The clinical features of, and microendoscopic decompression for, extraforaminal entrapment of the L5 spinal nerve

Abstract

Objective: To evaluate the clinical results of, and surgical techniques for, microendoscopic (METRx) decompression of extraforaminal entrapment of the L5 spinal nerve at the lumbosacral tunnel.

Methods: Five patients with extraforaminal entrapment of the L5 spinal nerve in the lumbosacral tunnel were treated in our department, including three men and two women. The average age was 65.6 years. All patients suffered severe leg pain and neurological deficits compatible with L5 radiculopathy. Minimally invasive decompression of the L5 spinal nerve was performed under METRx intertransverse decompression.

Results: With an average follow-up of 17.8 months, clinical results were assessed based on Nakai criteria and Visual Analogue scale (VAS). All patients experienced immediate pain relief postoperatively. Clinical outcomes were excellent in three patients and good in two. The average intraoperative blood loss was 59 ml, with an average operative time of 103 min. Average post-operative stay in bed was 7 days, and average cost was $1860.

Conclusion: Extraforaminal entrapment of the L5 spinal nerve in the lumbosacral tunnel can cause L5 radiculopathy. METRx partial resection of the L5 transverse processes, sacral ala and osteophytes of L5-S1 vertebral bodies to relieve extraforaminal entrapment of the L5 spinal nerve is a very effective and minimally invasive surgical option.

Figure 1

A typical patient, male, 64 years old, complaining of low back pain and left leg pain, presenting weakness of extensor hallucis longus, and straight leg raising sign positive at 40°. (A, B) Osteophyte formation at posterior and inferior edge of L5 vertebra; (C) Removal of inferior part of L5 transverse process; (D) Partial removal of sacral ala using high speed burr to enlarge the L5‐S1 intertransverse space; (E) Retraction of intertransverse membrane by nerve retractor to expose L5 nerve root; (F) Removal of adjacent osteophyte by high speed burr; (G) Dissection and release of L5 nerve root by nerve dissector.