Diagnostic Musculoskeletal Ultrasound in the Evaluation of the Triangular Fibrocartilage Complex

The wrist joint is a common site of pain and injury due to either overuse or acute trauma. Many instances of wrist pain occur on the ulnar side of the wrist. This side of the wrist is commonly referred to as the "black box" of the wrist due to its small size and complex anatomy. Housed within the ulnar side of the wrist is the triangular fibrocartilage complex (TFCC). The TFCC is a complex of soft tissues that serves as a shock absorber and stabilizer of the distal radioulnar joint (DRUJ). This entire complex around the DRUJ and TFCC is composed of a central articular disc, a dorsal/volar radioulnar ligament, ulnar collateral ligament, and the extensor carpi ulnaris sheath. Diagnostic musculoskeletal ultrasound (MSKUS) offers a portable, real-time, and cost-effective alternative that is gaining traction in rehabilitation and sports medicine settings. MSKUS has emerged as a valuable, non-invasive imaging modality for evaluating wrist ligaments, discs, and bone. MSKUS is excellent at detecting changes in ligament composition and continuity. This manuscript will review the utility of MSKUS in evaluating TFCC and DRUJ injuries, including anatomy, common injury patterns, sonographic techniques, and clinical implications for rehabilitation professionals. Due to the small size and variety of structures in a confined space, diagnosing acute injury by physical examination is often difficult. By integrating MSKUS into clinical practice, providers can improve diagnostic accuracy, enhance diagnostic confidence, monitor healing progression, and guide rehabilitation strategies to achieve optimal patient outcomes for patients with wrist injuries.