Miley LK, Boyum JH, McDonald JS, Horst KK, Howe BM, Ringler MD. Predictive value of joint fluid volume on advanced pre-procedure imaging related to success of arthrocentesis and presence of septic arthritis.
Emerg Radiol 2024;
31:491-497. [PMID:
38844659 DOI:
10.1007/s10140-024-02244-y]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Accepted: 05/17/2024] [Indexed: 07/31/2024]
Abstract
PURPOSE
Septic arthritis is a dangerous medical condition requiring prompt diagnosis, often via arthrocentesis. A "dry tap" occurs when no fluid is aspirated. We hypothesized that the absence of a joint effusion on pre-procedure advanced imaging would reliably predict a dry tap and exclude septic arthritis.
METHODS
A cohort of 217 arthrocentesis cases of large joints (hips, shoulders, knees) from our institution, with pre-procedure advanced imaging (CT, MR, US) of the same joint performed within the previous 48 h, was analyzed. Exclusion criteria included non-native joints or inadequate imaging of the affected joint. These cases underwent blinded review by 4 radiologists who measured the deepest pocket of joint fluid on the pre-procedure imaging. Wilcoxon rank-sum test was performed comparing joint fluid pocket size to outcomes of successful aspiration and final diagnosis.
RESULTS
A smaller average joint pocket fluid size was present on advanced imaging in both dry taps compared with successful arthrocenteses (p < .0001), and in uninfected joints compared with septic joints (p = .0001). However, the overlap of values was too great to allow for a perfectly predictive cutoff. 29% (5/17) of patients with no visible joint fluid on pre-aspiration imaging underwent successful arthrocentesis, one case representing septic arthritis.
CONCLUSION
Volume of joint fluid on advanced pre-arthrocentesis imaging cannot reliably predict subsequent dry tap nor exclude septic arthritis.
Collapse