Ultrasonographic evaluation of degenerative changes in the distal radioulnar joint: correlation of findings with gross anatomy and MR arthrography in cadavers.

OBJECTIVE

To determine the accuracy of ultrasonography (US) in the evaluation of degenerative changes in the distal radioulnar joint (DRUJ).

METHODS AND MATERIALS

Ten cadaveric specimens were obtained. US evaluation of cartilage degeneration and thickness was performed by two independent and blinded readers (R1 and R2). Gross anatomy and MR arthrography evaluated by two readers in consensus served as the reference standard. The joint surface not accessible to US was measured.

RESULTS

US interreader agreement was non-existent for cartilage thickness measurements and moderate for cartilage degeneration grading (weighted kappa = 0.41). Comparing US and MR imaging evaluation, there was no correlation between US R1 and MR imaging (Pearson correlation coefficient [PCC] = 0.352) and a moderate correlation between US R2 and MR imaging (PCC = 0.570) concerning cartilage thickness measurements. Concerning cartilage degeneration grading, there was a moderate to strong (R1 Spearman correlation coefficient [SCC] = 0.729)/R2 SCC = 0.767) correlation concerning cartilage degeneration grading. Comparing US and gross anatomic evaluation, there was no correlation for US R1 (PCC = 0.220) and a strong correlation for US R2 (PCC = 0.922) concerning cartilage thickness measurements, and a strong to moderate correlation (R1 SCC = 0.808/R2 SCC = 0.597) concerning cartilage degeneration grading. The mean sector of the articular surface of the ulna head not accessible to US was 13°.

CONCLUSION

In conclusion the DRUJ is accessible to US except in the central 13° sector of the joint surface. US was approved to be sufficient in demonstrating advanced stages of cartilage degeneration. Thus, US of the DRUJ is recommended in patients suffering from ulnar-sided wrist pain.