2025 ISAKOS Congress in Munich, Germany

2025 ISAKOS Biennial Congress Paper


One Third of Asymptomatic United States Based Youth Baseball Players Exhibited Subapophyseal Avulsions: An Ultrasound Study

James McGinley, BS, Dallas, Texas UNITED STATES
Cassidy Morgan Schultz, BS, Dallas, TX UNITED STATES
Robert Van Pelt, MPH, Dallas, TX UNITED STATES
Charles W Wyatt, CPNP, Plano, Texas UNITED STATES
Katie Sloma, PT, DPT, CSCS, Dallas, TX UNITED STATES
Sophia Ulman, PhD, Dallas, Texas UNITED STATES
Brandee D. Schmidt, PT, MS, DPT, Frisco, TX UNITED STATES
Monique Prebensen, ATC, Dallas, TX UNITED STATES
Jacob Jones, MD, Dallas, TX UNITED STATES
Philip Wilson, MD, Dallas, TX UNITED STATES

Texas Scottish Rite, Dallas, TX, UNITED STATES

FDA Status Not Applicable

Summary

In a cohort of healthy, United States-based youth baseball players, one-third demonstrated an active or united avulsion of the medial epicondyle on their dominant elbow while capitellar osteochondral abnormalities were minimal.

Abstract

Objectives:
Repetitive throwing in youth baseball places athletes at risk for elbow injuries, and ulnar collateral ligament (UCL) subapophyseal avulsions are increasingly recognized (1). Ultrasound may be an effective technique to examine youth baseball elbows (2), particularly among the less-studied healthy population. The study aim was to evaluate asymptomatic elbows in youth baseball players for evidence of medial epicondylar avulsive changes at the origin of the UCL.

Methods

After IRB approval, youth baseball players under 19 years without physician care in the prior six months were recruited during three club baseball ultrasound screening sessions. Basic demographics and sports participation history were obtained. Patient-reported outcomes included the Single Assessment Numeric Evaluation (SANE), The Hospital for Special Surgery Pediatric Functional Activity Brief Scale (Pedi-FABS), and the American Shoulder and Elbow Surgeons (ASES) score. Medial epicondyle avulsions, radiocapitellar osteochondral changes, and indirect humeral torsion angles (3) were assessed via ultrasound exam from one fellowship-trained physician using a 4-20 MHz High Frequency Linear transducer with a GE Venue Go portable ultrasound machine (Venue Go R4, GE HealthCare, Chicago, Illinois, USA). Descriptive statistics and Kruskal-Wallis comparisons were run between avulsive and non-avulsive groups (95% CI).

Results

A total of 156 arms in 80 male athletes were evaluated (12.4±1.7 years). Athletes played baseball for 6.6±2.7 years with Pedi-FABS scores of 24.0±5.5. Dominant elbows were rated as 93.5±9.5 (out of 100; SANE) and dominant shoulders were rated 91.2±14.4. On the dominant medial epicondyle, 27/78 (34.6%) elbows showed evidence of a sub apophyseal avulsion: eleven active avulsions (14.1%) and sixteen united avulsion fragments (20.5%). No medial epicondyle changes were visible on the non-dominant elbow. One athlete demonstrated capitellar osteochondral changes (subchondral plate flattening) within the dominant arm, and another player demonstrated osteochondral changes in both arms (subchondral plate concavity in dominant, subchondral plate flattening in non-dominant). Those players with medial epicondyle avulsions demonstrated no differences in humeral retrotorsion or elbow pain on exam compared to those without elbow lesions. 11.1% of players who showed evidence of sub apophyseal avulsion reported playing pitcher, 44.4% reported playing infield, 3.7% reported playing outfield and25.9% reported playing pitcher.

Conclusion

In a cohort of healthy, United States-based youth baseball players, one-third demonstrated an active or united avulsion of the medial epicondyle on their dominant elbow while capitellar osteochondral abnormalities were minimal. Ultrasound injury surveillance may provide a useful tool in youth baseball players to identify subclinical medial epicondyle subapophyseal injuries prompting earlier treatment and injury prevention strategies.

References:

1. Sinha, R., Wyatt, C. W., Althoff, C., Jones, J. C., Johnson, B., Ellis, H. B., & Wilson, P. L. (2024). Avulsion and Soft Tissue Injuries of the Ulnar Collateral Ligament in Children and Adolescents. The American journal of sports medicine, 3635465241252156. Advance online publication. https://doi.org/10.1177/03635465241252156
2. Matsuura T, Suzue N, Iwame T, Iwase J, Yokoyama K, Takao S, Nishio S, Sairyo K. Prevalence of osteochondritis dissecans of the capitellum in elementary school baseball players based on ultrasonographic screening: a 15-year overview in Tokushima, Japan. JSES Int. 2024 Feb 14;8(3):661-666. doi: 10.1016/j.jseint.2024.01.011. PMID: 38707578; PMCID: PMC11064688.12;2(8):2325967114545298. doi: 10.1177/2325967114545298. PMID: 26535356; PMCID: PMC4555579
3. Takeuchi S, Yoshida M, Sugimoto K, Tsuchiya A, Takenaga T, Goto H. The differences of humeral torsion angle and the glenohumeral rotation angles between young right-handed and left-handed pitchers. J Shoulder Elbow Surg. 2019 Apr;28(4):678-684. doi: 10.1016/j.jse.2018.09.002. Epub 2018 Nov 27. PMID: 30502031.