Assessment Strategies for Distal Radioulnar Joint Instability: Current State and a Need for Improved Tools

The distal radioulnar joint (DRUJ) plays a crucial role in wrist and forearm motion by facilitating pronation and supination while transmitting forces between the ulna and carpus. The stability of the DRUJ is dependent on both bony and soft tissue structures; however, because of the variability in joint congruence during wrist motion, soft tissue stabilizers are more critical for maintaining stability. The primary static soft tissue stabilizer of the DRUJ is the triangular fibrocartilage complex. Various clinical tests, such as the ballottement test, ulnar fovea sign, and press test, are commonly used to assess DRUJ stability. However, these tests are often considered subjective, exhibiting variable reliability and reproducibility. Although imaging techniques such as radiography, computed tomography, and magnetic resonance imaging have been employed, they present challenges related to cost, accessibility, patient tolerance, radiation exposure, and inability to detect dynamic instability at the DRUJ. Additionally, although ultrasound shows some promise in detecting dynamic instability, it remains highly operator-dependent, especially for evaluation of the DRUJ. Future efforts to develop reliable and quantifiable methods for analyzing DRUJ instability are essential for improving the management and treatment of this condition.