Estudo das relações anatômicas e suas variações entre o nervo ciático e o músculo piriforme

Abstract

Context: Piriform muscle syndrome can be caused by abnormal passage of the sciatic nerve or one of its parts through the belly of the piriform muscle. Objective: To analyze the anatomical and measurement relationships between the piriform muscle and the sciatic nerve in order to contribute towards better anatomoclinical understanding of the gluteal region. Method: Twenty adult cadavers of both sexes were used. The sciatic nerve and piriform muscle were dissected, measured and photodocumented. Results: The sciatic nerve was seen to be a single trunk passing through the lower margin of the piriform muscle in 85% of the 40 gluteal regions, and 15% showed bilateral variation characterized by the passage of the common fibular nerve through the piriform muscle. The data obtained did not show any statistically significant differences.

Sciatic Nerve Variants and the Piriformis Muscle: A Systematic Review and Meta-Analysis

“…Among them, MRI remains the gold standard. Magnetic resonance neurography can reliably and effectively identify the presence of an SN variant or even SN compression in piriformis syndrome [32,33].…”

Sciatic nerve and its variations: is it possible to associate them with piriformis syndrome?

“…In this review, type 3 was the most common variant. We consider that in order to cause sciatica, the tense piriformis muscle compresses the nerve, or part of it, generating ischemia in its vasa nervorum, causing typical neuropathy 3 . Therefore, when compression occurs in the normal type 1 form, a clinical response compatible with paresthesias and paresis in the areas of competence of the sciatic nerve, classically called sciatica, is to be expected.…”

“…It follows a descending path along the thigh up to the proximal region of the popliteal fossa, where it divides into its terminal branches, the tibial nerve and the common fibular nerve 1 . Although this is the typical anatomical pattern, variations related to the location where the nerve divides, as well as its path in relation to the piriformis muscle, have been observed 3 .…”

“…Schematic representations of the common form (1) and variants(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13) found in the sciatic nerve anatomy in the studies selected for analysis.…”

Evaluation of the sciatic nerve location regarding its relationship to the piriformis muscle

“…Therefore, previous studies paid attention to use several landmarks to locate the position of SN including sacrotuberous ligament and GT [34], IT, ischial spine and GT [12] and acetabulum [10]. In 2015, Robert Haładaj and his colleagues also provided information about the distance from the medial edge of SN and apex of IT and the distance from the lateral edge of SN to GT [13].…”