Ultrasonographic stress testing of ulnar collateral ligament injuries of the thumb.

We compared ultrasonographic stress test evaluation to clinical examination of ulnar collateral ligament injuries to the thumb. The results of the sonographic and clinical examinations were compared to either operative findings or clinical follow-up results if conservative treatment was elected. Of 25 patients, the clinical grade injury was identified correctly in 25 with ultrasonography compared to 24 with clinical examination. Of the grade III tears, ultrasonography missed two patients with Stener tears and physical examination misidentified or missed four patients with Stener tears. These results confirm the experience of others that ultrasonography is a useful method to evaluate injury to the ulnar collateral ligament of the thumb.