Sciatic Nerve Entrapment (Deep Gluteal Syndrome) as a Cause of Failed Back Surgery Syndrome: A Case Report

Abstract

Sciatic nerve entrapment, which is a cause of non-discogenic extraspinal sciatica is characterized by buttock pain and sitting intolerance. If significant asymptomatic lumbar stenosis in the lower lumbar spine is found in patients with buttock pain and sciatica, caused by sciatic nerve entrapment, it is possible that needless spinal surgery may have been recommended. A 72-year-old male presented with a 2-year history of severe buttock and sole pain in his right lower extremity. His pain did not improve after decompression and fusion surgery for severe lumbar stenosis. A pelvic magnetic resonance imaging (MRI) used to evaluate the failed back surgery syndrome revealed a type II variation between the sciatic nerve and piriformis muscle. Transgluteal decompression of the sciatic nerve completely eliminated chronic disability associated with right buttock and sole pain. The patient's pain was improved by sciatic nerve decompression through a transgluteal approach. Although vascular claudication, hip joint pathology, and peripheral neuropathy have been suggested in the differential diagnosis of lumbar stenosis, sciatic nerve entrapment involving the gluteal region should be suspected in patients presenting with buttock pain associated with sciatica, combined with severe lumbar stenosis based on MRI.

Importance of Sacrotuberous Ligament in Transgluteal Approach for Sciatic Nerve Entrapment in the Greater Sciatic Notch (Piriformis Syndrome)

“…Although first described in 1928 and coined in 1947 [ 27 , 37 ], the precise pathophysiology of piriformis syndrome is still not defined. It is still regarded as a controversial but potentially common [ 4 , 13 ], underdiagnosed cause of buttock pain and non-discogenic cause of sciatica [ 7 , 10 , 14 , 22 , 24 , 28 ], and even a cause of failed back surgery syndrome [ 6 , 15 , 30 ].…”

The Transgluteal Approach for Decompression of Sciatic Nerve Entrapment (Piriformis Syndrome) with Intraoperative Neurophysiology: A Technical Note

“…Entrapment of the sciatic nerve at any point along its course can result in a clinical syndrome of buttocks and leg pain known as sciatica, with a reported incidence as high as 43% 13,15) . A less common and under-diagnosed cause of sciatica is sciatic nerve entrapment in the gluteal region (formerly called pyriformis syndrome) 9) . Piriformis syndrome was classically thought to result from hypertrophy and in-Although the transgluteal approach splitting the gluteus maximus muscle has been reported as a posterior approach for sciatic nerve entrapment (piriformis syndrome), detailed descriptions of the surgical steps and intraoperative findings have not been published.…”

“…Sciatic entrapment can occur in both type 1 and type 2 variations of the sciatic nerve in the subgluteal space 21) . Patients with sciatic nerve entrapment who do not respond to conservative treatment generally require surgical decompression 9,21) .…”

“…The transgluteal approach allows access to lesions involving the hip, the sciatic nerve, and the pudendal nerve via dissection of the gluteus maximus muscle in the buttock. Sciatic nerve entrapment, previously known as piriformis syndrome 9) , has recently been classified as a deep gluteal syndrome (DGS) 7) . The incidence of hip and leg pain due to sciatic nerve entrapment remains unknown.…”

“…The incidence of hip and leg pain due to sciatic nerve entrapment remains unknown. However, its importance has recently been emphasized as one of the causes of failed back surgery syndrome and DGS 7,9) .…”