Utility of magnetic resonance imaging for detection of longitudinal split tear of the ulnotriquetral ligament

Abstract

Purpose: Wrist magnetic resonance imaging (MRI) has established utility in the diagnosis of wrist ligament tears, including complete tears of the ulnotriquetral ligament (UTL) and other components of the triangular fibrocartilage complex. A new type of longitudinal split tear of the UTL has recently been described with no imaging correlate. Our aims were to describe putative MRI findings associated with longitudinal UTL split tears and to assess diagnostic accuracy.

Methods: We randomly selected 40 patients with arthroscopically proven longitudinal UTL split tears and 20 patients with intact UTLs, all of whom had preoperative 3 T MRI of the same wrist performed, from a list of operative notes spanning from January 1997 through October 2011, filtered with the terms "ulnotriquetral ligament" and "ulnar triquetral ligament." Two musculoskeletal radiologists who were blinded to surgical results and clinical information independently reviewed the exams. They recorded the degree of certainty of whether a longitudinal UTL split tear was present and whether several other hypothesized associated abnormalities were present.

Results: Overall sensitivity for definitive longitudinal UTL split tear detection on MRI was 58% for reader 1 and 30% for reader 2. Specificity was 60% for both. There were no statistically significant discriminatory findings.

Conclusions: Among a selected group of patients who all had wrist arthroscopy, preoperative noncontrast 3 T wrist MRI had poor sensitivity and specificity for detection of the longitudinal split type of UTL tear. To date, MRI may be more helpful to exclude potential alternative diagnoses in the patient with ulnar wrist pain.

Keywords: Longitudinal split tear; ulnotriquetral ligament tear.