Ulnar collateral ligament injuries of the thumb: Does ultrasound get a thumbs up?

Abstract

Ulnar collateral ligament (UCL) injuries at the thumb metacarpophalangeal joint (MCPJ) commonly result from hyper-abduction during sports or falls. Differentiating partial from complete UCL tears, including Stener lesions, can be challenging in acute settings. While ultrasound provides a rapid and accessible diagnostic tool, its accuracy in predicting surgical findings remains uncertain. A retrospective review of patients with suspected UCL injuries who underwent ultrasound at CDDFT over five years was conducted. Inclusion criteria were ultrasounds indicating complete UCL tears or Stener lesions. Operative findings were used as the gold standard for diagnosis. Of 50 patients, 19 met the inclusion criteria. Complete UCL tears were confirmed intraoperatively in 11 patients (63%), while 6 (37%) had intact ligaments, yielding a positive predictive value of 63% for ultrasound. Ultrasound is a valuable tool for diagnosing UCL injuries but shows limitations, with a 37% false-positive rate. Supplementary imaging may improve diagnostic accuracy.