Application of force-monitor ultrasonography to assess distal radioulnar joint instability in patients with triangular fibrocartilage complex injury

Introduction In this study, we evaluated the differences and measurement accuracy in the force-displacement relationship of the distal radioulnar joint (DRUJ) between patients with triangular fibrocartilage complex (TFCC) injury and healthy controls using force-monitor ultrasonography.Methods This study included 11 TFCC injury patients and 22 healthy controls. We evaluated differences in the force-displacement relationship of the DRUJ in these patients using force-monitor ultrasonography. Cyclic compression was applied to the dorsal surface of the ulnar head. Distance between the dorsal surface of the distal radius and ulnar head at the DRUJ level was measured in the initial and pressed-down positions. Changes in radioulnar displacement, applied force, and displacement-to-force ratio were measured. Furthermore, we compared the parameters between the affected and unaffected wrists and between TFCC injury patients and controls.Results The radioulnar displacement and displacement-to-force ratio were significantly larger in the affected wrists than in the unaffected wrists (P = 0.003 and P = 0.02). The affected/unaffected side ratio of radioulnar displacement and displacement-to-force ratio were significantly larger in the TFCC injury patients than in the controls (P = 0.003 and P = 0.02). The area under the curve was 0.82 for the affected/unaffected ratio of the radioulnar displacement. The optimal cutoff value indicated by the receiver-operating characteristic curve for the affected/unaffected ratio of the radioulnar displacement was 1.71; the sensitivity and specificity were 82% and 86%, respectively.Conclusions Assessing the DRUJ instability with force-monitor ultrasonography may help identify TFCC-injured wrists.

引言 在本研究中，我们利用力监测超声评估三角纤维软骨复合体（TFCC）损伤患者与健康对照者之间远侧桡尺关节（DRUJ）力 - 位移关系的差异以及测量准确性。 方法 本研究纳入11例TFCC损伤患者和22例健康对照者。我们利用力监测超声评估这些患者DRUJ力 - 位移关系的差异。对尺骨头背侧表面施加循环压缩。在初始位置和下压位置测量DRUJ水平处桡骨远端背侧表面与尺骨头之间的距离。测量桡尺位移、施加力以及位移 - 力比值的变化。此外，我们比较了患侧与健侧手腕之间以及TFCC损伤患者与对照者之间的参数。 结果 患侧手腕的桡尺位移和位移 - 力比值显著大于健侧手腕（P = 0.003和P = 0.02）。TFCC损伤患者桡尺位移和位移 - 力比值的患侧/健侧比值显著大于对照者（P = 0.003和P = 0.02）。桡尺位移患侧/健侧比值的曲线下面积为0.82。桡尺位移患侧/健侧比值的受试者工作特征曲线所指示的最佳截断值为1.71；敏感度和特异度分别为82%和86%。 结论 用力监测超声评估DRUJ不稳定性可能有助于识别TFCC损伤的手腕。