Complete tear of the proximal metacarpal insertion of the radial collateral ligament of the 2nd MCP joint. During dynamic stress, the gap opens clearly with medio-lateral deviation — but notice how I also compress the recesses to move the joint fluid and accentuate the separation. A perfect example of how real-time ultrasound turns subtle findings into unmistakable ones. 💪📸 #mskrad

🔹 Peripheral ulnar TFCC tear — full-thickness and full-width defect of the deep foveal fibers,
extending proximally and partially involving the styloid fibers ⚡️ 💧 The intraarticular fluid (contrast) beautifully outlines the tear,
opening dynamically as the wrist moves 🔄 🩻 This example follows a CT arthrogram,
but we often create similar joint distension with our own US-guided injections 💉 👁️‍🗨️ Learning to recognize the defect under distension
will train your eye to detect it even without it —
that’s where precision begins 🎯

🔎 Dynamic Extensor Tendon Test 🖐️✨ To properly assess the central slip at the PIP joint, you must block the DIP joint. This isolates the central band by preventing the terminal tendon from acting. 👉 Conversely, to evaluate the terminal tendon, stabilize the middle phalanx and move only the distal phalanx. These dynamic maneuvers are designed to evaluate the excursion of the extensor apparatus proximal to the rupture site. This becomes extremely useful when there is diagnostic doubt, helping to distinguish a partial tear (where some degree of excursion remains) from a complete tear (where excursion is absent). These simple tests allow precise differentiation of the extensor mechanism components and reveal subtle injuries that static imaging may miss. #mskrad

Proximal Membranous Band Tear of the Lunotriquetral Ligament Diagnosed with Dynamic Stress Ultrasound – Correlation with Arthro-MRI This case underscores the importance of intra-articular contrast studies, which markedly enhance sensitivity in detecting subtle ligament injuries. Static imaging frequently underestimates these lesions: adjacent ligament remnants or tendon segments may remain closely apposed or seated within their footprint, thereby concealing the actual defect. This is exemplified in the conventional MRI study shown here, where identification of the tear proved nearly impossible. By contrast, dynamic stress ultrasound enabled separation of the gap, clearly exposing and confirming the lesion. Although the injury involves the proximal membranous portion of the lunotriquetral ligament—a region of lesser biomechanical relevance—it demonstrates our ability, and obligation, to actively seek out such lesions when patients are initially referred for ultrasound. In doing so, we can direct them toward the appropriate advanced study, ensuring that the true extent of the injury is accurately defined.