Deep gluteal space problems: piriformis syndrome, ischiofemoral impingement and sciatic nerve release

Abstract

Background: 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. Methods: This article describes the subgluteal space anatomy, reviews known and new etiologies of DGS, and assesses the role of the radiologist and orthopaedic surgeons in the diagnosis, treatment and postoperative evaluation of sciatic nerve entrapments. Conclusion: DGS is an under-recognized and multifactorial pathology. The development of periarticular hip endoscopy has led to an understanding of the pathophysiological mechanisms underlying piriformis syndrome, which has supported its further classification. The whole sciatic nerve trajectory in the deep gluteal space can be addressed by an endoscopic surgical technique. Endoscopic decompression of the sciatic nerve appears useful in improving function and diminishing hip pain in sciatic nerve entrapments, but requires significant experience and familiarity with the gross and endoscopic anatomy. Level of evidence: IV.KEY WORDS: hip arthroscopy, hip endoscopy, sciatic nerve entrapment, deep gluteal syndrome, piriformis syndrome, ischiofemoral impingement.

Piriformis Syndrome: A Narrative Review of the Anatomy, Diagnosis, and Treatment

“…Furthermore, a palpable, tender, sausage‐like mass over the piriformis muscle was one of Robinson's original six criteria to diagnose piriformis syndrome . Furthermore, fibrous bands in the area of the piriformis and other posterior hip girdle muscles have been described in piriformis syndrome . However, given the relatively small size and deep depth of the piriformis muscle within the buttock, the accuracy of piriformis muscle palpation has been called into question .…”

Conventional and Arthrographic Magnetic Resonance Techniques for Hip Evaluation: What the Radiologist Should Know

“…Radiologically, the sciatic nerve can be easily identified as a round structure with a 0.9-to 1.2-cm mean diameter which is surrounded by fat in the middle third between the ischium and greater trochanter. 28,29 Clinically, patients complain about buttock pain with frequent associated dysesthesias. Any lesion (gynecologic pathologies, tumors, infections, or traumatic causes) that occupies the subgluteal space can entrap the sciatic nerve and lead to pain.…”

“…Extraforaminal sciatic pain most frequently originates from the gluteal region. 28,29 For an accurate assessment of the deep gluteal space, a high field strength magnet with a multichannel body coil and a combined morphological and neurographic protocol is needed. Morphological images include T1-weighted and fat-suppressed proton-density (PD)-weighted sequences in three planes at a large FOV.…”

“…However, often not all of these signs are present, making the diagnosis challenging. [28][29][30] In our institution we also routinely add high-resolution and high-contrast isotropic coronal three-dimensional (3D) STIR, coronal 3D balanced gradient-echo images, and axial diffusion-weighted images. Isotropic sequences allow multiplanar reconstruction and curved reconstruction aligned with the long axis of the sciatic nerve.…”

“…31 Lumbar spine origin of the sciatic pain should be ruled out by at least one examination. 28,29 Adductor Tendons, Pubic Symphysis…”