Sensitivity and Specificity of MRa and MRI Compared to Diagnostic Arthroscopy in Pediatric and Young Adult Shoulder Stabilization Surgery.

Background: Magnetic resonance arthrography (MRa) is considered superior to magnetic resonance imaging (MRI) in detecting glenoid labral pathology, although both are used in clinical practice with varying accuracy. Diagnostic arthroscopy remains the gold standard. In the pediatric and young adult population, limited data exist comparing MRa/MRI to arthroscopy in detecting superior labrum anterior and posterior (SLAP) lesions in cases of shoulder instability. Purpose: To evaluate the effectiveness of MRa/MRI in identifying various labral pathologies in a pediatric and young adult population with shoulder instability. Study Design: Cohort study (Diagnosis); Level of evidence, 2. Methods: Patients who underwent shoulder stabilization surgery with MRa/MRI obtained prior to surgery were retrospectively reviewed. Lesions identified on imaging reports were compared to arthroscopic findings used as the gold standard, and sensitivity and specificity were calculated for both MRI and MRa for anterior, posterior, and SLAP lesions. The percentage of time the imaging report was fully correct in identifying the integrity of the glenoid labrum in all 3 regions was calculated. Results: A total of 340 cases met inclusion criteria (297 MRa, 43 MRI). The mean age at surgery was 16.9 ± 1.8 years. There were no statistically significant differences between MRI and MRa in the anterior, posterior, or SLAP lesion groups. The imaging report was correct in fully diagnosing the integrity of the glenoid labrum in all 3 regions 63% of the time. Conclusion: There is no significant difference between MRa and MRI in detecting anterior, posterior, or SLAP lesions in the pediatric/young adult population. Imaging fails to fully diagnose the integrity of the labrum 37% of the time, and caution should be taken when interpreting imaging reports prior to diagnostic arthroscopy.