Evaluation of Dorsal Scaphoid Displacement Using Posterior Radioscaphoid Angle in Patients With Suspected Scapholunate Instability: A Preliminary Study

Purpose To assess the validity and reliability of posterior radioscaphoid angle (PRSA), an indicator dorsal displacement scaphoid, in distinguishing wrists with without chronic scapholunate instability (SLI). Methods We prospectively evaluated 40 patients (22 men 18 women; mean age, 46 ± 13 years) suspected SLI radiographs computed tomography arthrography. Based on these data, 3 groups were defined: positive (n = 16), negative 19), questionable 5). An independent reader measured PRSA sagittal images using same procedure. Results The median values significantly lower group (98°) compared (110°) (111°) groups. difference between was not significant. best differentiation obtained a threshold value 103° (specificity 86% sensitivity 79%). Conclusions In this preliminary study, analysis offers quantitative tool for evaluation scaphoid cases SLI, including presenting initial radiography findings. Type study/level evidence Diagnostic II.