Diagnostic Imaging of Ulnar Collateral Ligament Injury: A Systematic Review.

Background: Ulnar collateral ligament (UCL) injuries can be debilitating in overhead athletes. Accurate diagnosis is important; however, several imaging modalities are available for the assessment of UCL injuries.
Purpose: To provide a comprehensive review of published literature regarding the diagnostic capabilities of different imaging modalities for UCL tears.
Methods: PubMed, Medline, and Embase were queried for peer-reviewed literature published between January 1947 and June 4, 2019, pertaining to diagnostic imaging of UCL tears. Articles assessing static and stress radiography, ultrasound, magnetic resonance imaging (MRI), MRI with arthrography (MRA), and computed tomography arthrography of the UCL were included. Studies were excluded if imaging results were not compared with intraoperative diagnosis, as intraoperative findings are generally considered the gold standard for diagnostic comparison. The articles were assessed per the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses) guidelines and reviewed with the Quality Assessment of Diagnostic Accuracy Studies, version 2 (QUADAS-2) assessment.
Results: The literature search yielded 2478 articles, of which 15 were included in this review. Potential bias was noted in each QUADAS-2 subsection. Multiple studies demonstrate an association between UCL tears and osseous abnormalities identified on static radiographs; however, the use of static or nonstressed radiographs is not recommended for specific evaluation of UCL injuries. Conventional ultrasound was 81% sensitive and 91% specific, as compared with 96% and 81% for stress ultrasound, respectively. The sensitivity and specificity of MRI ranged from 57% to 100% and 89% to 100%. The sensitivity of computed tomography arthrography ranged from 63% to 86%. The sensitivity and specificity of MRA ranged from 81% to 100% and 91% to 100%.
Conclusion: Of the currently available imaging modalities, MRA provides the best combination of sensitivity and specificity of the evaluation of the UCL. Further research comparing ultrasound with MRA is needed.