Deep gluteal syndrome: anatomy, imaging, and management of sciatic nerve entrapments in the subgluteal space

Abstract

Deep gluteal syndrome (DGS) is an underdiagnosed entity characterized by pain and/or dysesthesias in the buttock area, hip or posterior thigh and/or radicular pain due to a non-discogenic sciatic nerve entrapment in the subgluteal space. Multiple pathologies have been incorporated in this all-included "piriformis syndrome," a term that has nothing to do with the presence of fibrous bands, obturator internus/gemellus syndrome, quadratus femoris/ischiofemoral pathology, hamstring conditions, gluteal disorders and orthopedic causes. The concept of fibrous bands playing a role in causing symptoms related to sciatic nerve mobility and entrapment represents a radical change in the current diagnosis of and therapeutic approach to DGS. The development of periarticular hip endoscopy has led to an understanding of the pathophysiological mechanisms underlying piriformis syndrome, which has supported its further classification. A broad spectrum of known pathologies may be located nonspecifically in the subgluteal space and can therefore also trigger DGS. These can be classified as traumatic, iatrogenic, inflammatory/infectious, vascular, gynecologic and tumors/pseudo-tumors. Because of the ever-increasing use of advanced magnetic resonance neurography (MRN) techniques and the excellent outcomes of the new endoscopic treatment, radiologists must be aware of the anatomy and pathologic conditions of this space. MR imaging is the diagnostic procedure of choice for assessing DGS and may substantially influence the management of these patients. The infiltration test not only has a high diagnostic but also a therapeutic value. This article describes the subgluteal space anatomy, reviews known and new etiologies of DGS, and assesses the role of the radiologist in the diagnosis, treatment and postoperative evaluation of sciatic nerve entrapments, with emphasis on MR imaging and endoscopic correlation.

Quantitative magnetic resonance (MR) neurography for evaluation of peripheral nerves and plexus injuries

“…Clinical manifestations of sciatic nerve are common, and are challenging to study with MRI due to its length. Sciatic nerve entrapment usually occurs at a pelvic level, the so-called piriformis syndrome, due to a mass compression, trauma or a compression neuropathy (68,69). According to some authors, the existence of a piriformis hypertrophy, as may occur in runners, or accessory muscle can condition compression on the sciatic nerve and justify the symptoms (70,71 …”

Current concepts in the diagnosis and management of extra-articular hip impingement syndromes

“…Deep gluteal syndrome does not have any particular osseous pathomorphology on the plain radiographs. MRI is the imaging modality of choice for assessing this syndrome and may substantially influence the management of these patients [56]. The diagnostic injection test is also a useful tool, enabling diagnosis and excluding articular pathology or other extra-articular disorders.…”

Treatment of proximal hamstring tendinopathyrelated sciatic nerve entrapment: presentation of an ultrasound-guided �Intratissue Percutaneous Electrolysis� application

“…Proximal Hamstring Tendinopathy-related Sciatic Nerve Entrapment (PHTrSNE) therefore represents a possible complication of PHT. Rapid movements of hip flexion and extension or maximum hip flexion can worsen the symptoms, being the SN bound to the hamstring tendon complex (anchoring fibrosis) 1,3,6,8 . However, distinguishing symptoms of tendinopathy from those of neuropathy is fairly complicated.…”