1042 - Accuracy of Metatarsophalangeal Joint Injections: Ultrasound vs. Landmark Guidance in Novice and Experienced Practitioners

Objectives: To compare the accuracy of ultrasound-guided versus landmark-guided metatarsophalangeal (MTP) joint injections and assess the effect of provider experience on injection success.
 

Design: Cadaveric study evaluating 36 MTP joint injections. One experienced PM&R practitioner performed 12 injections (6 ultrasound-guided, 6 landmark-guided) into the first MTP joint. Two medical students each performed 12 injections, with half performed using ultrasound guidance and half using landmark-based techniques. Injection accuracy was assessed via cadaveric dissection and defined as accurate when more than 50% of injected dye was located within the target MTP joint.
 

Results: The experienced practitioner achieved an accuracy of 83% for both ultrasound-guided (5/6) and landmark-guided (5/6) MTP joint injections. Medical Student 1 demonstrated 50% accuracy with ultrasound guidance (3/6) and 33% accuracy with landmark guidance (2/6). Medical Student 2 achieved 67% accuracy with ultrasound guidance (4/6) and 83% accuracy with landmark guidance (5/6). Overall, the experienced practitioner maintained high accuracy regardless of technique, while novice performance was more variable. Across all injections performed, accuracy rates for ultrasound and landmark guidance were comparable.
 

Conclusions: For MTP joint injections, provider experience appears to have a greater influence on accuracy than the choice of ultrasound versus landmark guidance. The experienced practitioner achieved consistent results with both techniques, while novice performance was more variable. These findings suggest that for small peripheral joints such as the MTP, ultrasound may not confer a universal accuracy advantage, though it may benefit some novice injectors. Further studies with larger sample sizes are warranted to clarify these trends and assess statistical significance.