The pulleys: from the anatomical and histological basis to sonoanatomical characterization

[eng] INTRODUCTION: Digital annular pulleys (DAP) are important anatomical structures for finger function. The anatomy, histology and imaging assessment of DAP, particularly at the level of their entheses, has not been defined and the reliability of ultrasound (US) in measuring DAP and studying DAP entheses has not yet being evaluated. The advent of high-frequency US transducers opened new perspectives in evaluating submillimeter-scale structures, such as pulleys, paving the way for their global assessment with impressive resolution. HYPOTHESIS: Digital annular pulleys insertions are anatomical entheses and present organized fibrous and fibrocartilaginous tissue at the interface between collagen fiber, belonging to the proper pulleys, and the cortical bone in which they insert. US, can explore DAP entheses in all fingers, including the thumb. OBJECTIVES: The present research aimed to characterize DAP of all fingers of the hand, including the thumb, from an anatomical, histological and US perspective, focusing on the detection and complete description of pulley entheses.