Comparison of ultrasound-guided versus blind glenohumeral injections: a cadaveric study

Background: Intra-articular glenohumeral (GH) injections are important for diagnostic and therapeutic purposes. It has been suggested that ultrasound guided injections are more accurate than blind or freehand injections. This study assessed the accuracy of ultrasound-guided GH injections compared with freehand injections in fresh cadavers. Methods: The study used 80 shoulder specimens from fresh cadavers. Ultrasound guidance was used to inject radiopaque contrast in 40 shoulders, and freehand technique was used in the remaining 40. All injections were performed by 2 surgeons (A and B) through a posterior approach. After the injections, radiographs were obtained of the specimens to assess the accuracy of the injections. Results: Sixty-six of 80 (82.5%) injections were accurately administered into the GH joint. Ultrasound-guided injections were accurate in 37 of 40 specimens (92.5%) compared with freehand injections, which were accurate in only 29 of 40 specimens (72.5%; P=.02). Both surgeons independently had higher accuracy using ultrasound-guidance compared with the freehand technique (surgeon A: 90% vs 65%, P=0.058; surgeon B: 95% vs 80%, P=0.15). The average time for injections was 52 seconds by the freehand technique and 166 seconds using ultrasound guidance (P<0.001). Conclusions: The data from this cadaveric study suggest that ultrasound-guided injections are more accurate at reaching the GH joint than freehand injections. The ultrasound-guided injections took substantially longer to administer. Once familiar with the technique, surgeons can expect improved accuracy and efficacy of GH joint injections using ultrasound guidance in the clinical setting. Level of evidence: Basic Science Study, Anatomic Study. (C) 2012 Journal of Shoulder and Elbow Surgery Board of Trustees.