Ramon Balius1,2, Antonio Susín3, Carles Morros4, Montse Pujol5,6, Dolores Pérez-Cuenca4, Xavier Sala-Blanch7,8. 1. Consell Català de l'Esport, Generalitat de Catalunya, Barcelona, Spain. ramonbaliusmatas@gmail.com. 2. Sports Medicine Department, Clínica Diagonal, Barcelona, Spain. ramonbaliusmatas@gmail.com. 3. Math Department, UPC-BarcelonaTech, Barcelona, Spain. 4. Anesthesiology, Reanimation and Pain Therapy, Clínica Diagonal, Barcelona, Spain. 5. Consell Català de l'Esport, Generalitat de Catalunya, Barcelona, Spain. 6. Facultad de Fisioteràpia, Universitat Internacional de Catalunya, Sant Cugat del Vallés, Spain. 7. Anatomy and Embryology Unit, Faculty of Medicine, Universitat of Barcelona, Barcelona, Spain. 8. Department of Anesthesiology, Hospital Clínic, Barcelona, Spain.
Abstract
OBJECTIVE: To investigate the behavior of the sciatic nerve during hip rotation at subgluteal space. MATERIALS AND METHODS: Sonographic examination (high-resolution ultrasound machine at 5.0-14 MHZ) of the gemelli-obturator internus complex following two approaches: (1) a study on cadavers and (2) a study on healthy volunteers. The cadavers were examined in pronation, pelvis-fixed position by forcing internal and external rotations of the hip with the knee in 90° flexion. Healthy volunteers were examined during passive internal and external hip rotation (prone position; lumbar and pelvic regions fixed). Subjects with a history of major trauma, surgery or pathologies affecting the examined regions were excluded. RESULTS: The analysis included eight hemipelvis from six fresh cadavers and 31 healthy volunteers. The anatomical study revealed the presence of connective tissue attaching the sciatic nerve to the structures of the gemellus-obturator system at deep subgluteal space. The amplitude of the nerve curvature during rotating position was significantly greater than during resting position. During passive internal rotation, the sciatic nerve of both cadavers and healthy volunteers transformed from a straight structure to a curved structure tethered at two points as the tendon of the obturator internus contracted downwards. Conversely, external hip rotation caused the nerve to relax. CONCLUSION: Anatomically, the sciatic nerve is closely related to the gemelli-obturator internus complex. This relationship results in a reproducible dynamic behavior of the sciatic nerve during passive hip rotation, which may contribute to explain the pathological mechanisms of the obturator internal gemellus syndrome.
OBJECTIVE: To investigate the behavior of the sciatic nerve during hip rotation at subgluteal space. MATERIALS AND METHODS: Sonographic examination (high-resolution ultrasound machine at 5.0-14 MHZ) of the gemelli-obturator internus complex following two approaches: (1) a study on cadavers and (2) a study on healthy volunteers. The cadavers were examined in pronation, pelvis-fixed position by forcing internal and external rotations of the hip with the knee in 90° flexion. Healthy volunteers were examined during passive internal and external hip rotation (prone position; lumbar and pelvic regions fixed). Subjects with a history of major trauma, surgery or pathologies affecting the examined regions were excluded. RESULTS: The analysis included eight hemipelvis from six fresh cadavers and 31 healthy volunteers. The anatomical study revealed the presence of connective tissue attaching the sciatic nerve to the structures of the gemellus-obturator system at deep subgluteal space. The amplitude of the nerve curvature during rotating position was significantly greater than during resting position. During passive internal rotation, the sciatic nerve of both cadavers and healthy volunteers transformed from a straight structure to a curved structure tethered at two points as the tendon of the obturator internus contracted downwards. Conversely, external hip rotation caused the nerve to relax. CONCLUSION: Anatomically, the sciatic nerve is closely related to the gemelli-obturator internus complex. This relationship results in a reproducible dynamic behavior of the sciatic nerve during passive hip rotation, which may contribute to explain the pathological mechanisms of the obturator internal gemellus syndrome.
Authors: Michel W Coppieters; Line S Andersen; Runar Johansen; Per K Giskegjerde; Mona Høivik; Siv Vestre; Robert J Nee Journal: J Orthop Sports Phys Ther Date: 2015-08-24 Impact factor: 4.751