Comparison between high-resolution MRI with a microscopy coil and arthroscopy in triangular fibrocartilage complex injury.

PURPOSE

To determine whether high-resolution magnetic resonance imaging (MRI) could detect injuries to the triangular fibrocartilage complex (TFCC).

METHODS

Eleven patients who showed both a positive sign during the ulnocarpal stress test and tenderness at the distal end of the ulna had a high-resolution MRI using a 47-mm diameter microscopy coil. Six regions of the TFCC were investigated for injury: the radial attachment, disc, ulnar attachment of the triangular fibrocartilage (TFC), ulnotriquetral ligament, palmar radioulnar ligament (PRUL), and dorsal radioulnar ligament (DRUL). Arthroscopy was performed subsequently on each patient.

RESULTS

For injuries to the radial attachment or the disc of the TFC, a high-resolution MRI showed 100% sensitivity and 100% specificity compared with arthroscopy. In 3 cases in which injury to the ulnar attachment of the TFC was detected with MRI and examination showed a positive piano-key sign and distal radioulnar joint instability, only 1 injury was confirmed with arthrotomy. For MRI diagnosis of an ulnotriquetral ulnolunate attachment injury, the sensitivity was 100% and the specificity was 70%; however, 3 cases had false-positive results. Finally MRI had 100% sensitivity for detecting DRUL and PRUL injuries, although specificities were 75% and 83%, respectively. With MRI there were 2 false-positive DRUL injury diagnoses and 1 false-positive PRUL injury diagnosis.

CONCLUSIONS

High-resolution MRI using a microscopy surface coil allowed assessment of each TFCC component and showed a higher accuracy for diagnosing injuries to the radial attachment and the disc of the TFC compared with previous studies. High-resolution MRI, however, was not able to diagnose DRUL, PRUL, or ulnolunate ligament injuries accurately.

TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic III.