1050 - Accuracy of Radiohumeral Joint Injections: Ultrasound vs. Landmark Guidance in Experienced and Novice Practitioners

Objectives: To compare the accuracy of ultrasound-guided versus landmark-guided radiohumeral joint injections and assess the effect of practitioner experience on injection accuracy.
 

Design: Forty injections were performed on cadaveric specimens targeting the radiohumeral joint. One experienced PM&R practitioner performed 18 total injections: 9 using ultrasound guidance and 9 using landmark-based techniques. Two medical students performed 10 and 12 injections respectively, with each student performing half of their injections using ultrasound guidance and half using landmark guidance. Injection accuracy was confirmed by cadaveric dissection and defined as successful if more than 50% of the injected dye was located within the radiohumeral joint.
 

Results: The experienced practitioner achieved 89% accuracy (8/9) with ultrasound guidance and 78% accuracy (7/9) using landmark guidance.
Medical Student 1 achieved 80% accuracy (4/5) with ultrasound and 40% accuracy (2/5) using landmarks.
Medical Student 2 achieved 67% accuracy (4/6) with ultrasound and 50% accuracy (3/6) using landmarks.
Ultrasound guidance consistently demonstrated higher accuracy across all practitioner levels. The experienced practitioner outperformed both medical students regardless of technique, but the performance gap between novices and the experienced practitioner narrowed when using ultrasound.
 

Conclusions: Ultrasound guidance improves the accuracy of radiohumeral joint injections, particularly among novice practitioners. While experienced clinicians demonstrate high accuracy with both methods, ultrasound significantly benefits less experienced injectors by reducing variability and improving precision. These findings support incorporating ultrasound training into musculoskeletal procedural education to enhance safety and efficacy in joint injection techniques.