Evaluating Accuracy of Plain Magnetic Resonance Imaging or Arthrogram versus Wrist Arthroscopy in the Diagnosis of Scapholunate Interosseous Ligament Injury.

 Scapholunate interosseous ligament injury (SLIL) is the most common cause of wrist instability and a cause of morbidity in a proportion of patients with wrist injuries.  To evaluate the accuracy of plain magnetic resonance imaging (MRI) and MR arthrogram (MRA) in the diagnosis of SLIL injury against the existing gold standard-wrist arthroscopy.  We retrospectively reviewed 108 cases by comparing MRI/MRA reports and their wrist arthroscopy operation notes.  Overall MRI sensitivity to SLIL injuries was 38.5% (91.0% specificity). When broken down into plain MRI and MRA the results were: plain MRI sensitivity = 19.2% (91.4% specificity) and MRA sensitivity = 57.7% (90.5% specificity).  Neither MRI nor MRA scanning is sensitive enough compared with the gold standard. Positive predictive value remains too low (62.5 and 88.2%, respectively) to consider bypassing diagnostic arthroscopy and treating surgically. The negative predictive value (60.4 and 63.6%, respectively) is inadequate to confirm exclusion of injury from MRI results alone.