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

Abstract

SummaryBackground: 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.

Gemelli-obturator complex in the deep gluteal space: an anatomic and dynamic study

“…The sciatic nerve has attachment systems that keep anatomical relationships stable in the buttocks [20]. These support mechanisms are formed by collateral branches of the sciatic nerve (the most well-known are superior gluteal nerve, inferior gluteal nerve, posterior skin nerve of the thigh) [1]; but also by the nerves and vessels of the pyramidal, gemellus, obturator internus and quadratus femoris muscles (superior and inferior gluteal arteries with terminal ischial branch). These attachment systems are associated with the paraneural connective tissue, which acts as a Bgliding system^with adjacent tissues or muscles (with its corresponding perimysium).…”

“…In the gluteal space, the sciatic nerve is protected from the sacrum by the pyramidal muscle, and later from the ischium by the gemellus muscles (superior and inferior), the obturator internus, and, finally, the quadratus femoris muscle. This deep pathway to the gluteus maximus is mainly characterized by the nerve's curved layout until reaching the second part of the route, at the level of the thigh [1,2]. Upon reaching the thigh, the sciatic nerve takes on a rectilinear route, deep into the long section of the biceps femoris.…”

“…Due to anatomical variations, repeated microtraumas, or just the passing of years (aging), characteristic clinical cases occur due to nervous dysfunction, like, for example, secondary pseudo-sciatica, or dysfunction caused by entrapment of the sciatic nerve at the level of the piriformis muscle, known as pyramidal syndrome [3][4][5]. Recently, it has been observed that the sciatic dysfunction in the pelvis was not only caused by different types of conflict with the pyramidal muscle, but there were also conflicts at other levels, giving rise to the concept of deep gluteal syndrome [1,2,6]. One of these causes is sometimes attributed to the gemelli-obturator internus complex [7][8][9].…”

The Predisposing Factors of Piriformis Syndrome: Study in a Referral Hospital

“…Long duration of sitting might be as a predisposing factor for piriformis syndrome, supported by the study of Carro et al and Mondal et al (2017). 4,11 However, both studies did not correctly state the duration of sitting a day which could be considered as a predisposing factor. Park et al concluded that inactive populations who sit more frequently for long periods (duration ≥8 hours) have a tendency to experience lower back pain than other populations.…”

Role of sciatic nerve stiffness in surgical decision making and follow up in patients with deep gluteal syndrome

“…Upon surgical exploration of the sciatic nerve, a fibrotic tendinous scar beneath the piriformis was found and released. The resection was done from trochanter's attachment, by separating joint tendon from m. piriformis and m. obturator internus, and by releasing n. peroneus and n. tibialis from fibrous bands and surrounding muscles [15][16][17][18] (Fig 4).…”