Learning Effect for Large Joint Diagnostic Aspirations With Fluoroscopy and Ultrasound

The first objective was to identify whether increased experience, gauged by number of procedures performed posttraining, is correlated with greater likelihood of obtaining joint fluid in diagnostic aspirations. The second objective was to identify whether trainee involvement at the time of procedure affected the success rate of the procedure (which in this case was obtaining fluid on aspiration).

This was a retrospective analysis of fluoroscopic- and ultrasound-guided large joint aspirations. Logarithmic fit was performed to identify the presence of a learning curve to the successful attainment of fluid with experience. Logistic regression analysis was used to identify whether trainee presence for a procedure affected fluid attainment.

Ultrasound did not demonstrate a significant fit to the logarithmic curve ( P = 0.447), whereas fluoroscopy did ( P < 0.001), indicative of a learning curve for fluoroscopy. After adjusting for covariates, joint fluid was successfully attained at a similar rate whether trainees were present or not. Significant independent factors related to successful joint fluid attainment were image guidance technique ( P = 0.001), body mass index ( P = 0.032), and joint aspirated (overall P < 0.001).

There was a statistically significant learning curve for fluoroscopic-guided joint aspirations, but not with ultrasound guidance. Trainee involvement did not affect the success rate of joint aspirations.