A new quantitative evaluation system for distal radioulnar joint instability using a three-dimensional...

Area of Science:

• Orthopedics
• Biomechanics
• Medical Instrumentation

Background:

• Assessing distal radioulnar joint (DRUJ) instability lacks objective evaluation methods.
• Current methods for evaluating DRUJ instability present challenges in accuracy and objectivity.

Purpose of the Study:

• To develop a non-invasive measurement method for quantitatively assessing normal DRUJ movement.
• To characterize DRUJ movement in healthy volunteers using a 3D electromagnetic sensor system (EMS).

Main Methods:

• EMS was used to measure DRUJ movement in block and saw bone models, assessing accuracy and reproducibility.
• In vivo measurements involved attaching sensors to the distal radius and ulnar head in 14 healthy volunteers.
• Dorsovolar translation was measured using EMS and ultrasonography, with correlation coefficients calculated. Intra- and inter-rater reliability were assessed using ICCs.

Main Results:

• EMS demonstrated high accuracy and reproducibility in assessing DRUJ movement.
• A high correlation coefficient (0.920) was found between EMS and ultrasonography measurements.
• Mean ulnar head translation was 6.00 ± 1.16 mm, with high intra-rater (0.856) and inter-rater (0.868) reliability.

Conclusions:

• The EMS method provides accurate, reproducible, and reliable assessment of DRUJ movement.
• The study established a normal dorsovolar ulnar head translation of 6.00 mm in healthy individuals.
• EMS offers an objective, non-invasive, real-time assessment tool for DRUJ dynamics, aiding in the treatment of instability.