E1939. Ultrasound Evaluation of Elbow Ulnar Collateral Ligament in Collegiate Baseball Pitchers
Authors
ziang Lu;
University of California, Los Angeles
Nicholas Lobb;
University of Southern California
Emma Long;
University of Southern California
Kira Chow;
University of California, Los Angeles
Lori Michener;
University of Southern California
Objective:
The elbow ulnar collateral ligament (UCL) is frequently injured in baseball pitchers since it supports against valgus torque during pitching. Prior studies have shown morphologic changes seen on ultrasound in the UCL between pitching and non-pitching arms of professional pitchers. Our study aims to assess for ultrasound quantitative and qualitative differences in the UCL between pitching and non-pitching arms of collegiate pitchers.
Materials and Methods:
Forty-one NCAA division I collegiate pitchers were included in the study. Exclusion criteria included history of elbow UCL repair, current elbow pain with pitching, and history of arm injury with more than two weeks of missed time. Ultrasound cine loops of the pitching and non-pitching arms focused on the anterior band of the UCL were acquired at rest with 90-degree elbow flexion. Representative images from each cine loop were then selected for quantitative measurements and qualitative grading of UCL degenerative features. For quantitative measurements, UCL thickness at the proximal and distal attachments were measured using a Modified-Jacobson method (measurements taken perpendicular to the length of the ligament with exclusion of the underlying fat). For qualitative measurements, the UCL was scored from a scale of 0 (normal without degenerative features) to 3 (full thickness discontinuity) for degenerative change. The presence of calcification and enthesopathy was also noted.
Results:
The distal UCL thickness was higher for the pitching arm (mean 1.3 mm) relative to the non-pitching arm (mean 1.1 mm), p < 0.05 (95% confidence interval 0.1- 0.3 mm). The proportion of UCL with enthesopathy was higher for the pitching arm (10/41 = 24.4%) relative to the non-pitching arm (3/41 = 7.3%), p < 0.05. The pitching arm UCL also demonstrated higher degenerative scores relative to the non-pitching arm UCL, p < 0.05. There was no statistically significant difference in proximal UCL thickness or proportion of UCL calcification between the pitching and non-pitching arms.
Conclusion:
Ultrasound is a useful modality for evaluation of the elbow ulnar collateral ligament. Our study showed both quantitative and qualitative differences between the pitching and non-pitching elbow ulnar collateral ligaments in collegiate pitchers.
