USMSIT/NMUSIT Fundamental Guide on Diagnostic and Interventional Elbow Ultrasonography.

Elbow pain arises from diverse tendinous, ligamentous, neural, and bursal disorders involving the lateral, medial, anterior, and posterior compartments. Because clinical symptoms frequently overlap - such as epicondylitis, distal biceps tendon injury, cubital tunnel syndrome, and olecranon bursitis - precise imaging is essential for accurate diagnosis and targeted management. Ultrasonography has become a first-line modality for elbow evaluation due to its high-resolution visualization, dynamic capability, and real-time interventional guidance. This article presents the Ultrasound Musculoskeletal Workshop in Taiwan (USMSIT)/Neuromuscular Ultrasound Workshop in Taiwan (NMUSIT) Fundamental Guide on Diagnostic and Interventional Elbow Ultrasonography, a standardized compartment-based protocol developed within the educational framework of the USMSIT and the NMUSIT. The guide systematically describes probe positioning, key anatomical landmarks, and normal sonoanatomy for assessment of the common extensor tendon, anterior joint recess, distal biceps tendon, common flexor tendon, cubital tunnel, and posterior elbow structures. Representative sonographic features of common pathologies - including tendinopathy, partial tear, joint effusion, ulnar neuropathy, and olecranon bursitis - are outlined, with emphasis on Doppler evaluation and dynamic maneuvers. In addition, step-by-step ultrasound-guided interventional techniques are summarized, including tendon injection, joint aspiration, ulnar nerve hydrodissection, and bursal aspiration. By integrating diagnostic and therapeutic principles within a structured framework, this guide provides a practical and reproducible reference for clinicians performing elbow ultrasonography.