3-T MRI Versus Arthroscopy to Diagnose Intrinsic Wrist Ligament and TFCC Tears

3-T MRI Versus Arthroscopy to Diagnose Intrinsic Wrist Ligament and TFCC Tears

A recent study has compared 3-T MRI (3 Tesla magnetic resonance imaging) of the wrist and MR arthrography with arthroscopy in the diagnosis of intrinsic wrist ligament injury and triangular fibrocartilage complex (TFCC).

The study, published in AJR, has shown that the rate of sensitivity of ligamentous and cartilaginous wrist tears using 3-T MRI hovers above 82%, with a specificity of 100%.

The Study
Over a 7-year period, patients with conventional wrist MR examinations were identified, and results of these studies were reviewed by 2 radiologists. Patients who had also undergone MR arthrography after conventional MRI were identified.

Methodology
Radiologists were blinded to the arthroscopy results. Criteria used for diagnosis of a wrist ligament or TFCC tear on arthrography were visualization of the tear and abnormal communication of the joint spaces.

Microperforation was noted to be abnormal communication of the joint spaces without visualization of the tear. When available, results were compared with findings at arthroscopy if the arthroscopy was performed within 75 days of the MR exam.

Results
300 MR examinations of the wrist were identified over the 7-year period. The radiologists reviewed all 300 cases in order not to introduce bias since they did not know which studies were read as positive for ligament or TFCC tears.

Thirty-five patients also underwent MR arthrography; 49 patients eventually underwent arthroscopy.

On arthroscopy, 22 patients had TFCC tears, 19 had scapholunate tears, and 11 had lunatotriquetral tears. There were no false-positive readings of ligament tears or TFCC tears on MRI when using arthroscopy as the standard.

MR sensitivity for TFCC tears was determined to be 86%, with a specificity of 100%.

For scapholunate ligament tears, the sensitivity was 89% and the specificity was 100%.

The sensitivity for lunatotriquetral tears was 82%, with a specificity of 100%.

For those who also underwent MR arthrography, there was increased sensitivity for ligament and TFCC tears, although there were an additional 3 false-positive results.

Conclusions
“MRI at 3-T is sensitive and specific for detection of wrist ligament tears. MR Arthrography is more sensitive for ligament evaluation but can result in false-positive findings because of microperforations.”

Reviewer’s Comments
These findings are an improvement to previously published reports of ligamentous tears and TFCC injury for 1.5-T MRI of the wrist. For 1.5-T MRI compared with arthroscopy, the majority of calculated sensitivities on prior studies hovered in the 50% to 60% range, whereas the current study demonstrated sensitivity >82% for all evaluated wrist tears.

The findings with MR arthrography reveal marginal benefit for this modality, with an increased false-positive rate.

However, usage of MR arthrography in otherwise normal-appearing MR examinations in patients with a high clinical concern for ligamentous or cartilaginous tears may be warranted based on these data.

Author: Basil Hubbi, MD
Reference:

Magee T. Comparison of 3-T MRI and Arthroscopy of Intrinsic Wrist Ligament and TFCC Tears. AJR; 2009;192 (January): 80-85.