% to 90% of the SAP is usually removed, after which the thickened ligamentum flavum (LF) is exposed. The attachment of the LF to the inferior articular process (IAP) of L5 is confirmed. The thickened LF is then detached by drilling the IAP using the high-speed drill. Following removal of the floating LF, the decompressed exiting nerve is visible. Anatomically, the radicular artery runs with the exiting nerve. Pulsation of the nerve is a good indicator of adequate decompression.

Keywords: Full-Endoscopic Decompression; Foraminal Stenosis; L5/S1 Level

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