Comparison of Radiographic and Ultrasound Imaging Techniques for Assessing the Scapholunate Interval in Healthy...

Background/Objectives: Ultrasound (US) is a valuable tool in hand surgery because of its portability, low cost, and ability to provide noninvasive, real-time evaluation of soft tissue structures. However, it has not been widely assessed for measuring the scapholunate (SL) interval using dynamic stress views. This study aimed to determine whether ultrasound provides comparable measurements to radiography when evaluating the SL interval in healthy subjects. Methods: We analyzed 29 wrists from 29 individuals. Each wrist underwent dynamic stress maneuvers while the SL interval was measured with both radiography and US. The following views were obtained: neutral rotation, ulnar deviation, clenched fist, and a modified dynamic clenched fist view. The latter was performed by applying pressure on the head of the third metacarpal from distal to proximal. Results: The SL interval could be visualized in the clenched fist and ulnar deviation radiographic views, as well as in the modified dynamic clenched fist US view. Ultrasound in the neutral position produced measurements similar to those of traditional stress radiographs. The most pronounced changes in the SL interval occurred between neutral and dynamic views, whether assessed by radiography or US. There was no significant difference in the magnitude of interval change between the two imaging modalities. Conclusions: Ultrasound with dynamic stress maneuvers provided similar dynamic SL interval changes to stress radiographs in healthy individuals. A modified stress view using a slightly clenched fist and manual pressure on the third metacarpal head may offer hand surgeons a simple, real-time tool to noninvasively evaluate SL instability.