Comparing fluoroscopic versus ultrasound guidance in glenohumeral joint aspiration

Background Joint aspiration is a common technique used to aid in the diagnosis of glenohumeral pathology. Fluoroscopy and ultrasound are both used as image-guidance methods to increase the accuracy of the procedure. There are no prior studies comparing the ability of these two methods to obtain joint fluid. Objective To evaluate whether fluoroscopy or ultrasound-image guidance more often obtains fluid from the glenohumeral joint and which technique obtains a greater amount fluid. Design Retrospective cohort study. Setting Single academic orthopedic clinic. Patients A total of 206 patients undergoing glenohumeral aspiration, generally to rule out infection. Interventions Fluoroscopic- or ultrasound-guided joint aspirations, performed by numerous physicians. Main Outcome Measures Primary was the successful aspiration of at least 0.1 mL of joint fluid; secondary was the total amount of joint fluid obtained. Results There was no significant difference in rate of successful aspirations between ultrasound (69.4% successful; 95% confidence interval [CI] = 54.4%, 84.5%) and fluoroscopy (70.6% successful; 95% CI = 63.7%, 77.4%). The amounts of fluid obtained by fluoroscopy and ultrasound did not differ significantly (p = .349; mean +/- standard deviation [SD] = 7.1 +/- 12.6 vs. 10.0 +/- 16.8 mL; median [interquartile range [IQR] = 3 [7] vs. 5 [8.75] mL). Sub-analysis showed that significantly more fluid was obtained with fluoroscopy in patients with a >35 body mass index (BMI) (adjusted mean = 7.9 mL; 95% CI = 4.3, 11.5) when compared with ultrasound (2.3 mL; 95% CI = 0.6, 4.0). Conclusions Fluoroscopic- and ultrasound-guided aspirations of the glenohumeral joint demonstrate similar success in obtaining fluid. For nonobese patients, ultrasound guidance is typically less expensive, office-based, less uncomfortable, and allows for dynamic visualization. For obese patients, fluoroscopy appears to have an advantage with respect to the amount of fluid obtained. Prospective studies are warranted to make more robust conclusions.