MR arthrogram outperforms MRI 2 weeks after shoulder dislocation

The aim of this study was to determine the comparative accuracy and precision of routine Magnetic Resonance Imaging versus MR arthrogram in measuring labral tear size as a function of time from a shoulder dislocation. We hypothesized that MRI would demonstrate a time-dependent loss of accuracy and precision in determining tear extent, with a threshold at which point the value of MRI arthrogram would exceed that of an MRI, and that MR arthrogram would not demonstrate time-dependence. We found that compared to MR Arthrogram, conventional MRI demonstrates time-dependent loss of accuracy and precision in determining shoulder labral tear extent following dislocation, with statistical divergence occurring at 2 weeks.