Update on Adult Acquired Flat Foot Deformity Using MR Imaging.

Adult acquired flatfoot deformity (AAFD) is a progressive condition characterized by collapse of the medial longitudinal arch, pain, and functional impairment. It predominantly affects middle-aged women and is associated with obesity, diabetes, hypertension, and anatomic variants. MR imaging is the gold standard for evaluating osseous, tendinous, and ligamentous structures, enabling accurate diagnosis and staging. This review summarizes the role of MR imaging in AAFD, detailing normal anatomy, pathophysiological mechanisms, classification systems, and advanced imaging protocols. Key MR imaging findings include posterior tibial tendon dysfunction, spring and deltoid ligament involvement, and secondary osseous changes.