Validating Clinical Distal Radioulnar Joint Examination With Radiographic Parameters

Area of Science:

• Orthopedics
• Radiology
• Biomechanics

Background:

• Assessing distal radioulnar joint (DRUJ) instability often relies on comparing injured and uninjured wrists.
• The in vivo displacement of bilateral DRUJs during resisted forearm rotation has not been extensively quantified.

Purpose of the Study:

• To quantify the in vivo displacement of bilateral distal radioulnar joints (DRUJs) during resisted pronosupination.
• To determine if there is a significant difference between left and right DRUJ displacement.
• To validate the use of the contralateral wrist as a control in dynamic imaging studies.

Main Methods:

• Thirty-two participants without wrist pathology underwent dynamic computed tomography (CT).
• Bilateral forearm rotation was evaluated in neutral, 60° pronation, and 60° supination with maximal isometric muscle loading.
• DRUJ alignment and subluxation were assessed using a modified radioulnar line method.

Main Results:

• No significant difference in mean DRUJ displacement was observed between the right and left sides across all tested positions (neutral, pronation, supination).
• While a statistically significant difference in pronation displacement was noted between males and females, overall displacement measurements were highly consistent (86% within 1 mm).

Conclusions:

• Dynamic CT demonstrates symmetry in bilateral DRUJ displacement during resisted pronosupination.
• The findings support the contralateral wrist as a reliable control for identifying instability in the ipsilateral wrist.