Ultrasonographic evaluation of the first extensor compartment of the wrist in de Quervain's disease

This prospective cohort study was undertaken to explore the hypothesis that the retinaculum is thicker in de Quervain's disease and to identify another landmark for the presence of the intracompartmental septum. A case group (60 wrists) comprised of Korean female patients with unilateral de Quervain's disease and a healthy control group (60 wrists) were evaluated by ultrasonography. The case group underwent surgery for extensor retinacular release, and surgical findings were used as the reference standard. The mean extensor retinacular thickness in the case and control groups was compared using a Wilcoxon rank-sum test. A receiver operation characteristic curve was constructed for the parameter. The mean thickness of the extensor retinaculum was 0.94 mm (SD 0.37) in the case group and 0.35 mm (SD 0.07) in the control group, and this difference was significant. The cutoff value of the extensor retinaculum for diagnosing de Quervain's disease was 0.45 mm (sensitivity 96.3 %, specificity 93.3 %). Bony crests were found in all cases of presence of the intracompartmental septum and could be classified into three types according to shape. We concluded that the extensor retinaculum is thicker in de Quervain's disease. And the bony crest on the radial styloid can be considered a new landmark for determining the presence of an intracompartmental septum. Diagnostic, level II.