The sciatic gliding space

This study investigates the connective tissue structures that enable the sciatic nerve to glide through the deep gluteal and upper limb area. Characterizing the gliding space may improve the understanding of non-discogenic sciatica and support clinical approaches to its treatment.

Thirty limbs of alcohol- and Thiel-fixed specimens (21 female, 9 male; mean age 85.2 years) were examined using macroscopic dissection. Additional visualization was achieved through methacrylate corrosion casts. Ultrasound examinations were performed on specimens and two healthy volunteers to assess the sciatic nerve and its surrounding connective tissue during movements.

Dissections consistently revealed a C-shaped anatomical space surrounding the sciatic nerve, bordered by distinct connective tissue folds ("arches") linking the nerve to pelvitrochanteric muscles and the adductor magnus muscle. This Sciatic Gliding Space (SGS) extended from the infrapiriform foramen into the proximal thigh, where it was divided by a sagittal septum. The SGS was identifiable through blunt dissection, injection, and sonography. Sonography demonstrated its dynamic adaptation during hip rotation. In 29 of 30 cases, the SGS appeared unobstructed, while one case showed fibrous structures comparable to fibrovascular tissue described in deep gluteal syndrome.

The SGS represents a structured anatomical space bordered by lamina of connective tissue (telae). It may facilitate vascular supply and tension-free gliding of the sciatic nerve. Recognition of this space may provide an anatomical basis for sciatic pain syndromes and guide endoscopic and sonographic diagnostic or therapeutic strategies.