The Ultrasonography (US) emerges as a reliable instrument for analysing subtalar joint (STJ) synovitis among rheumatoid arthritis (RA) patients, according to recent research published in the Journal of Rheumatology.

Twelve sonographers directed a US reliability exercise with 10 RA cases with hindfoot pain by following a Delphi process. B-mode and power Doppler (PD) techniques assessed the anteromedial, posteromedial, and posterolateral STJ according to an agreed US protocol and a dichotomous score and 4-grade semiquantitative grading score for the presence of joint effusion (JE) and synovitis, respectively. Cohen's and Light's κ computed Intraobserver and interobserver reliability. Further, weighted κ coefficients with absolute weighting were estimated for B-mode and PD signal.

Mean weighted Cohen's κ reported for JE, SH, and PD were 0.52, 0.80, and 0.61, respectively. Weighted Cohen's κ determined for PD, JE, and SH in the anteromedial, posteromedial, and posterolateral STJ were 0.28–0.77; 0.31–1, –0.05 to 0.65, and –0.2 to 0.69; 0.66–1, 0.52–1, and 0.42–0.88; and –0.04 to 0.79, 0.42–0.95, respectively. Further, weighted Light's κ for JE, SH, and PD were 0.16, 0.67, and 0.46, respectively. Weighted Light's κ determined for PD, JE, and SH in the anteromedial, posteromedial, and posterolateral STJ were 0.33, 0.09, and 0.63; 0.35, 0.04, and 0.49; and 0.66, 0.18, and 0.82, respectively. According to all these measurements, the US was efficient in assessing synovitis of STJ.