Full Endoscopic Decompression Surgery for Far-Out Syndrome Via Pseudoarthrosis Formed by L5 Transverse Process and Sacral Ala: A Preliminary Outcome.

Abstract

Far-out syndrome (FOS) refers to the compression of the L5 nerve root in the extraforaminal region by a pseudoarthrosis formed between the L5 transverse process and the sacral ala. If conservative treatment for this condition fails, surgical intervention should be considered. This study aims to introduce a minimally invasive endoscopic technique for treating FOS via the pseudoarthrosis approach. A technical note and preliminary outcome. We retrospectively analyzed the medical history, physical examination, auxiliary examinations, and imaging data as well as the visual analog scale (VAS), Oswestry Disability Index (ODI), and Macnab scores of 5 FOS patients treated with minimally invasive endoscopic surgery at our hospital from April 2024 to July 2024. The implementation process of this surgical technique is illustrated through typical cases. We performed decompression surgery via the L5 transverse process-sacral ala pseudoarthrosis approach using full endoscopy, which successfully relieved the clinical symptoms in the 5 patients. The patients' postoperative VAS scores were significantly lower than the preoperative scores (P = 0.041). Similarly, the postoperative ODI scores were markedly decreased (P = 0.043), and the last follow-up showed a 100% excellent rate (Macnab score). Imaging examination indicated a sufficiently expanded extraforaminal outlet, and the nerve roots were adequately decompressed. The study involved a relatively small number of samples and a short follow-up period. The full endoscopic decompression surgery via the L5 transverse process-sacral ala pseudoarthrosis approach can address the extraforaminal compression in FOS. This procedure is a feasible endoscopic surgical option that serves as a valuable supplement to the minimally invasive treatment for FOS.