Ultrasound-Guided Gluteal Fascial Plane Block for the Treatment of Chronic Refractory Greater Trochanteric Pain Syndrome - Technique Description and Anatomical Correlation Study. - Ferreira-Dos-Santos G; Hurdle MFB; Tran J; Eldrige JS; Clendenen SR; Agur AMR (Pain medicine (Malden, Mass.), 2022)