Evidence-based use of clinical examination, ultrasonography, and MRI for diagnosing ulnar collateral ligament tears of the metacarpophalangeal joint of the thumb: systematic review and meta-analysis.

• Clinical examination followed by ultrasonography is the most appropriate test for ruling out ulnar collateral ligament (UCL) tears of the thumb. • MRI and ultrasonography both have high specificities to confirm the presence of a suspected UCL tear. • MRI outperforms ultrasonography for differentiating non-displaced from displaced UCL tears.